Tuberculosis is a dangerous socially significant  disease  of  various  animal  species. According  to  Rosselkhoznadzor  data  for 2022, the situation with bovine tuberculosis is endemic, stable, long-term trends are decreasing,  epidemic  thresholds  for  ill  health and  incidence  have  not  been  overcome.  It should be noted that in 2022, bovine tuberculosis was not officially detected, but this infection was registered in several pigs and wild boars. Take a point that the reduction in the number of cases of tuberculosis in cattle is decreased (to zero), the overall strategy for combating this disease is successful, but this does not mean that the need to develop new tests  for  the  accelerated  diagnosis  of  this infection  has  completely  disappeared.  The safety of service personnel directly depends on  minimizing  the  risk  of  infection  with pathogens common to humans and animals, one of which is tuberculosis. The fastest way to indicate infectious agents is by immunochromatographic  analysis.  This  publication is devoted to the details that it is desirable to focus on when developing a diagnostic test based on immunochromatographic analysis, using the example of bovine tuberculosis. As an antigen in the presented study, native antigens of Mycobacterium bovis grown on a nutrient  medium  Levenshtein-Jensen  with proven antigenic activity were used. Conjugation of antispecies antibodies was carried out  with  a  colloidal  solution  of  gold, (diameter  of  particle  is  25±0,9  nm).  In  the course  of  the  work,  the  optimal  conditions for the manufacture of a diagnostic test for the detection of anti-tuberculosis antibodies by  immunochromatographic  analysis  were shown.

The article presents the results of studying  the  formation  of  specific  immunity  in piglets during vaccination against circovirus infection. Circovirus diseases of pigs, manifested by the defeat of many body systems, are  widespread  and  cause  great  economic damage in industrial pig farms. The study of the  formation  of  specific  immunity  during vaccination of piglets against circovirus infection is of scientific and practical interest. The purpose of the research is to study the formation  of  specific  immunity  in  piglets during vaccination against circovirus infection. It was found that vaccination is accompanied by activation of the innate immunity system, which initiated the launch and formation  of  an  antigen-specific  adaptive  immune response. In animals 6 days after the introduction of the vaccine, compared with intact piglets, an increase in the content of pro-inflammatory  cytokines  IL-1ß,  TNF-α, IFN-α and IFN-γ and the anti-inflammatory mediator IL-4 was found, indicating a cellular  and  humoral  immune  response.  An  increase in the indices of inflammatory activity of mediators and the ratio of pro- and anti-inflammatory cytokines indicates an increase in the activity of T-helper I and the prevalence  of  cellular  immune  response.  Under the influence of technological stress caused by weaning from sows and transfer to rearing,  animals  14  days  after  vaccination showed a decrease in the level of IL-2, IFN-α and IFN-γ, inducing cellular immunity, as well as cytokine index, the ratio of pro- and anti-inflammatory  mediators,  which  indicates a shift in the direction of the immune response in the side of activation of the functioning  of  T-helper  II,  indicating  the  predominant formation of humoral immunity.

Marek's disease is a dangerous immunosuppressive  viral  disease  of  poultry.  Most egg poultry farm in the Russian Federation vaccinate their chickens on the first day of life against this viral disease. Thanks to this vaccine prevention tactic, poultry farms protect  themselves  from  the  outbreak  of  this disease and economic damage. Traditionally, among  the  viruses  related  to  this  disease, there are the 1st serotype of the Marek's disease  virus  (Gallid  alphaherpesvirus  2)  and the 3rd serotype of the Marek's disease virus, which is not such in a strict taxonomic sense (Meleagrid  alphaherpesvirus  1,  also  called turkey herpesvirus). When poultry is infected, this virus causes a significant change in the expression of the main immunity genes (IL6,  PTGS2,  IRF7).  Based  on  the  results obtained, it was concluded that the expression of the IL6 and PTGS2 genes was slightly  higher  than  the  level  of  expression  of these genes in the control group. It is possible  that  local immunity  was  suppressed by the  immunosuppressive  properties  of  the Marek's  disease  virus.  When  studying  the expression of the IRF7 gene, a strong effect of viruses of both serotypes on this gene was found,  and  Gallid  alphaherpesvirus  2  exceeded the level of this effect compared to the  effect  of  Meleagrid  alphaherpesvirus  1 by 4 times. These results may indicate that sharply  increasing  expression  of  the  IRF7 gene may be a sign of Marek's disease virus replication (since Gallid alphaherpesvirus 2 and  Meleagrid  alphaherpesvirus  1  interact with the same cellular receptor, the vaccine effect  of  Meleagrid  alphaherpesvirus  1  is based  on  this).  On  the  other  hand,  we  can conclude that the introduction of these viruses does not cause inflammatory and immune reactions in the ileocecal tonsils of birds.

Innate immunity plays a decisive role in the primary reaction of the body to microbial agents. It is realized through the activation of cellular  and humoral  factors  of nonspecific resistance  –  neutrophils,  macrophages  and antimicrobial  and  regulatory  substances  secreted by them, which, in turn, trigger a cascade of reactions involving lymphocytes. On the surface of the mucous membranes and in mucosal secretions, neutrophils realize their function not only through phagocytosis, but also through the release of DNA and bactericidal granules that form neutrophil extracellular  traps.  Violation  of  the  functioning  of these  cells  on  the  surface  of  the  mucous membranes is considered as one of the factors of the formation of pathological microbial  communities,  leading  to  the  development of dysbiosis and inflammation of various localization. The completed character of phagocytosis  is  provided  by  microbicidal systems of leukocytes: cationic proteins and myeloperoxidase.  They  have  a  special  immunological  significance  and  influence  the course and outcome of the disease. Myeloperoxidase and cationic proteins are the main factors of bactericidal protection.

The formation of the level of zoosanitary protection  of  enterprises  is  reflected  in  the assignment  of  the  status  of  regionalization for  especially  dangerous  animal  diseases throughout the country. The Federal Service for  Veterinary  and  Phytosanitary  Surveillance ensures the safety of the territory of the Russian  Federation  from  the  introduction and spread of animal diseases. Assigning the level  of  compartmentalization  to  an  enterprise depends on compliance with the basic standards for the maintenance and breeding of  pigs,  as  well  as  the  processing  of  pig products. The assignment of the highest level of compartmentalization allows the company  to  sell  products  almost  without  restrictions, both within the subject of the Russian  Federation  and  between  subjects,  as well  as  for  export.  The  emergence  of  outbreaks of particularly dangerous diseases not only  in  Russia,  but  also  around  the  world causes  great  social  and  economic  damage. The World Organization for Animal Health is  developing  principles  for  ensuring  the biological  safety  of  the  territory.  Carrying out  preventive,  diagnostic  and  therapeutic measures at enterprises form an increase in the level of zoosanitary protection and ensuring the safety of the spread of the disease. The topic of the article is new and relevant today, since the level of compartmentalization of enterprises in the region confirms the zoosanitary status of the territory. The export of  meat  products  from  the  territory  of  the region depends on a number of factors, including  the  assigned  status  of  regionalization.  Increasing  the  export  potential  of  the region depends on the interaction of authorities  and  enterprises.  The  fulfillment  of  the conditions of the importing countries is the most important principle of export supplies. Many enterprises are deprived of the right to export only because of the formal approach of fulfilling the requirements that lead to the identification of violations during the preparation of export shipments and the certification  of  the  enterprise  for  inclusion  in  the registers of compartmentalization.

Feed  additives  based  on  organic  acids have a bactericidal and bacteriostatic effect that correlates with the input rate (dosage). The effect of the drugs is due to a cellular metabolic disorder of opportunistic bacteria and a change in the permeability of their cell membranes. The use of acid-based preparations helps to preserve the nutritional value of feed and prevent infection of animals and birds, which is an important aspect in maintaining  the  productivity  of  livestock.  This article examines the effectiveness of the new feed additive “Vitasil 2 Plus” against micro-organisms of the species Salmonella Enteritidis,  Escherichia  coli,  Pseudomonas  aeruginosa by adding to water and various types of raw materials and feed.

Epizootic strains isolated from pathological material from birds from poultry farms in the  Russian  Federation  were  used  as  test cultures. The effectiveness of the drug was studied at low and high input rates, depending  on  the  type  of  substrate  being  studied. The following substrates were used: drinking water,  granulated  feed,  powder,  fish  meal and  soybean  meal.  Simple  (meat  peptone agar),  selective  (staphylococcal  agar)  and differential  diagnostic  (Endo  medium,  xyloselysine  deoxycholate  agar -  XLD  agar) nutrient media were used in the work.

According  to  the  results,  it  was  found that the bactericidal and bacteriostatic effects of the feed additive, as a rule, correlate with high  and  low  input  rates.  As  a  result,  the effectiveness of the complex drug “Vitasil 2 Plus” has been proven against a number of microorganisms,  thereby  this  feed  additive can be used in the disinfection of feed and drinking water.

The purpose of these studies was to identify, identify, analyze and study the distribution of Cryptosporidium scrofarum in pigs in the  farms  of  the  Vologda  Region  of  the Northwestern Federal District of the Russian Federation.

For the first time in the Russian Federation, using the example of the Vologda Oblast of the Northwestern Federal District in pig  farms  of  various  types  using  the  latest molecular  genetic  methods,  namely  using high-throughput  sequencing  of  amplicon libraries of fragments of the 18S rRNA gene obtained  because  of  nested  PCR,  we  have established the infection of C. scrofarum in all  age  groups  of  examined  animals.  The contamination of animals kept in pig farms was 34%, in farms - 32.4%. Animals that are fattened at the age of 13-24 weeks are most susceptible to infection.

Analysis  of  ASV  taxonomic  affiliation using  phylogenetic  analysis,  supplemented by analysis using the blastn algorithm in the GenBank database, showed that a total of 10 ASV types (amplicon sequence variant) are present  in  all  tested  samples,  which  have high  similarity  to  sequences  deposited  in GenBank  as  fragments  of  the  18S  p  gene Cryptosporidium  scrofarum  RNA.  It  has been established that the types of ASV1 and ASV2  detected  in  various  geographical  regions of the world from Portugal and Great Britain  to  China,  India  and  Australia  are identified in all examined farms, although in significantly  different  quantities.  The  remaining ASVs are present in much smaller numbers  and  do  not  repeat  from  farm  to farm.  These  sequences  probably  belong  to local populations of subspecies Cryptosporidium scrofarum.  It  is  interesting  to  find  a unique sequence of the genus Cryptosporidium  of  type  ASV8,  which  can  later  be  described as a new species.

It is known that the gut microbiota plays a central role in the health and biology of the animal, and is therefore important for scientific research. Microorganisms of the genus Lactobacllus  are  widespread  in  nature  and are considered representatives of the microflora  of  the  macroorganism  of  the  animal. Lactobacllus acidophilus is widely used as a probiotic, and is known for its immunostimulating effect, it colonizes the intestines of a newborn  and  accompanies  the  animal throughout its life. Enterococcus faecium is also used as a probiotic, due to its high antagonistic activity against pathogenic microbiota, and also participates in the formation and maintenance of immunity. The purpose of  this  study  was  to  evaluate  the  probiotic component of L. acidophilus 13, E. faecium k-50  in  conditions  simulating  the  gastrointestinal tract, to study the bacteriocinogenic potential and antagonistic properties of lactobacilli and enterococci and their composition.  In  this  review,  we  summarize  recent advances  in  understanding  the  mechanisms involved in bacterial tolerance to bile, with particular  emphasis  on  research  contributions. In addition, the physiological and ecological role of enzymes and their importance for animal health, as well as the function of bile  acid  as  a  regulator  of metabolism,  are discussed. Samples were used in the study.

Escherichia  coli  are  components  of  the noromoflora  of  the  gastrointestinal  tract  of animals  and  humans,  however,  the  E.  coli genome  may  contain  genes  encoding  virulence  factors,  causing  diseases  of  animals and humans with a wide range of pathological changes and clinical manifestations. The presence or absence of virulence factors does not  always  correlate  with  the  serological group,  which  is  not  always  taken  into  account by laboratory specialists and leads to errors in diagnosis. According to the location of  the  pathological  process  caused,  escherichiosis pathogens are divided into diarrheal (DEC)  and  disease-causing  extra-intestinal localization (ExPEC). According to the presence  of  specific  virulence  factors  and  the pathogenesis of the diseases caused, diarrhe-ogenic E. coli are divided into enteropathogenic (HERES), enteroinvasive (EIEC), diffuse-adhesive  (DAEC),  enteroaggregative (EAggEC), enterotoxigenic (ETES) and shigatoxin-producing  or  enterohemorrhagic (ENES or STEC). The last three groups include  E.coli,  which  can  cause  diseases  in productive  animals.  To  E.  The  coli  of  the EXP group  include uropathogenic  (UPEC), which cause neonatal meningitis and sepsis (NMEC,  SEPEC)  and  airborne  pathogenic (ARES),  which  cause  colibacteriosis  in birds.  The  main  factor  in  the  virulence  of ENES is the production of shiga, a toxin that causes  severe  changes  in  the  body.  In  humans,  ENES  cause  hemocolitis,  often  with the  development  of  hemolytic-uremic  syndrome  (HUS),  leading  to  disability  and sometimes death of the patient. Cattle are the reservoir  of  ENES,  clinical  signs  develop only in young animals, adult animals can be carriers of ENES and contaminate milk and meat with strains. These are potential pathogens of Escherichia coli in calves and piglets. The ARES group is represented by E. coli  strains  that  cause  infection  in  poultry, especially broilers, with a variety of pathological  manifestations:  septicemia,  peritonitis, perigepatitis, air bag infections, osteomyelitis.

The aim of the work was to assess the effectiveness  of  an  improved  monitoring program  for  controlled  infectious  animal diseases  and  individual  vaccination  programs for acute respiratory viral infection in cattle.  To  fulfill  the  tasks  set,  serological studies, PCR diagnostics, bacteriological and coprological methods of examining biological samples from animals were carried out. As a result of the work, the main factors influencing  the  effectiveness  of  vaccine prophylaxis of acute respiratory viral infection in cattle populations have been identified. It was found that in three administrative and  administrative  districts  of  the  Sverdlovsk region, the main factors in 35.1% of cases are violations of the rules of vaccination  of  acute  respiratory  viral  infection  of cattle, in 13.5% of cases - violations of zoo-hygienic  and  veterinary–sanitary  conditions of keeping farm animals. A comprehensive assessment of the effectiveness of individual vaccination programs for cattle against acute respiratory  viral  infection  has  been  carried out, taking into account the epizootological situation in agricultural organizations. It was shown  that  vaccination  of  cattle  against acute respiratory viral infection according to individual  programs  ensured  the  formation of specific immunity in 92.5-95.0% of animals.  The  number  of  immunotolerant  individuals and animals with a low level of immunoreactivity in the physiological group of young  cattle  did  not  exceed  3.5%,  in  the physiological  group  of  adult  animals  – 1.25%.    The  high  efficiency  of  improved scientifically based programs for monitoring, diagnosis, therapeutic, preventive and health measures  to  protect  animals  from  epizootically significant infectious diseases of cattle among  the  populations  of  farm  animals  of the Ural Federal District has been confirmed.

The  Murmansk  region  is  an  important part of the Russian Arctic Zone, and reindeer husbandry there is one of the leading branches  of  agriculture,  which  employs  the  local population, including indigenous peoples of the North. The success of domestic reindeer husbandry largely depends on the health of the reindeer. Since the previous fundamental study of reindeer infestation with helminths was  carried  out  by  Soviet  scientists  in  the mid-twentieth  century,  there  is  an  urgent need to revise the helminth fauna. Therefore, the aim of our work was to study the biodiversity of helminths of domestic reindeer in the Murmansk region. The study of 31 fresh samples  of  domestic  reindeer  (Rangifer tarandus) feces was carried out using complex helminthoscopy methods in accordance with  GOST  R  54627-2011  “Agricultural ruminant  animals.  Methods  of  laboratory helminthology  diagnostics”:   examination, larvoscopy  according  to  Vajda,  flotation ovoscopy  according  to  Darling,  sedimentation ovoscopy using the method of successive washings, cultivation of parasitic nematode larvae from their eggs.  The intensity of invasion  was  determined  using  a  VIGIS camera from the “Diapar” kit. Helminths of two  classes  were  discovered:  trematodes  – the genus Paramphistomum and nematodes – the order Strongylida (in particular, the genus Ostertagia), the genus Dictyocaulus and the  species  Elaphostrongylus  rangiferi.  Prevalence rates were: 26% for Paramphistomum,  19%  for  strongylids,  3%  for  Dictyocaulus and 52% for E. rangiferi.  Helminths were found both on their own and in associations:  dictyocaulus  +  strongylids  +  paramphistoms,  elaphostrongylids  +  strongylids, elaphostrongylids + paramphistoms.  Among the normal larvae of E. rangiferi, there were deformed  individuals:  with  pathological swellings  in  different  parts of  their  bodies. The  intensity  of  invasion  in  all  cases  was low.

This problem is also relevant for urbanized  cases,  especially  for  the  southern  regions of the country, where there are cases of spread of ticks. Research on the basis of the Department  of  Parasitology  and  Veterinary and Sanitary Expertise, Anatomy and Pathology named after prof. S. N. Nikolsky and the Scientific, Diagnostic and Treatment Veterinary Center of the FGBOU HE "Stavropol State Agrarian University", as well as on the basis  of  the  veterinary  clinic  IP  Zaichenko "Veterinary  Center  named  after.  Pirogov. The object of the study was ixodid ticks of the genera Dermacentor and Ixodes, seized using  a  specialized  trap,  as  well  as  seized with  dogs  in  veterinary  clinics  during  the acceptance. The study showed that two main types of ixodid ticks are widespread in the city  of  Stavropol:  Demacentor  and  Ixodes. According to the results of research in 2022, female ticks of the genus Dermacentor identified  54%  of  the  total  number  of  adults, males - 46%. Female ticks of the genus Ixodes accounted for 61% of the total number of adults, males - 39%. The spring peak of activity in 2023 showed that female ticks of the genus Dermacentor were identified in the amount of 102 individuals, males - 78 individuals.  Female  ticks  of  the  genus  Ixodes accounted  for  53%  of  the  total  number  of adults, males - 47%. Thus, it has been established that the most widespread distribution of ixodid ticks takes place in the Industrial District of Stavropol, the distribution of alleys, forest zones and walking areas with the coverage of the species of ticks of the genus Dermacentor, is 79% of the total number of captured ectoparasites.

An  experimental  study  of  the  effect  of various  feed  additives  on  the  rate  of  mass accumulation,  growth  rate  and  survival  of sterlet larvae was carried out. Four groups of fish  were  planted  in  flowthrough  plastic pools with 150 fish each. The control group (I) was fed without additives, while the experimental group was fed with the addition of  different  preparations:  II -  preparation "AQUATAN"  based  on  ellagotannins  produced  by  the  company  "Tanin",  Sevnica, Slovenia. Sevnica (Slovenia) at the rate of 2 g/kg  of  feed,  III - antibacterial  preparation based on ciprofloxacin "Antibak-100" (LLC "NVTs Agrovetzaschita"), at the rate of 0.5 g/kg live weight of fish, IV - probiotic based on  Bacillus  subtilis  "SUB-PRO"  (LLC "Vector-Euro")  at  the  rate  of  100  g/t  feed. The preparations were added to the feed according  to  the  instructions.  The  effect  of preparations on fish was evaluated by fishery indicators: average daily growth rate, absolute  growth,  average  daily  gain  and  mass accumulation coefficient. During the experiment it was found that the values of fishery indicators  in  different  groups  of  sterlet changed  with  different  intensity  depending on the time after the beginning of the experiment. The highest growth rate and mass accumulation  rates  were  recorded  in  fish  fed with  SUB-PRO  and  Antibak-100,  and  the lowest  with  Aquatan.  The  results  obtained indicate the expediency of further studies of the effect of various preparations on the fishery parameters of aquaculture objects aquaculture.

The  paper  presents  the  results  of  the assessment of morphological changes in the uterus  and  ovaries  of  laboratory  animals against the background of the introduction of therapeutic doses of a multifunctional phytopreparation, which includes alcohol extracts from  plants:  white  hellebore  (Veratrum  album),  dioecious  nettle  (Urtica  dioica),  yarrow  (Millefolii  herba)  and  has  rumination, uterotonic, hemostatic and anti-inflammatory effects.  Therapeutic  doses  for  cows  were tested, which for rats amounted to 0.2 ml per head.  The  phytopreparation  was  adminitered subcutaneously three times, every other day. The control group rats were subcutaneously injected with a saline solution of sodium  chloride  (NaCI  0.9%)  according  to  the same  scheme.  The  methods  of  digital  microscopy were used  in the  study of micropreparations.  Morphometric  analysis  of  the histoarchitectonics  of  the  uterus  revealed  a statistically significant increase in the diameter of the cross-section of the uterus of female  rats  of  the  experimental  group  by 25.8%  (p≤0.05) compared  with  the  control group due to an increase in the epithelial by 24.5% (p≤0.05) and the endometrial lamina of  the  uterine  mucosa  by  32%  (p≤0.05), which indicates on increasing the secretory activity of the epithelial cover of the uterus. In  the  experimental  group  of  rats  treated with phytopreparation, a significant increase of 46% (p<0.05) in the number of primordial follicles was noted. There was also a tendency to increase the number of primary – by 36.3%, secondary – by 41.7%, tertiary – by 75%  of  follicles  and  yellow  bodies –  by 22.2%  in  rats  of  the  experimental  group compared with the control indicators.  Quantitative indicators of the follicular composition of the ovaries of rats of the experimental group and an increase in  the follicle aging coefficient by 60% (p≤0.05) indicate stimulation  of  the  ovarian  reserve  against  the background of the use of phytopreparation.

A  study  was  carried  out  to  investigate the  bioequivalence  of  the  drugs  "Doxitron chewable tablets" and "Ronaxan" when administered to dogs. Two groups of animals were formed with 4 dogs in each group. A cross-sectional study design was used for the experiment. Biological material (blood) was sampled before drug administration, and 15, 30, 45 min, 1, 1.5, 2, 3, 4, 6, 8, 8, 10, 24, 30, 48, 72  h  after  drug  administration.  In  the course of the study the following parameters were controlled: concentrations of the active substance  of  the  preparations  in  the  blood plasma of dogs. The article describes in detail the scheme of the experiment, reagents and standard samples, the process of sample preparation  of  blood  plasma  samples  and HPLC-MS/MS analysis. The bioequivalence of the preparations "Doxitron chewable tablets" and "Ronaxan" is evaluated. The time to reach the maximum plasma concentration (T_max) averaged 3.0 h for the investigational drug "Doxitron chewable tablets" and 3.0 h for the reference drug "Ronaxan". The maximum  plasma  concentration  (C_max)  was 4007.4±964.4 ng/ml for the study drug Doxitron  Chewable  Tablets  and  3794.9±1121.5 ng/ml for the reference drug Ronaxan. The 90% confidence intervals of C_maxT/C_maxR  and  AUC_0-tT/AUC_0-tR ratios of doxycycline were within the range of 80-125%. The preparations  "Doxitron  chewable  tablets"  and "Ronaxan" are bioequivalent.

Hepatotoxicants are a variety of chemical substances that can have organ-specific damaging  effects,  which  may  be  the  result  of their direct effects on both hepatocytes and other structural units of the liver. The purpose of this study is to evaluate the effect of modern hepatotoxicants on caffeine elimination. The studies were carried out in the vivarium of the Department of Pharmacology and Toxicology of the Federal State Budgetary Educational Institution of Higher Education  of  St.  Petersburg  State  University  of Medicine. Industrial substances of different chemical  groups  have  been  used  to  induce hepatotoxic  conditions:  phthalic  anhydride, ethylenediamine and chloroform. All of the above  toxicants  were  given  in  dosages  for the immediate (within 24 hours) induction of hepatotoxic  conditions.  One  day  after  the completion  of  the  simulation,  the  levels  of caffeine  in  the  blood  serum  of  the  experimental animals were determined in full accordance with the previous series of experiments, using a dosage of 100 mg/kg, since with this dosage regimen  we identified  the most stable pharmacokinetic profiles of caffeine.  Mathematical  and  statistical  processing of the obtained data was carried out using  the  STATISTICA  6.1  program.  The arithmetic mean (M) and its mean error (m) were calculated; the significance of the difference (p) was not calculated using the Student's test due to the  exploratory nature of the study and the lack of comparison groups. Based  on  the  conducted  research,  we  can conclude that each hepatotoxicant has individual  characteristic  characteristics,  which allows us to recommend a caffeine test for different types of hepatotoxicity, incl. unexpressed. That is, in this way it is possible to diagnose  hepatotoxic  conditions  even  in  a latent form, which can be used as a method for  assessing  the  toxicity  of  a  drug  at  the stage of preclinical development.

Violation of the functioning of the organs of the immune system, both in humans and in animals, is due to the influence of unfavorable factors of natural and anthropogenic origin on the body, as well as infectious diseases of various etiologies. The article discusses changes in the architectonics  of parenchymal organs of white laboratory rats after exposure to the drug interferon lambda on  the  background  of  cyclophosphamide (CF). It was found that modeling of immunosuppression through the use of CF led to a decrease  in  the  number  of  lymphoid  cells and the appearance of foci of accumulation of  blast  cells  and  megakaryocytes,  which indicates a lesion of lymphoid and hematopoietic tissues. In addition, an immunosuppressive effect on the spleen was revealed, the mass coefficient of which in the group with the use of CF was increased 3.53 times, in the group with the simultaneous use of CF and the drug interferon lambda – 2.75 times relative to the control group.  There was also a decrease in the mass coefficient of the thymus  by  47.6-50.0%  in  the  same  groups, which can be regarded as damage to the organs  of  the  immune  system.  The negative effect of CF on the spleen was confirmed by histological examination. Thus, when inducing immunosuppression, the loss of  white pulp was 73.0-77.5% relative to the group of control animals, which is 20.0% higher than in rats treated with interferon lambda, which may indicate a positive immunotropic effect of the drug under study. In addition, no significant morphological changes were detected  when  the  body  of  healthy  rats  was  exposed  to  interferon  lambda  in  the  studied organs, the morphological picture is similar to that of intact animals, which may indicate the safety of its use to animals.

The  use  of  large  doses  of  oxytocin  to sows in the early postpartum period is indicated  to  normalize  lactogenesis,  increase immune proteins in colostrum and transitional  milk,  prevent  postpartum  complications, and  increase  the  viability  of  the  offspring. However, the effect of these doses of myotropic drug on the contractile activity of the uterus  is  not  shown.  The  aim  of  the  work was to study the contractile function of the uterus of highly productive sows in the early postpartum period and the peculiarities of its reaction to supraphysiological doses of oxytocin.  Scientific  and  production  experience was carried out on the basis of a large pig breeding  complex.  The  object  of  the  study was  highly  productive  sows  16 hours  after the completion of normal labor. The hormonal  drug  oxytocin  was  administered  intra-muscularly to animals at a supraphysiological dose of 75 units. Hysterograms of uterine contractions were recorded by internal hysterography  before  and  immediately  after administration of the myotropic drug, as well as one hour after injection. On hysterograms, spontaneous contractile activity of the uterus in highly productive sows was characterized by  regular,  short-term  contractions  of  the optimal amplitude. Activation of the contractile function of the myometrium occurs 5-7 minutes  after  injection  of  the  drug.  After administration of oxytocin, an increase in the amplitude  of  contraction  of  uterine  smooth muscle cells was noted by 39.17% (p<0.05), while  a  longer  period  of  contractions  was recorded by 31.64%. The frequency of uterine  contractions  increased  2.0  times (p<0.01). The contract index was significantly  3.66  times  (p<0.05)  higher  than  that  in relation to the initial level. After 1 hour after oxytocin  administration,  an  increase  in  the contraction period by 5.42% was noted, with a decrease in amplitude by 37.87% (p<0.01) and the number of contractions by 49.91% (p<0.01),  the  contractional  index  decreased by 3.05 times (p<0.01) relative to the previous level. In relation to the initial level, the contract  index  was  20.0%  higher.  At  the same  time,  an  increase  in  the  duration  of contractions  by  38.78%  and  a  decrease  in their amplitude by 13.53% were noted. Consequently, oxytocin at a dose of 75 ME not violate the contractile ability of the myometrium.  The  response  of  the  smooth  muscle cells of the uterus to the supraphysiological dose of oxytocin is maximally manifested in the first hour after the administration of the myotropic drug.

Liver pathologies play a significant role in changing the metabolism and clearance of a  number  of  pharmacologically  active  substances,  including  1,3,7-trimethylxanthine, which is explained by their influence on enzyme systems that regulate the biotransformation of exogenous biologically active substances. Currently, changes in caffeine clearance  are  being  actively  studied  in  various hepatobiliary disorders, especially those that are chronic, since it is precisely such pathologies, according to a number of researchers, that are characterized by the most predictable  and  stable  change  in  the  trimethylxanthine  pharmacokinetic  profile.  The  purpose of  the  study  was  to  determine  changes  in serum  caffeine  levels  when  inducing  fatty liver  disease  in  laboratory  animals  (rats). The studies were carried out in the vivarium of  the  Department  of  Pharmacology  and Toxicology  of  the  Federal  State  Budgetary Educational Institution of Higher Education of St. Petersburg State University of Medicine.  Laboratory  animals  from  a  previous series of experiments were selected for the study  in  order  to  further  compare  the “caffeine curves.” Fatty hepatosis was modeled using strontium sulfate according to the methodology  developed  at  the  Department of  Pharmacology  and  Toxicology.  Upon completion of induction, fatty hepatosis was confirmed based on clinical and biochemical signs.  Based  on  the  studies  conducted,  we can conclude that there are certain correlations.  For  example,  in  fatty  hepatosis,  the elimination  of  caffeine  is  not  significantly slowed down with a characteristic long plateau (up to 8 hours after administration), turning into a smooth decrease in concentration. Experimental  data  can  be  used  to  create  a database to assess the relationship between pharmacokinetics and the physiological state of animals. Similar experiments need to be carried out on other animal species, which will create a holistic picture and help in assessing  pathologies  for  veterinary  specialists.

The purpose of the research is to study the  effectiveness  of  the  drug  ExpressTabs tested on dogs infected with helminths. The drug  contains  spinosad,  praziquantel  and moxidectin as active ingredients. Animals of mixed  breeds  of  both  sexes  aged  from  7 months to 2 years were selected for the experiments. Experimental and control groups of dogs with toxocariasis, toxascariasis and dipylidiasis  were  formed.  ExpressTabs was administered  to  dogs  individually,  once, orally in a mixture with food or immediately after feeding (on  the  root  of  the  tongue or with a treat) in a minimum dose of 30 mg of spinosad, 0.2 mg of moxidectin and 5 mg of praziquantel per 1 kg of animal weight. Animals  in  the  control  groups  were  not  given tablets. A control examination in the case of dipylidiasis  was  carried  out  on  the  second day then if the animal continued to remain in the  hospital  once  a  week.  For  toxocariasis and toxascariasis fecal examination was carried out on day 7 then on days 14, 21 and 28. The drug ExpressTabs showed high (100%) effectiveness  in  the  treatment  of dogs with toxocariasis,  toxaccariasis  and  dipylidiasis. In one animal re-infection with toxocariasis was  observed  because  helminth  eggs  were again  detected  on  day  28  in  the  control study. Taking into account the development cycle  of  parasites  it  is  obvious  that  re-infection occurred no later than a week after the  experimental  deworming  with  ExpressTabs. At recommended doses the drug did not cause unwanted side effects.

In conditions of industrial milk production, it is important to provide livestock with complete  feed,  including  all  the  necessary nutrients  to  meet  the  needs  of  a  lactating cow. Active metabolic processes and intense activity of the cow’s entire body during lactation  are  a  prerequisite  for  increasing  its need  for  vitamins.  Currently,  various  feed additives and premixes are used in feeding dairy cows, enriching the animals’ diet with essential vitamins, but their productive effect is  contradictory.  The  conducted  studies  established the positive effect of the liposomal additive “LipoCar” on meeting the need for β-carotene  and  vitamin  A  in  the  body  of cows  during  lactation.  Introduction  of  the feed additive “LipoCar” into the main diet in the amount of 6 g/cow/day. helps normalize the  vitamin  nutrition  of  cows,  especially during the transit period. This is confirmed by the results of studies of the blood serum of cows before and after the use of the LipoCar feed additive. In the control group, the content of vitamin A in the blood serum of cows was 2.4 times higher and corresponded to the physiological norm, compared to the control  group,  where  this  indicator  did  not correspond to the norm. There was a positive trend  in  the  content  of  β-carotene  in  the blood  serum  of  cows  in  the  experimental group, with an increase of 4.4 times by the end  of  the  study  compared  to  the  control group. The results obtained allow us to recommend the use of the LipoCar feed additive in the diets of cows from the first day after  calving  in  an  amount  of  6  g/head.  1 time per day for 30 days to normalize metabolism  and  increase  resistance  in  lactating cow.

Poultry  farming  is  one of  the  most  important  and  promising  branches  of  animal husbandry. Given the increasing rate of industrial poultry farming, for the stable development of the industry and improving competitiveness  in  world  markets,  more  and more attention is paid to the search for safe alternative  agents  to  increase  productivity. The study examined the strategy of feeding substances of different nature as feed additives, in particular, enzyme complexes separately  (group  I  (0,05%;  endo-1,4-beta-xylanase - 4000 units/g, alpha-amylase - 400 units/g and subtilisin - 8000 units/g)) and in combination with ultradispersed zinc (group II  (3  mg/kg;  164±31,2  nm)).  It  was  found that  in  group  I  the  digestibility  ratios  of crude  protein  were  higher  by  6.03  % (P≤0.05), crude  fiber  by  3.68  %  (P≤0.05), nitrogen-free  extractive  substances  by  2.39 %  (P≤0.05) compared  to  control.  At  the same time, in group II, changes were recorded in crude protein and crude fiber - an increase  of  6.51%  (P≤0.01)  and  7.59% (P≤0.05), respectively.  At  42  days  of  age, the  live  weight  of  broiler  chickens  I  was 10.1% higher than control (P≤0.05), and in group II by 11.32% (P≤0.01). At the same time, the cost of feed per 1 kg of growth was minimal in group II, 16.79% lower than the control values. Thus, the maximum productive effect was observed with the introduction  of  a  complex  enzyme  supplement  in combination  with  zinc  in  ultradispersed form.

Ant-decapitating  flies  (lat.  Megaselia scalaris (Loew)) is a quarantine object in the Russian  Federation  and  is  included  in  the Single list of quarantine objects of the Eurasian  Economic  Union,  approved  by  the  of the Council of the Eurasian Economic Commission dated 30.11.2016 No. 158, because it is a vector of dangerous diseases that cause great  economic  damage.  The  range  covers large areas of North America, Africa, southern  Europe,  Australia,  Southeast  Asia,  as well as the European part of Russia, namely the Southern Federal District and the Republic of Crimea. The list of regulated products subject  to  research  to  identify M.  scalaris (Loew) is very extensive, and accurate identification to species of the received samples by entomological method by morphological features of copulatory organs is very labor-intensive and not accurate. Therefore, methods of molecular diagnostics were developed for identification, namely, comparison of the studied  nucleotide  sequence with  the  reference one using NCBI database and determination of genetic distances. The studies were carried out on the basis of the Department of Molecular Research of the North-West Testing Laboratory of FGBU «ARRIAH».  Six samples of the genus Megaselia were used in this work. At the first stage, DNA was isolated  using  DNA-Extran  2  kits.  Then  genetic markers  were  obtained  by  classical  PCR with subsequent detection by electrophoresis using the T100 Thermal Cycler, sequenced on  a  3500  Genetic  Analyzer.  Identification was  performed  by  comparing  the  obtained sequence  in  BioEdit  program  using  NCBI database and by calculating genetic distances using two-parameter Kimura model and Tajima-Nei  model.  The  study  revealed  advantages and disadvantages of the presented methods of molecular identification.

The  development  of  the  agro–industrial complex of the Russian Federation is one of the priorities in agriculture. Pig breeding is one of the most profitable branches of animal husbandry. This is due to the fact that pigs  have  a  number  of  biological  features that are successfully used to produce products (pork, bacon, bacon). With the intensification  of  pig  breeding,  special  attention  is paid  to  scientific  approaches  to  improving pig feeding. In this regard, we set ourselves the goal of the study – to study the arterial vascularization of the stomach in Yorkshire piglets  and  to  determine  the  morphometric data of the organ at the stages of postnatal ontogenesis. The study was conducted at the Department  of  Animal  Anatomy  of  the  St. Petersburg  State  University  of  Veterinary Medicine.  Cadaver  material  for  the  study was delivered to the Department of Animal Anatomy of the St. Petersburg State University  of  Veterinary  Medicine  from  the  Idavang Agro pig breeding complex in Nurma village, Tosnensky district of the Leningrad Region.  The  study  was  conducted  in  three age groups, according to the periodization of the life of pigs. To achieve this task, traditional morphological research methods were used,  namely:  fine  anatomical  dissection, photographing,  vasorentgenography  with morphometry  in  the  "RadiAnt"  program. During the study, it was found that arterial gastric  vascularization  in  Yorkshire  piglets at the stages of postnatal ontogenesis is carried out due to the hepatic and splenic arteries,  which  are  branches  of  the  abdominal artery.  The  branches  of  the  arteries  of  the first order branch in a loose type. When conducting a comparative analysis of the morphometric characteristics of the hepatic and splenic arteries and their branches, we came to  the  conclusion  that  the  diameter  of  the hepatic artery will prevail over the splenic, and their branches of the first order are diametrically opposed to each other.

Increasing the productivity of cows in the modern world is a key aspect of animal husbandry.  Embryo  transplantation  in  cows makes it possible to increase the production of genetically valuable animals and improve the breeding qualities of the herd. One of the methods  for  determining  the  activity  and reserve of the ovaries is the determination of anti-Muller  hormone  in  the  blood.  AMH plays an important role in the regulation of reproductive  function  in  animals,  including cows. High levels of AMH may indicate a good reserve capacity of the ovaries, which may  be  useful  when  choosing  animals  for breeding.  In  the  presented  study,  the  bio-chemical parameters of the blood of 9 Holstein cows in the luteal phase were analyzed. A direct correlation of a high degree (0.89 and  0.89,  respectively)  was  found  between the AMH level indicator and urea and urea nitrogen  indicators.  There was  a direct noticeable correlation between the AMH level and the serum creatinine level (0.63). Also, when  assessing  the  indicators  of  mineral metabolism,  strong  correlations  were  revealed:  negative  when  comparing  the  level of  AMH  with  the  level  of  calcium  (-0.71) and  positive  when  comparing  the  level  of AMH  with  the  level  of  phosphorus  (0.78). The regulation of the synthesis of AMH itself and its metabolic effects have been studied little, there is only a limited amount of data on the relationship of the hormone with other factors of autocrine and paracrine regulation. For a more accurate understanding of this correlation and its significance, additional research is needed.

The tactics of periodic monitoring of the hematology of sows allows timely measures to prevent anemia, which inevitably occurs, since the targeted screening and selection of industrial  breeds  are  aimed  at  multiple births,  which  increases  the  risks of  anemia during pregnancy and suckling period. With periodic and constant monitoring, it is possible to deduce individual reference intervals of  hematological  indicators  for  a  particular animal and control the response to compensatory measures that directly affects the yield of viable piglets and their survival rate. The purpose of this study was to study the number  of  red  blood  cells,  hemoglobin  level, hematocrit,  average  volume  of  red  blood cells  and  erythrocyte  indices  depending  on the production cycle of the sow. The groups were formed from sows on the 80th day of pregnancy  (group  1,  n=5),  after  farrowing (group  2,  n=5)  and  before  weaning  piglets (group  3, n=5). The  Vet ABCTM analyzer (Horiba Medical Poland) was used. Counting of reticulocytes by “supravital staining” with a solution of “brilliant cresyl blue”. Statistical  processing  in  the  Microsoft  Excel  program (Data Analysis package), evaluation of the  reliability  of  differences  based  on  the Mann—Whitney U criterion. As a result, it was  found  that  the  average  volume  of  red blood cells increases with a decrease in their number  and  hemoglobin  concentration, which is quite natural and indicates a regenerative response with the appearance of reticulocytes in the blood. The correlation coefficient between erythrocytes and the average  volume  of  erythrocytes  was  r=-0.53 (r²=0.28, p=0.01), between the average volume  of  erythrocytes  and  reticulocytes  r=-0.50 (r²=0.25, p=0.05). There were no significant differences among the groups in reticulocytes and the average volume of erythrocytes. The dynamics and intensity of regeneration are moderate in all three groups.

Rainbow  trout  (Parasalmo  mykiss)  is  a promising  type  of  aquaculture  with  one  of the  largest  production  potentials  in  Russia. The  Republic  of  Karelia  currently  holds  a leading position in cage trout farming, supplying more than 80% of commercial trout produced  in  the  Russian  Federation  to  the domestic  market.  Increasing  the  output  of aquaculture products is an important condition  for  supporting  Russia's  food  security and  ensuring  the  socio-economic  development of the regions. Given the rate of spread of  diseases  in  trout,  the  rapid  change  of phases  of  the  immune  response  in  fish,  as well as the location of farms in sparsely populated remote areas, research remains particularly  relevant  on  the  search  for  sensitive molecular  methods  of  rapid  diagnosis  that identify the pathogen in the early stages of the  infectious  process  to  develop  rational treatment  and  prevention  tactics.  The  purpose of the presented study was to monitor the condition of rainbow trout in ontogenesis based on hematological studies. During the study, significant (P<0.05) differences were noted in the number of red blood cells and the total number of white blood cells (TLC), depending on the sex of the fish. In addition, clearly  distinguishable  morphometric  features  were  also  seen  among  erythrocytes, leukocytes  (lymphocytes,  neutrophils  and monocytes)  and  platelets.  Thus,  during  the monitoring of the physiological state of rainbow trout in aquaculture conditions, it was found  that  the  condition  of  the  fish  body worsens with age, which affects the morphological parameters of the blood. The hemoglobin content varied widely. A decrease in its  concentration  indicates  acute  blood  loss and hemolytic anemia. The results obtained are  the  basis  for  the  development  of  new promising natural adaptogens that normalize the physiological state of fish and ensure the production of biosafety trout products.

Taking into account the diet of the common hedgehog, we were faced with the question  of  the  features  of  the  structure  of  the chewing  apparatus  of  the  common  hedge-hogs. We decided to study and establish anatomical, topographic and morphometric features of the structure of the lower jaw in the common  hedgehog.  The  purpose  of  our study  is  to  study  the  anatomical  and  topographic features of the structure of the lower jaw  of  the  common  hedgehog  associated with the type of nutrition, as well as to establish  morphometric  data  of  the  mandibular apparatus. To study the anatomical and topographic features of the structure of the mandibular bone of this individual, five corpses of the common hedgehog from the forestry of the Leningrad region were obtained. All representatives of this species were sexually mature. As a result of our research, we have established anatomical and topographic features of the structure of the lower jaw of the common hedgehog associated with the type of  nutrition,  and  also  determined  the  morphometric data of the mandibular apparatus. According  to  the  results  of  the  study,  we came  to  the  conclusion  that  the  common hedgehog  has  a  very  powerful  and  well-developed  lower  jaw,  which  consists  of  a body and a branch. The root part of the mandibular  bone  is  2.10  times  longer  than  the incisor  part,  and  they  are  almost  equal  in width.  This  fact  indicates  the  compression power of both incisor and molar teeth during biting and chewing solid food. On the incisor part there are incisor teeth in the amount of four pieces, on the root part of the body there are molars and premolars in the form of molars and premolars with a total of four pieces.  Thanks  to  this,  hedgehogs  are  able  to easily grab food lying on the surface of the earth  and  chew  thoroughly.  The  branch  of the lower jaw has well-developed processes, thanks to which strong joints are formed and muscles are securely attached during the act of  chewing.  On  the  lateral  surface  of  the lower  jaw  branch  there  is  a  well-defined depression  that  forms  the  pit  of  the  large masticatory  muscle,  this  certainly  indicates the presence of highly developed masticatory muscles in this animal.

The  article  presents  anatomical  features of the superficial and deep fascia, in particular on the pelvic limb of the common lynx, which are absent in the available literature. The material for the research was a sectional material - pelvic limbs (n= 6), selected from the common lynx, without external signs of pathologies  of  the  musculoskeletal  system. Methods of fine macro- and microanatomic dissection of the lynx's left pelvic limb were used. At the same time, a functional analysis of  the  studied  structures  and  skeletotopic projection  of  muscles,  fascia  and  fascial nodes  were  carried out.  Based  on  the  conducted  studies,  it  was  found  that  the  deep fascia is separated from the superficial fascia by an interfacial space filled with loose connective (or fatty) tissue. In the pelvic limb area, it is represented by the gluteal-femoral fascia, and on the lower leg it continues as the deep fascia of the lower leg. In the process of dissecting the deep fascia, we noted that  in  the  gluteal  region,  the  deep  gluteal fascia is fixed on the supracosteal ligament, in the area of the root of the tail, along the tail fold and up to the sciatic tubercle. We noted  that  the  deep  gluteal  fascia  begins from the vertebral head of the biceps femoris muscle and, in the cranial direction, covers successively the posterior, superficial gluteal and caudal part of the middle gluteus muscle. Along the way, the perimysium of the above muscles are interwoven into it, however, in the area of the iliac wing, it fuses with  the  perimysium  of  the  middle  gluteal muscle  and  then  continues  into  the  lumbar fascia. At the same time, it forms a fascial node in the maklok area. Distally, the deep gluteal fascia continues as the deep femoral fascia. The data obtained are the reference in assessing the structural and functional state of the fascial formations of the pelvic limb in the common lynx.

One of the most important trends in the development  of  modern  agriculture  is  the policy of replacing or completely replacing antibiotics and chemical antimicrobial agents in animal diets.

An  alternative  to  feed  antibiotics  is  a complex of feed additives - probiotics, prebiotics,  toxin  sorbents,  phytobiotics.  Only  a comprehensive  program  of  their  use  can effectively  replace  feed  antibiotics  in  the diets of farm animals and poultry. It is relevant  and  promising  to  use  components  of plant  origin  as  feed  additives  that  can  increase  the  productivity  of  livestock,  stimuate reproduction, and improve the consumer properties of products.

The  purpose  of  the  research  was  to search for biologically active substances  in brown algae, which are potential stimulators of  nonspecific  resistance  in  poultry.  The objects  of  research  were  fresh  algae  Fucus vesiculosus  and  Ascophyllum  nodosum, collected  by  hand  from  rocky  areas  in  the coastal zone of the White Sea (near the village of Nyukhcha, Kondostrov Island, Onega Bay) during low tide from August to October 2023. During the research, the biomass of algae Fucus vesiculosus (F. vesiculosus) and  Ascophyllum  nodosum  (A.  nodosum) was studied. In these biomassages, the content  of  crude  protein,  lipids,  moisture,  as well  as  fucoidan  polysaccharides  and  alginates in the samples was studied.

Thus,  in  the  course of the research, fucoidan  polysaccharide  was  identified  in brown algae of the White Sea (fucus vesiculosa  and  ascophyllum),  which  is  a  natural stimulator  of  a  nonspecific  immune  response,  contributing  to  an  increase  in  the number of bifidobacteria in the intestines of animals.  The  presence  of  fucoidan  in  high concentrations makes brown algae a promising  basis  for  the  production  of  veterinary drugs and feed additives.

At  the  present  stage  of  development  of dairy farming, the main task facing the industry  is  the  effective  management  of  all processes that ensure the operation of a farm with a large livestock. This task will not be achievable without the use of digital intelligent  production  control  and  management systems, tracking the health of animals and their productivity.  There  are  many  systems that integrate into production and allow you to  monitor  the  health  of  cows  on  a  dairy farm. These systems are based on the identification,  tracking  and  collection  of  information about the physiological state of animals through various sensors. However, all these  systems  are  expensive,  demanding  to maintain, often fail due to aggressive operating conditions. The article considers the possibility of using an intelligent video monitoring system to analyze the physiological state of cows and predict its changes. To substantiate the requirements for an intelligent video monitoring system of the physiological state of cows, a mathematical model of the life of productive cows in the form of a graph of states is proposed. This method graphically displays the possible states of the system and their possible transitions from state to state. Having constructed a graph of states, relying on the central probability theorem for event flows, it is possible to determine the probability and intensity of state transitions using differential equations. For the functioning of the  video  monitoring  system  for  analyzing the physiological state of cows and predicting its changes,  the proposed  mathematical model can be the basis of the system and be based on the collection and analysis of video information  about  animal  behavior.  When covering the entire territory of the animal's living space with video cameras, the intelligent video monitoring system will be able to provide  early  diagnosis  of  changes  in  the physiological state of the observed animals and  issue  a  warning,  which  will  allow  for timely therapeutic and preventive measures.

The work is devoted to the study of adaptive  features  in  the Hybrid Converter novo turkey cross in a poultry farm located in the south of the Tyumen region. The aim of the work was to investigate the adaptive abilities of the body of turkeys in a poultry farm in the Tyumen region. Research work was carried out at the Department of Anatomy and Physiology  of  the  Federal  State  Budgetary Educational Institution of Higher Education of  the  State  Agrarian  University  of  the Northern Trans-Urals and in the conditions of  the  poultry  farm  LLC  "Absolut-Agro". The object of the study was turkeys of different ages and genders of the Hybrid Converter novo cross. The studies were carried out using  generally  accepted  methods  to  study the  age-related  dynamics  of absolute  mass, body  temperature,  respiratory  rate,  and  the adaptation coefficient was calculated. Physiological indicators of temperature, respiratory rate were measured in 72 heads of broiler turkeys at the age of 21 days, 42, 64, 82, 105 and  126  ays.  Analyzing  the  obtained  data, we can say that in male turkeys, the adaptation  process  proceeds  more  evenly  and quickly  after  the  manifestation  of  sexual demorphism, as indicated by a uniform increase in absolute weight, a slight deviation from the actual weight from  the normative one and a gradual decrease in the adaptation coefficient from 1.032 at the age of 42 days to 0.987 at the age of 126 days. In females, the adaptive abilities of the body are weaker, as indicated by sharp fluctuations in the actual  weight  from  the  normative  values,  as well  as  a  sharp  increase  in  the  adaptation coefficient at 42 and 82 days.

Increasing  the  output  of  aquaculture products is an important condition for supporting food security in Russia and ensuring the  socio-economic  development  of  the  regions. One of the key factors for the sustainable functioning of trout farms is the timely and  effective  prevention  of  the  occurrence and spread of diseases in farmed fish [8,10]. The purpose of the presented study was to monitor the condition of rainbow trout based on the assessment of biochemical and morphological blood parameters in age dynamics to identify critical periods and develop an adaptogen  from  green  microalgae  for  the correction  of  metabolic  processes.  In  the presented study, the hematological status of rainbow trout was studied in the conditions of the fisheries of the Republic of Karelia. The study was conducted in the summer in 4 age groups. During the research, it was revealed that the age of trout significantly affects  the  biochemical  blood  levels  studied. As a result of the research, it was revealed that in the studied animals with age there is a significant increase in such biochemical parameters  as  ALT,  Total  protein,  albumin, and urea. Thus, during the monitoring of the biochemical  status  of  rainbow  trout  under aquaculture conditions, it was found that the condition  of  the  fish’s  body  worsens  with age,  which  is  reflected  in  the  biochemical parameters  of the blood, such as total protein, albumin, and urea. In this case, green microalgae  Chlorella  can  act  as  a  natural adaptogen  that  normalizes  blood  biochemical  parameters  due  to  the  high  content  of available carotenoids. It has been established that the pigments chlorophyll a (6.68 mg/g) and carotenoids (3.36%) accumulate in noticeable quantities in the biomass of.

This  work  is  devoted  to  studying  the effect  of  Expert  Hepatic  ready-made  diets for  adult  cats  liver  care  company  MIRATORG  on  cats  in  the  complex  therapy  of hepatopathy. An important component in the complex treatment of cats with liver diseases is the use of complete diets. The purpose of these diets is to replenish energy and nutrients to maintain the body's needs and ensure the regeneration of hepatocytes to maintain liver  function.  This  can  be  achieved  if  the diet is easily digestible and has high palatability, high energy density and modified protein  content.  In  the  course  of  the  studies, biochemical blood parameters were studied, reflecting the condition of the liver in cats, which used ready-made Expert Hepatic diets for  adult  cats’ liver  care  from  the  MIRATORG company in the complex treatment of hepatopathy.  The  study  was  conducted  on the  basis  of  the  Multifunctional  Veterinary Center "SPbGUVM" in the period from February 2022 to October 2023. The study was carried out on cats of different breeds aged 6-9 years. The study revealed that at the beginning of the experiment, all experimental animals had increased indicators characterizing the condition of the liver. At the same time,  the  activity  of  the  cytolysis  marker enzymes AlAT and AST was higher than the upper limit of the reference values for this animal species by an average of 1.5 times. A less pronounced increase in activity was observed  in  alkaline  phosphatase,  the  main marker of cholestasis. These changes corresponded to a moderate increase in the content of total bilirubin. By the end of the experiment, a significant decrease in all studied parameters was observed. The level of bilirubin and alkaline phosphatase was at the upper limit of the reference values for this animal species. The activity of aminotransferases significantly decreased, but still remained above normal.

Degenerative changes in neuromuscular structures are an irreversible process in the pathogenesis  of  age-related  changes.  These include a decrease in the proportion of muscle  tissue,  the  replacement  of  nerve  structures  with  connective  tissue  elements,  the development  of  synoptic  depression  and  a decrease in the excitability and lability of the neuromuscular  apparatus  as  a  result.    An important aspect of maintaining the quality of life of dogs older than 9 years is the prvention and  postponement  of  irreversible degenerative processes. For this purpose, the introduction of  physical  activity  into  the protocols  of  prevention  and  rehabilitation after injuries is widespread in humane medicine. However, there  is no convincing evidence base for the effectiveness of physical activity in relation to the prevention of age-related degenerative changes for animals. In the  course  of  the  work,  the  influence  of physical  activity  on  the  manifestation  of degenerative  changes  in  animals  aged  9  to 11 years was studied using an electrophysiological research method - electroneuromyography (ENMG). This technique helps to assess  the  functional  state  of  neuromuscular structures  using  a  graphical  image  (M-response curve). The obtained results show that the condition of the studied structures in the experimental group of animals according to  the  obtained  electrophysiological  data  is estimated  as  more  functionally  preserved, compared  with  the  animals  of  the  control group. This is due to the fact that kinesiotherapy has a positive effect on the metabolic  processes  occurring  at  the  cellular  and tissue levels, thereby improving microcirclation  and  innervation  of  neuromuscular structures,  and  also  has  a  restorative  effect on the entire animal body The obtained results  indisputably  indicate  the  beneficial effect of physical activity on the state of the neuromuscular system of animals.

The  heart,  as  the  central  organ  of  the cardiovascular system, also has its own arterial lines to supply blood to its wall. Currently, the vascularization of the heart in animals has  not  been  sufficiently  studied,  there  are conflicting  facts  from  various  authors  of domestic  and  foreign  origin  regarding  the types of blood supply to the heart in various species  and  breeds  of  domestic  and  wild animals, and there are also inconsistencies in the  topography  of  the  branches  of  the  left and right coronary arteries. The brown bear is a common predator in the Russian Federation,  which  can  often  be  found  in  various public institutions for keeping animals. The purpose of this study is to study the architectonics of the left coronary artery in a brown bear. To study the anatomy of the heart, the corpses  of  brown  bears  aged  three  to  five years were taken. A total of six brown bear hearts were examined. To study the vascularization of the heart of the studied animals, classical and modern anatomical techniques were  carried  out,  such  as  fine  anatomical dissection  and  the  production  of  corrosive preparations using latex. As a result of the study, it was established that the brown bear has  a  predominantly  left  coronal  type  of blood  supply,  since  in  four  individuals  the left coronary artery vascularized the area of the  paraconal  groove,  subsinus  groove  and interventricular  septum.  But  at  the  same time,  it  can  also  be  assumed  that  a  brown bear may have a uniform type of blood supply to the heart, due to the fact that in two individuals the subsinus groove was supplied with blood by the right coronary artery.

The  reproductive  function  of  birds  and the hatchability of eggs are one of the most important and determining factors in raising poultry, and depend on a number of not only genetic,  physiological,  environmental,  but also morphological factors. The main goal of this article is to identify the features of the macro- and microscopic structure of the isthmus of the oviduct in a Highsex white cross chicken. The object of the study is the oviduct of a Highsex white cross chicken at the age of 180 days. For histological examination, the material was fixed in a 10% aqueous  solution  of  neutral  formaldehyde,  followed  by  embedding  in  paraffin.  The  research materials were subjected to statistical processing using the STATISTICA 6.1 program. As a result of our research, we noted that  the  isthmus  of  the  oviduct  is  located between the albumen section and the bird's uterus and has a small diameter, representing a  narrow  strip  of  tissue  (translucent  zone) with  the  presence  of  tubular  glands.  The mucous  membrane  of  the  isthmus  is  lined with multirow ciliated epithelium. Between the  primary  folds  there  are  deep  crypts, which  with  their  base  are  embedded  deep into the lamina propria; they contain many branched  glands  that  open  into  ducts  onto the surface of the mucous membrane. In the subepithelial  layer  of  the  lamina  propria, fibers of loose connective tissue are located, tightly  surrounding  the  branched  tubular glands. The mucous membrane of the isthmus occupies 59.74% of the total thickness of  the  isthmus.  Muscular  membrane  – 29.16%.  While  the  serous  membrane  accounts for 11.1% of the total thickness of the isthmus wall. The mucous membrane of the isthmus, due to the active secretory function of the glands, is 2 times the thickness of the muscular layer.

Knowledge  of  the  structural  features  of the  pelvic  limb  skeleton  is  necessary  for  a veterinary  specialist  performing  surgical interventions on this area of the body. It is the structure of the pelvic limbs that gives the  relative  springiness  to  the  body  of  the sable  with  a  jumpy  run  and  the  speed  of movements  and  reactions  to  surrounding actions.  In  connection  with  the  above,  the relevance of this study is beyond doubt. The study  was  conducted  at  the  Department  of Animal Anatomy of the St. Petersburg State University of Veterinary Medicine. The objects for this study were the corpses of the black  Pushkin  sable  breed  of  two  age groups:  15-20  months  from  birth (physiological  maturity)  and  36-40  months from birth (puberty). To achieve this task, a complex  of  traditional  anatomical  research methods  was  used:  fine  anatomical  dissection,  maceration,  photographing  and  morphometry.  The  age-related  anatomical  features of the skeleton and morphometric data of the femur of the sable of the Black Pushkin breed in conditions of limited  mobility were  established.  Sables,  living  in  natural conditions, receive significant physical exertion  on  the  pelvic  limb.  This  explains  the decrease in the diameter of the femoral neck in animals with limited dynamics with age. Keeping these animals in the conditions of fur farms significantly reduces the level of locomotion,  which  certainly affects  the  development of bones and their structures. The patella  block  as  an  adaptive  structure  receives  significant  additional  lateroal  and proximal  development,  manifested  in  the form  of  ridges  extending  beyond  the  compact substance of the knee block. This structure of the block contributes to the maximum extension of the knee joint with the contraction of the quadriceps femoral muscle.

The paper presents the results of examine  the  relationship  between  blood  plasma incubation  temperature  and  the  hemostasis parameters in chickens. The purpose of this research was to study of the blood coagulation  parameters  in  chickens  during  hypo-, normo- and hyperthermia in vitro. In addition, to assess the possibility of using a coagulometer to identify hemostasis activity and the use of hemostatic reactions in chickens as models for human medicine. The Vologda region was where the study was conducted. The coagulogram was examined for the following parameters: thrombin time (TT), prothrombin time (PT), activated partial thromboplastin  time  (APTT),  fibrinogen  activity, and antithrombin III activity (AT-III). It was found that at 46° C activation of blood clotting occurs, manifested as an acceleration of the  TT  by  29%  (13  seconds),  PT  by  72% (111  seconds),  and  decrease  in  the  antithrombin III activity by 6% (1.5 seconds) compared to normothermia. The parameters of  secondary  hemostasis  also  responded  to hypothermia (18 °C) with hypercoagulation. It  was  an  acceleration  of  PT  of  81%  (125 sec),  an  increase  in  fibrinogen  activity  by 77% (84 sec) and a decrease in AT-III activity  by  55%  (14  sec),  with  the  exception  of thrombin time, which was extended by 70% (104  seconds).  There  were  no  significant changes  in  the  APTT  at  different  temperatures.  The  correlation-regression  and  one-factor analysis of variance revealed a significant correlation between the temperature and the TT and the fibrinogen activity, where the coefficients of determination for which were 71%  and  39%,  respectively.  Plasma  hemostasis  activity  measured  on  a  coagulometer (at 37 °C) showed no significant differences from  those  measured  at  43  °C,  except  for prothrombin time, which was 71.51 seconds (47%) less than that measured at 43 °C.

The  morphofunctional  status  of  the  digestive apparatus, including the small intestine, is decisive in the implementation of life-supporting functions both at the organ and at the organizational level, which is due not only to its participation directly in digestion, but  also  in  providing  immunogenesis  with tissue  components  of  the  intestinal  wall. However,  in  the  scientific  literature,  the structure  of  the  intestinal  wall  in  newborn quails  is  not  described  fully  enough,  there are no comparative data on the morphology of  the  small  intestine  within  the  group  of breeds belonging to the meat direction. The purpose of the study: to establish the features of the structure of the intestinal wall in diurnal quails of meat breeds. The breed features of the morphology of the small intestine of diurnal  quails  of  the  meat  breeds  Pharaoh, Texas  and  Japanese  by  n=4  were  studied using  a set of morphological techniques. It was found that the length and width of the villi prevail in the diurnal quails of the Japanese breed, as well as the number of goblet cells  in  the  duodenum  and  jejunum  compared with those of the Pharaoh and Texas quails,  while  the  smallest  values  of  the length and width of the villi, as well as the number of goblet cells, were revealed in the Pharaoh quails. The exception was the thickness of the serous membrane of the jejunum, which has the highest index in daily quails of the Pharaoh breed, and the lowest in quails of the Texas breed.

The  reindeer  is  a  representative  of  the order  artiodactyls,  most  of  the  individuals inhabit  the  territory  of  the  Northern  hemisphere. It is a significant hunting and commercial  species,  and  reindeer  husbandry  is the main branch of animal husbandry in the conditions of the Far North. The morphology of the reindeer has always been of interest to researchers. In different years, the architectonics  of  the  vascular  bed  of  the  reindeer have been  studied  by  many  researchers  [3, 4].  However,  in  the  available  literature sources, we have not found data concerning arterial blood supply to organs and tissues in reindeer  fetuses.  In  the  prenatal  period  of development, there is a restructuring of organs and tissues, and with them the vascular bed. The aim of the study was to study the arterial vascularization of the pelvic limb in a reindeer fetus, to give morphometric characteristics  to  the  arteries.  The  studies were conducted on 5 reindeer fetuses at the age of 4.0-4.5 months. The fruits were delivered to the Department of Animal Anatomy of the St. Petersburg State University of Veterinary Medicine from reindeer herding farms of the Republic of Sakha (Yakutia). The fruits were extracted after the slaughter of vazhenok for household  needs.  Classical  methods  were chosen as research methods: fine anatomical dissection, morphometry, photographing and vasorentgenography.  During  the  study,  it was found that the main arterial trunk of the pelvic limb in a reindeer fetus is the external iliac  artery.  Skeletotopy  and  angioarchitectonics of the main arteries of the pelvic limb of  the  reindeer  fetus  have  typical  patterns characteristic of adult animals. Morphometric parameters of the arteries are consistent with the topographic position of the muscle groups – a greater number of large arterial branches are noted in the hip area. The presence of collateral blood flow in the foot area is noted – the vessels of the dorsal and plantar surfaces are connected to each other due to the perforating metatarsal and perforating metatarsal arteries, as well as at the confluence of the axial and non-axial finger arteries.

The study of the lymphatic system is of interest not only for morphology, but also for physiology and pathology, since it is in the organs and tissues where the lymphatic capillaries are located that metabolism occurs. The  lymphatic  bed  is  represented  by  intramural vessels, regional lymph nodes of the first and second order. The aim of the study was to determine the lymph nodes and vessels involved in the lymph outflow from the lip area in sheep of the Edilbaev breed. The study  was  conducted  at  the  Department  of Animal Anatomy of the St. Petersburg State University of Veterinary Medicine. The material was sheep of the Edilbaevsky breed in the amount of five pieces at the age of one year. As methods, an interstitial (interstitial) injection with cotrust masses in the form of a blue  mass  of  Gerot  was  used,  which  was prepared by rubbing 2.0 g of blue oil paint in 30.0 g of gum turpentine. The resulting mass was mixed with 15.0 g of ether and passed through  a  filter.  Before  the  injection,  the sheep's head was placed in warm water for several  hours.  The  injection  is  carried  out with  a  syringe  with  thin  needles.  Contrast masses  were  injected  very  slowly,  gently massaging the injected area. As a result of our research, we came to the conclusion that the direction of the main lymphatic vessels of the upper lip and the edges of the nasal opening corresponds to the line drawn from the corner of the lips to the mandibular joint; the direction of the diverting lymphatic vessels of the lower lip corresponds to the direction of the free edge of the lower jaw; the main regional lymph nodes for the diverting lymphatic vessels of the lips of the sheep of the Edilbaev breed are the parotid and mandibular  and,  in  isolated  cases,  the  lateral pharyngeal.

Currently, artificial insemination, as one of the types of assisted reproductive technologies, is widely used in dairy and beef cattle breeding.  The  same  cannot  be  said  about such a promising direction in the agricultural industry as goat breeding. One of the limiting  factors  is  the  negative  impact  of  low temperature on the morphofunctional charateristics  of  sperm  of  breeding  goats.  The purpose of this research was to test a protocol of sperm cryopreservation of stud goats with  modification  of  prepreparation  and subsequent assessment of the quality indicators of sperm before and after its deep freezing. A comprehensive assessment of sperm quality (volume, concentration, morphology, motility)  of  goats  (n=10)  was  carried  out using generally accepted methods and protocols. The assessment of sperm quality indicators included five stages: after sperm collection, two hours after cooling, after thawing: 0 hours, 1 and 2 hours. According on the obtained results, the sperm of breeding goats ha low cryoresistance. After cryopreservation  (0,  1  and  2  hours  after  thawing), there is an increase in the number of sperm with tail damage by 7.5% (p≤0.05), 15.5% and 21.8% (p≤0.01), and also a decrease in the number of progressively moving sperm by 1.4; 1.6 and 2.5 times (p≤0.01) compared with  the  results  of  the  assessment  0  hours after collection. The use of a deep two-phase sperm freezing protocol allows maintaining the viability of sperm with a progression of movements equal to 54.2±5.1% and a number of morphologically normal sperm equal to  64.1±1.9%.  In  this  case,  the  prepreparation  of  sperm  for  the  cryopreservation  process  (current  protocol)  includes sperm  centrifugation  (mode:  7000  rpm  for 15  minutes),  removal  of  seminal  plasma, dilution  1:4  (OptiXcell  diluent),  cooling  (4 hours at 4℃); sperm cryopreservation protocol: 1. immersion of goblets with paillettes 4 cm above liquid nitrogen for 7 minutes; 2. complete immersion in liquid nitrogen.

Studies have been conducted to study the effect of the cytokine profile of cows with chronic systemic inflammation syndrome in the third trimester of pregnancy on the hematobiochemical  status  of  newborn  calves. The  experiment  was  conducted  on  redmottled  cows,  which  were  divided  into  2 groups: group 1 (n = 15) – clinically healthy cows  with  uncomplicated  pregnancy,  average fatness 3.6 ± 0.16 points, group 2 (n = 7) – cows with lowintensity chronic systemic inflammation  syndrome,  average  fatness 4.4±  0.20  points.  At  the  beginning  of  the third  trimester  of  pregnancy,  blood  serum samples were taken from cows to determine the  level  of  interleukin-1β  (IL-1β),  tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2),  interleukin-4  (IL-4),  interleukin-10  (IL-10) and interferon-γ (INF-γ). On the 3rd day after birth, blood samples were taken from the received calves for analysis. The above cytokines  and  hematobiochemical  parameters  were  determined.  It  was  found  that  in calves from group 2, the level of IL-2, IL-4, IL-10 and INF-γ was lower than the comparison group by 10.0; 29.3; 24.5 and 17.4%, respectively,  and  IL-1ß  and  TNF-α  were 45.8  and  8.7%  higher.  Spearman's  correlation analysis showed that there is a significant direct correlation of noticeable and high strength  between  the  level  of  cytokines  of maternal cows and similar indicators in newborns, which indicates the influence of signaling proteins of the mother's body on fetal development.  As  a  result,  neonatal  hepatodystrophy  was  diagnosed  in  calves  born from cows with chronic systemic inflammation  syndrome,  accompanied  by  cytolysis and  cholestasis  syndrome,  accumulation  of endotoxins  and  a  decrease  in  energy  substrates. The data obtained show that a change in  the  cytokine  profile  during  pregnancy towards  the  predominance  of  proinflammatory  cytokines  creates  a  risk  of developing  antenatal  liver  pathology  in  future offspring, thereby forming prerequisites for the development of comorbid pathology in newborns.

In  reproductive  technologies  applied  in animal husbandry, using  lyophilized semen is only possible with ICSI technology, due to complete loss sperm motility. However, the anatomical  structure’s  peculiarities  and  development  of  avian  oocyte  not  allows  use this technology. Strategies aimed at preserving  kinetic  apparatus  of  lyophilized  sperm are  the  most  relevant  for  birds.  Increasing mitochondrial activity of cells due to its connection with energy metabolism and sperm motility may be one of the ways to solve this problem. However, similar studies on freeze-dried bird semen haven’t been conducted on this  moment.  The  present  study  assessed effect  of  mitochondria-targeted  antioxidant Mito-TEMPO  on  viability,  mitochondria’s membrane potential and generation of intracellular hydrogen peroxide by rooster spermatozoa  in  a  cryopreservation  and  lyophilization cycle. Proportion of cells with intact plasma membrane in lyophilized semen was higher using extenders containing an antioxidant. Addition  of  Mito-TEMPO  at  concentration of 40 µM to diluents T-20 and T-30 for the purpose of cryopreservation of semen with  subsequent  freezedrying  allowed  to increase proportion of cells with intact plasma membrane in lyophilized semen in comparison  to  control  diluents  (6.12  ±  0.11  % versus  10.19±0.46%  and 13.19±1.30% versus  15.23±1.13%,  respectively,  p˂0.05). Effective concentration of Mito-TEMPO in diluents intended only for semen cryopreservation was significantly lower - 5 µM. Proportion of cells with intact plasma membrane was  47,97±0,64%  versus  55,85±1,69%  and 47,25±2,97%  versus  63,21±1,78%,  respectively,  p˂0,  05.  Dose-dependent  effect  of trehalose in cryoprotective diluents has been proven.

The  structural  features  of  the  plasma membranes of avian sperm make them more sensitive, compared to those of mammals, to low-temperature  stress.  The  qualitative  and quantitative composition of membrane lipids can become a determining factor in the development of new effective compositions of cryoprotective  media.  The  purpose  of  the study was to determine the lipid composition of the plasma membranes of native rooster sperm, the content of carbohydrates and polyols  in  their  cytosol,  as  well  as  dynamic changes in the membrane lipidome and cytosol  composition  under  the  influence  of  the cryopreservation protocol, depending on the composition  of  the  cryoprotective  medium. The  studies  were  carried  out  on  Rhode  Island roosters (n=10), the total and progressive sperm motility and membrane damage were determined. Semen freezing and thawing was carried out using fast protocols. To determine the lipid composition of the plasma  membranes  of sperm and  the composition of their cytosol, a chromatographic analysis method was used. The following were identified in the membranes of native spermatozoa:  phospholipids,  glycolyllipids  and neutral lipids, represented by phosphatidylethalamine,  phosphatidylserine,  phosphatidylcholine,  sphingomyelin  and  sterol.  A change in the ratio between membrane lipids of the inner and outer layers of the plasma membrane of rooster spermatozoa under the influence  of  the  cryopreservation  protocol was shown. In native spermftozoa this ratio was  41.2%  and  39.4%,  respectively,  in thawed sperm when using the LCM-control medium –  38.3% and  47.2%, respectively, when using the LCM-T20 medium - 40.7% and 44.5%, respectively. There was a significant decrease, more than 3 times, in the total amount of carbohydrates (fructose, glucose, trehalose)  and  polyols  (glycerol,  mannitol, inositol)  in  the  cytosol  of  frozen/thawed spermatozoa when using the cryoprotective medium  LCM-control  compared  with  the values of the native spermatozoa - 0 .1145 mg/ml  and  0.0360  mg/ml,  respectively. When  using  the  LCM-T20  medium,  the change was insignificant and the delta was 5.2%. The effectiveness of using cryoprotective medium LCM-T20 containing trehalose has been proven to maintain the lipid membrane  architecture  of  rooster  spermatozoa, the carbohydratepolyol composition of their cytosol and, as a consequence, the morphofunctional usefulness of gametes during the freezing/thawing process.

The  intensity  of  metabolic  processes  in highly  productive  cows  is  associated  with metabolic disorders and the development of dystrophic  changes  in  the body.  The  paper evaluates the effect of the concentration of β-hydroxybutyrate and glucose in the blood of new-bodied cows on the indicators of reproductive ability and milk productivity. To do this, venous blood was obtained from cows of different ages after childbirth, where the concentration  of  glucose  and  β-hydroxybutyrate was determined. Depending on  the  level of glucose  and  ketone  bodies, animals  were  retrospectively  differentiated into groups and the severity of economically useful  signs  was  determined.  It  was  found that  cows  with  a  glucose  level  above  3.3 mmol/l  required  0.6  more  inseminations (P≤0.01), compared  with  animals  whose indicators  were  in  the  range  of  2.2...3.3 mmol/l. At the same time, the greatest difference in the multiplicity of insemination was present in animals 3...7 lactation (1.2 inseminations per fertilization; P≤0.001). The period from calving to fertilization in cows with a high glucose content was longer by 39.4 days (P < 0.05), while the maximum deviation was found among animals older than the 2nd  lactation  (by  43.4%;  P<  0.05).  An  increase in the level of β-hydroxybutyrate over 0.7 mmol/l was also accompanied by a deterioration in reproductive function. Thus, the lengthening  of  the  infertility  period  for  all lactation was 21.2 days (P≤0.05). The most pronounced negative effect on reproductive function in ketonemia was observed in first-heifers and cows of the second lactation. So, after  the  first  birth,  the  lengthening  of  the period from calving to fertilization was 42.0 days (P < 0.05), and after the second lactation - 29.2 days (P < 0.05). Thus, an increase in  the  level  of  glucose  and  β-hydroxybutyrate in the blood negatively affects, first of all, the reproductive function of cows, and to a lesser extent, the indicators of milk productivity.

Indicators of  the blood  coagulation  system (thrombin time, prothrombin time, activated  partial  thromboplastin  time -  aPTT) were studied on 42 pregnant cows at 60-75, 135-150  and  210-230  days  of  pregnancy, divided  according  to  the  principle  of  analogues  into  three  groups:  physiological course,  fetal  growth  restriction  syndrome without  late  toxicosis  of  pregnancy,  fetal growth restriction syndrome complicated by gestosis.  Pregnancy  was  diagnosed  using transrectal  and  ultrasound  examinations. Fetal growth restriction syndrome was diagnosed at 60-75 days of pregnancy using an ultrasound scanner with a linear sensor with a  frequency  of  7.5  MHz.  Late  toxicosis  of pregnant animals was diagnosed at 210-230 days of pregnancy by the presence of hypertension, proteinuria and edema. Blood samples were taken from the animals included in the experiment to determine the platelet content,  thrombin  and  prothrombin  time  and aPTT.  It  has  been  established  that  platelet content is an informative indicator for predicting  gestosis  in  the  first  five  months  of pregnancy  with  a  sensitivity  of  80.0%  and specificity  of  87.5%.  The  sensitivity  of thrombin time at 60-150 days of pregnancy is  77.8%,  specificity -  90.0%,  prothrombin time  -  70.0  and  88.9%,  aPTT  at  135-150 days of pregnancy - 77.8 and 85.7%, respectively. Prognostic markers for early diagnosis of late toxicosis in pregnant animals, determined  at  2  months  of  pregnancy  are: platelet  level -  451.2  x  10⁹/L  and  higher; thrombin  time –  87.3 seconds  and  below; prothrombin time – 35.1 seconds and below. Indicators  for  early  diagnosis  of  gestosis, determined  at  5  months  of  pregnancy,  are: platelet  level -  437.5  x  10⁹/L  and  higher; thrombin  time –  78.6 seconds  and  below; prothrombin time – 30.3 seconds and below; aPTT – 41.8 sec and below.

In  modern  high-tech  dairy  enterprises, the problem of perinatal diseases in highly productive dairy cattle is acute. The current study presents the distribution of extracellular matrix in cows during physiological pregnancy ending in spontaneous labor (FB/SR) and complicated pregnancy with symptoms of preeclampsia/eclampsia ending in pathological  labor  (OB/PR)  using  histological, histochemical (HC) and immunohistochemical (IHC) research methods. Biopsy material of placentas was obtained from 10 cows during labor: from 5 cows with FB/SR and from 5  cows  with  OB/PR.  Samples  of  placentas from  cows  with  FB/SR  and  OB/PR  were subjected  to  standard  histological  procedures. Paraffin sections of the placenta, 5 µm thick, were mounted on glasses treated with poly-L-lysine (Menzel). Using IHC studies, the  immunolocalization  of  the  Ki-67  biomarker was studied. A histochemical study in  the  placentas  of  cows  with  FB/SR  revealed  the  presence  of  a  large  number  of small capillaries both in the villi of the cotyledons and in the caruncular crypts, as well as an equilibrium ratio of mesenchymal and epithelial  structures.  The  reaction  to  vimentin showed degradation of fibroblasts. In the  lumen  of  the  crypts,  only  structureless masses and a small number of macrophagelike cells were recorded. In addition, in the central part of the unchanged villi, a sharp decrease in the number of small capillaries was established, as well as a reduction in the terminal chorionic villi and a decrease in the vascularization of the remaining villi. Immunolocalization of the content of intermediate biomarkers  showed  the  content  of  a  large amount  of  Ki-67  in  the  cells  of  the  crypt lining. During pregnancy OB/PR, a decrease in the vascularization of chorionic villi in the cotyledons  and  degradation  of  cytokeratin filaments involved in the formation of cellular contacts between the cytotrophoblasts of the  chorionic villi  of  the  cotyledons of  the fetal part of the placenta and the epithelial cells  of  the  crypts  of  the  caruncles  of  the maternal  part  of  the  placenta  have  been demonstrated, which will make it possible in the future to develop an enzyme-linked immunosorbent assay (ELISA) as a rapid – test for  diagnosing  reproductive  pathologies  in dairy cattle. Pronounced expression of the Ki-67 protein was found in the cells lining the crypts of the caruncles, as well as in the cytoplasmic  membrane  of  the  villous  cytotrophoblasts. In the placenta of cows whose pregnancy  and  childbirth  were  complicated by pathology, the proliferative activity of the cells lining the uterine crypts remained at a physiological  level,  while  individual  chorionic  villi  were  completely  reduced,  and  in those  that  remained,  the  Ki-67  expression index was 36.94%.

One of the important factors affecting the reproductive function is the genotype of the animal. The method of genomic selection is based on the use of polymorphic single nucleotide substitutions (SNP) as markers  for determining the value of the genotype of an animal or plant. The formation and functioning  of  the  reproductive  system  of  animals occurs as a result of the coordinated interaction of a wide range of genes.  The search for genomic  associations  of  GWAS  (Genome-Wide Association Studies) with signs of fertility will allow further selection of animals based  on  these  indicators  at  the  genomic level. Sperm was obtained with the help of mares in hunting and on a phantom using an artificial  Hannover  vagina  (Minitube,  Germany). The sperm of each stallion was collected at least three times. The semen quality of 96 stallions of different breeds (Arabian, Akhal-Teke, Trakenen, thoroughbred horse, Oryol  trotter,  French  trotter,  Soviet  heavy horse, Shetland pony, Welsh pony, horses of different breeds) was analyzed. High variability  of  sperm  quality  indicators  was  revealed.  For  example,  the  concentration  of sperm in the ejaculate varied from 59 to 514 million /ml, progressive mobility from 20 to 87%, and the number of cells without damage from 21.6 to 95.6%. Such variability of the studied features makes it possible to assume that their formation in the process of ontogenesis  occurs  under  the  influence  of genetic factors. The GWAS analysis of ejaculate volume, concentration and motility of stallion  sperm  revealed  potential  candidate genes associated with these indicators. The associations identified in our study are promising candidates for further identification of the  biological  mechanisms  underlying  the quality of stallion sperm.

The purpose of this research is to study the  influence  of  mesenchymal  stem  cells from  adipose  tissue  and  bone  marrow  of goats  on  the  quality  parameters  of  their sperm. A complex evaluation of sperm quality  (volume,  concentration,  morphology, motility) of Saanen and Czech goats (n=10) at the age of 1-2.5 years was carried out according  to  generally  accepted  methods  and protocols.  Adipose  tissue  (AT)  and  bone marrow  (BM)  were  obtained  after  the slaughter of goats (n=6) on a peasant farm in the Volkhov district of the Leningrad region. After processing the obtained samples, mesenchymal stem cells obtained from adipose tissue and bone marrow of goats were isolated,  accumulated  and  cryopreserved.  Three groups of samples of 10 each were formed: control (spermatozoa 7x10¹⁰ cells/ml + PBS buffer 100 μl, pH – 7.4), first experimental (spermatozoa  7x10¹⁰  cells/ml  +  MSCs 2x10¹⁰ cells/ml, pH – 7.2), the second was experimental (sperm 7x10¹⁰ cells/ml + BM MSCs 2x10⁸ cells/ml, pH – 7.2) and a four-stage assessment of sperm quality was carried out: after incubation of sperm with mesenchymal  stem  cells  at  a  temperature  of 38℃ for 0, 1, 2 and 3 hours. Based on the results obtained, the working protocol for the use of mesenchymal stem cells from adipose tissue  and  bone  marrow  for  the  sperm  of breeding goats is the concentration of MSCs -  2x10⁸  cells/ml  and  the  concentration  of goat  spermatozoa -  7x10¹⁰  cells/ml.  The studies conducted have established the positive effect of mesenchymal stem cells from the adipose tissue and bone marrow of goats on the quality indicators of their sperm. At the  same  time,  spermatozoa  remain  viable during three-hour incubation with a progression  of  movements  equal  to  51.5±8.46  - 51.8±5.2% and a number of morphologically normal  sperm  equal  to  50.40±2.21  - 51.10±3,  14%  (3  hours  after  incubation, MSCs from adipose tissue and bone marrow, respectively).

The doctrine of the normal microflora of the human and animal body is currently in the focus of attention of clinical microbiologists and a wide range of clinical specialists. It is known that the microflora of the vagina depends on many factors of the internal and external  environment,  therefore,  it  is  now considered to be an ecosystem with a unique set of mechanisms that ensure its resistance to  foreign  microorganisms  and  support  reproductive health. The aim of the study was to study changes in vaginal microbiocenosis in cows during different periods of pregnancy.  The  object  of  the  study  was  clinically healthy cows (n=10) of a redmottled breed (holshitinized), and the subject of the study was  cervical–vaginal  mucus.  On  the  150-160, 210-220 and 260-265 days of pregnancy,  mucus  samples  were  taken  from  cows using sterile probe tampons for bacteriological studies. It was found that representatives of  the  normoflora,  as  well  as  conditionally pathogenic and pathogenic microflora were present in the vaginal secretions of animals of  all  periods  of  pregnancy.  However,  the total  bacterial  contamination  of  the  genital tract in cows in the first half and second half of the third trimester of pregnancy was characterized by its decrease by 29.2 and 33.3%, respectively, relative to the data obtained in the second trimester. It should also be noted that by the second half of the third trimester of pregnancy, there is an increase in obligate normoflora due to lacto- and bifidobacteria by 27.1% and 4 times, respectively, with the predominance of the genus Lactobacillus in quantitative terms. Against this background, the amount of transient microflora decreased by 34.2-57.1% (P0.05).

Reindeer  husbandry  is  the  leading branch of agriculture for the regions of the Far  North.  Reindeer  (Rangifer  tarandus) remains  poorly  studied  from  the  point  of view  of  genetics  and  reproduction,  which hinders the intensification of development of the industry. Research is being actively conduct in the field of genetics of the productive qualities of reindeer, but the formation and functioning  of  its  reproductive  system  has been little study. Hormonal regulation of the reproductive  process  and  the  formation  of hormonal status at key stages of the reproductive cycle is a significant aspect of animal reproduction. Reindeer are characterized by a pronounced seasonality of reproduction, and the study of hormonal regulation of the reproductive cycle is the main aspect of the further use of assisted reproductive technologies. The work is devoted to the analysis of the  level  of  anti-Mullerian  hormone  in  females during the breeding season. The studies were carried out on reindeer farms of the MAU “Directorate of the Territory of Traditional Natural Resources Management  of  Soyots”,  Buryatia,  (female, n=29). The dependence of the concentration of anti-Müllerian hormone (AMH), which is a generally accepted indicator of the female ovarian reserve, on the concentration of sex hormones  (progesterone,  estradiol,  testosterone and luteinizing hormone) in the blood serum of females was study. Hormone levels were  determined  by  enzyme  immunoassay. A higher content of sex hormones - testosterone,  estradiol,  progesterone  and  luteinizing  hormone  was  revealed  in  the  group  of women  with  an  AMH  concentration  of  >1 ng/ml than in the group of women with an AMH concentration of <1 ng/ml. The significance of the differences in progesterone was p<0.05,  and  in  estradiol – p<0.001.  A  low concentration  of  AMH  (<1  ng/ml),  characterizing a reduced ovarian reserve of female reindeer,  corresponds  to  a  reduced  concentration of sex hormones that support reproductive  function,  and,  conversely,  a  high concentration of AMH (>1 ng/ml), and, accordingly, a high ovarian reserve the reserve corresponds to an increased concentration of sex hormones - testosterone, estradiol, progesterone and luteinizing hormone.

The  article  discusses  the  results  of  a study  of  the  milk  productivity  of  cows  in connection  with  the  content  of  beta-hydroxybutyric acid in the blood during the new calving period. The studies were carried out on highly productive full-aged cows of the second and third lactation. The animals were divided into three groups according to the content of beta-hydroxybutyrate - up to 1.0 mmol/l; from 1.0 to 2.0 mmol/l and over 2.0 mmol/l. It has been established that an increase  in  the  content  of  ketones  in  the blood  is  associated  with  hypoglycemia. Cows  with  increased  levels  of  beta-hydroxybutyric acid at the beginning of lactation showed higher daily milk yields over a five-month  period  of  observation.  In  the fourth and fifth months of lactation, the milk yield  of  these  cows  was  higher  than  in groups  1  and  2  by  14.6-15.8%  and  18.5-20.1%, respectively. In addition, the total yield of fat in this group is greater than in the first and second - by 12.8% and 10.7%, protein - by 9.7% and 11.2%,  and  lactose -  by  8.5%  and  13.5%, respectively.  A  calculation  indicator  was proposed -  the  lactation  anabolism  index, which  is  calculated  using  daily  milk  yield, mass fraction of milk protein and urea concentration.  An  increase  in  this  index  indicates the activation of anabolic reactions, a decrease indicates a surge in catabolic processes.  An  increase  in  the  lactation  anabolism index  was found in  cows of the third group at 4-5 months of lactation with a significant increase of 44.8-45.8% in comparison with groups 1 and 2. A high metabolic potential for further productive lactation was established in cows that had increased concentration of beta-hydroxybutyric acid in the new calving period.

The  paper  presents  statistical  results  of identifying combinations of various congenital heart defects in dogs of different breeds diagnosed with pulmonary artery valve stenosis. The study was retrospective, conducted on the basis of the Department of General, Private and Operative Surgery, as well as in the veterinary clinic of neurology, traumatology and intensive care. The total sample  amounted  to  100  animals.  All  animals underwent a complete physical examination. The morphofunctional state of the heart was evaluated. Diagnosis was made by echocardiography  using  Doppler.  Each  congenital heart defect was evaluated and studied separately, noting its individual features and hemodynamic  changes  in  the  combination  of several congenital anomalies of heart development.  The  study  was  conducted  before performing surgical treatment of pulmonary artery valve stenosis by balloon plasty of the pulmonary artery valve. This study included animals with other cardiac anomalies in addition  to  obstructive  right  ventricular  outflow tract disease. Among 100 dogs examined, the most frequent combined heart defect was Fallot's tetrad. This pathology was singled out separately, as its mechanism of development  differs  significantly  from  a simple combination of several anomalies of heart development. It is believed that this is one heart defect consisting of several components. In addition, atrial septal defect, mitral or tricuspid valve dysplasia, open ductus arteriosus,  and  aortic  valve  stenosis  were found in combination with pulmonary valve stenosis. Combined heart defects were most common  in  French  Bulldog  dogs  in  this study, as this is the most common breed of dog diagnosed with pulmonary valve stenosis.

The article presents the results of a study on the effect of steroid and nonsteroidal anti-inflammatory drugs on platelets.

The object of the study was plasma obtained  from  rat  blood  (n=10).  Blood  sampling (2.0 ml from each animal) was carried out  from  the  tail  vein  into  test  tubes  with sodium citrate. Cell elements were counted directly in blood and in platelet plasma using a MEK-6550 hematological analyzer.

The  ability  to  influence  platelet  activation was determined in drugs such as dexamethasone,  ketarol  and  miloxicam,  which were injected into test tubes before plasma reactivation.

 It  was  found  that  the  drugs  of  these groups affect the metabolism of these cells and inhibit their ability to cause clot contraction.  It  was  found  that  the  strength  of  the negative  effect  on  clot  contraction  in  the steroid drug dexamethasone, which through intermediaries  suppresses  the  activity  of phospholipase-A2 and the nonsteroidal drug ketarol,  which  is  the  predominant  inhibitor of cyclooxygenase of the first type, are similar.  It  was  also  found  out  that  the  drug meloxicam, which is a predominant inhibitor of cyclooxygenase of the second type, causes only a slight decrease in platelet clot contraction. The results obtained in the experiment indicate  a  direct  positive  relationship  between the degree of clot contraction and the amount  of  thromboxane-A2,  which  is  synthesized and released by activated platelets. It  is  known  that  the  ability  of  platelets  to accelerate and enhance regenerative processes is also directly related to their activation. Based  on  this,  it  is  suggested  that  patients who have been  prescribed  plateletenriched plasma  therapy  should  not  use  glucocorticoids and preparations with a high degree of selectivity  to  cyclooxygenase  of  the  first type as anti-inflammatory drugs.

Comparative  studies  of  four  main  ophthalmic dyes were carried out on their ability,  after  a  single  short-term  exposure,  to stain a corneal incised wound.

12  year–old  Wistar  rats  weighing  180-220  grams  were  selected  for  the  study.  4 experimental  groups  of  3  rats  each  were formed from them. Corneal incision wounds were inflicted on all animals. A 10.0% lidocaine  solution  was  used  to  anesthetize  the cornea. Before applying the cut wound, the animals  were  injected  into  anesthesia  with the  drug  "Sevoflurane".  The  depth  of  the wound was monitored visually using a microscope  at  a  magnification  of  4-6  times. Next,  the  corneal  cut  wound  was  stained with various dyes: animals of group 1 – fluorescein, group 2 – riboflavin, group 3 – bengal  pink,  group  4 –  lissamine  green.  The exposure of all dyes, before eliminating the excess, was 1 minute.

The degree of corneal staining was evaluated and photodocumented immediately after the  elimination  of  excess  dyes  and  further after 10 min., 20 min., 30 min., 60 min., 90 min., and 120 min. The cornea was visualized  and  photodocumented  using  a  microscope "jingleszcn 315W" at magnification x 6.0.

For long-term studies, it is advisable to use bengal pink, which visualizes a wound defect within 60 minutes after staining. Lissamine green should be used in cases where a contrast is needed between the dye and the cornea,  and/or  the  underlying  structures  of the  eye.  Fluorescein  and  riboflavin  diffuse rapidly enough into the surrounding tissues, and also stain the tear film, which can give a false  positive  result  when  diagnosing  a wound defect of the cornea.

Cesarean section, being one of the most common  operations  in  veterinary  surgery, requires  a  special  anesthetic  protocol  that provides adequate anesthesia for the mother and has minimal effect on puppies. The aim of  the  study  was  to  evaluate  the  effect  of various non-inhalation and inhaled anesthetics on newborn puppies during cesarean section,  based  on  the  analysis  of  cord  blood gases.  3  groups  of  experimental  animals were formed, which used one of the studied anesthetic protocols. In the first experimental group, propofol at a dose of 4-6 mg/kg was used to maintain general anesthesia. Inhaled halogen-containing anesthetics were used in the  second  and  third  experimental  groups. Isoflurane 0.5 – 2.0 vol% was  used  in  the second  group,  and  sevoflurane  1.0  –  2.0 vol%  was  used  in  the  third  group.  When using  all  the  studied  anesthetics,  an  acidbase imbalance in the form of moderate acidosis was detected in the puppies after delivery, however, acidosis was less pronounced in the groups where halogen-containing anesthetics were used. The use of inhaled halogen-containing anesthetics had a lesser effect on puppies compared to non-inhalation ones. There were no significant differences in the effect  of  isoflurane  and  sevoflurane  from inhaled anesthetics.

Systemic arterial hypertension can occur in  cats  for  a number of  reasons.  The  most common causes of hypertension in cats include  kidney  disease  (chronic  kidney  disease, chronic interstitial nephritis, amyloidosis, glomerulonephritis, pyelonephritis, polycystic  kidney  disease,  renal  dysplasia,  as well  as  acute  renal  failure),  chronic  heart failure,  endocrinopathy  (diabetes  mellitus, hyperthyroidism,  etc.),  obesity (hyperlipidemia), chronic anemia, polycythemia, fever, arteriovenous fistula, the use of food with a high salt content, idiopathic factors. Taking into account the above, we set a goal –  to  introduce  into  veterinary  clinical practice  an  effective  fibrinolytic  "Actilize"; to establish its effectiveness in lysis of small hemorrhages in the anterior chamber of the eye with arterial hypertension of cats, as well as prevention and treatment of synechiae; to work  out  a  subconjunctival  method  of  administration of "Actilize" at the entrance of long  ciliary  arteries.  The  basis  of  the  research  methodology  was  a  scientifically based formulation of the problem, methods and means of lysis of small blood clots in the anterior chamber of the eye, prevention and treatment  of  synechiae  in  cats  with  arterial hypertension,  ensuring  maximum  effectiveness by improving existing treatment protocols,  as  well  as  testing  "Actilize"  and  the subconjunctival method of its introduction in the area of the entrance of long ciliary arteries  for  treatment  small  hemorrhages  in  the anterior  chamber  of  the  eye  with  arterial hypertension  of  cats  in  veterinary  ophthalmology. Thanks to the experiments, we were able  to  introduce  into  veterinary  clinical practice an  effective fibrinolytic "Actilize"; to establish its effectiveness in lysis of small blood  clots  in  the  anterior  chamber  of  the eye  with  arterial  hypertension  of  cats,  prevention and treatment of synechiae; to work out  a  minimally  invasive  subconjunctival method of administration of "Actilize" at the entrance of long ciliary arteries. In the case of extensive hyphema with arterial hypertension  of  cats,  followed  by  the  formation  of large blood clots, we recommended an intracameral  method  of  introducing  "Actilize" into the anterior chamber of the eye.

Feed injuries and the presence of foreign bodies in the digestive system of cows can be one of the reasons for a decrease in milk yields  and  premature  culling  of  animals. Blood tests in most cases can help determine the degree of exposure of foreign bodies to the  animal's  body.  Morphological  and  biochemical blood analysis can show the presence of inflammation, infection or other diseases associated with the persistence of foreign bodies in the digestive system of cows. Also,  a  blood  test  can  help  determine  the effectiveness of various methods of treating feed  injuries  in  animals.  The  present  study was conducted to study the effect of foreign bodies in the mesh on the morphological and biochemical  profile  of  blood  and  serum  of cattle. The object of the study were Ayrshire cows with a diagnosis of traumatic reticulitis and healthy animals. As a result of the study, we obtained reliable values of deviations in the  morphological  and  biochemical  profile for such indicators as hemoglobin and alkaline  phosphatase.  Taking  into  account  the analysis of the literature and the results obtained  by  us,  traumatic  reticulitis  in  cattle cannot be diagnosed on the basis of individual  laboratory  blood  tests,  since  even  the most  common  deviations  can  not  be  observed in all diseased cows. Many of these indicators are not specific to traumatic reticulitis and may occur in other diseases of the abdominal  cavity  and  chest.  A  preliminary diagnosis can be made only on the basis of all clinical and laboratory data.

The article is devoted to the assessment of changes in the clinical condition, hematological parameters, some biochemical blood parameters  reflecting  the  state  of  protein-carbohydrate metabolism in cows during the milking period, as well as the results of correction of this condition with a feed additive based  on humic acids "Fulvat".  The  article examines the physiological processes occurring  in  the  metabolism  of  cows  during  the newbody period  and  the period  of  separation, reflects the results of the studies conducted in assessing the dynamics and correction of the main critical indicators in hematological, biochemical blood parameters, as well  as  in  vital  changes  in  cows.  The  research  was  carried  out  using  modern  techniques, instruments and equipment. The object of the study was cows, 2-3 lactation of a black-and-white breed. All the animals were on tethered maintenance and a balanced diet. 2 groups were formed for research: experimental and control. The animals of the experimental  group  received  the  main  ration (OR)  +  the  feed  additive  "Fulvat"  for  60 days from the moment of calving; the cows of the control group were kept only on the main ration, without the use of additives in feeding. The feed additive was administered orally with the main diet, mixed with concentrated feed. The total time of observation of the indicators of homeostasis in animals was  60  days.  Studies  have  shown  that  the feed additive has a beneficial effect on erythropoiesis due to the presence of iron, cobalt, copper and other micro- and macroelements in the chemical composition, increasing the level  of  hemoglobin  in  the  experimental group on the 60th day of lactation by 19,7 %, reducing the  risk of developing  a ketogenic situation, increases the level of ionized calcium in the blood of animals, which in 2 times higher, compared with animals in the control group; normalizes the acidity of the scar  content  in  cows  of  the  experimental group and the preservation of the number of infusoria at the physiological level.

Chronic kidney disease in cats is one of the most common diseases. The main direction of palliative therapy for chronic kidney disease  and  extending  the  survival  time  of cats  is  to  limit  phosphates  in  the  diet  and normalize the phosphorus content in the animal’s body. In order to reduce phosphates, phosphate  binders  are  used  -  substances whose mechanism of action is to bind excess phosphate  ions  in  the  gastrointestinal  tract, which  prevents  their  entry  into  the  blood-stream. The purpose of the study is to analyze  the  effectiveness  of  feed  additives “Urdetox” and “Ipakitine” in a comparative aspect in the palliative treatment of chronic kidney disease in cats. Determination of the biological activity of the proposed feed additive for cats with CKD in the form of tablets was  carried  out  on  the  basis  of  veterinary clinics in the city. Volgograd, St. Petersburg, Moscow, in the period 2021-2022. The objects  of  the  study  were  cats  whose  owners complained of loss of animal body weight, often  a  general  depressed  state,  decreased appetite,  periodic  vomiting,  frequent  urination, dull hair. The diagnosis and experiment were  carried  out  by  collecting  anamnestic data, determining clinical signs and laboratory data - a general urine test and a biochemical  analysis  of  blood  serum.  Studies  have shown that feed additives containing a phosphate binder and a detoxicant help eliminate the  main  clinical  manifestations  of  chronic renal failure. The introduction of the essential amino acid -taurine into the feed additive in the form of Urdetox tablets, as well as the accuracy of dosing and ease of use increase the effectiveness of its biological action.

Urolithiasis  is  a  chronic  disease  of  the urinary  tract  of  a  polyethological  nature, accompanied  by  the  formation  of  uroliths and sand in the kidneys and urinary tract, as well as signs of dysuria, pollakiuria, ischuria,  urinary  colic,  periodic  hematuria  and crystalluria. The purpose of our research was to study the metabolism and functioning of the  antioxidant  system  in  cats  with  tripelphosphate  urolithiasis.  The  results  of  our study of the metabolism and antioxidant system  of  sick  animals  indicated  the  development of disorders of redox regulation of cells in tripelphosphate erythrolithiasis in cats. A disorder of liver functional activity was detected  (AST  -  41.74±5.35  Units/l  and 49.30±6.74  Units/L;  ALT  - Units/l  and  Units/L;  ALKP - Units/L and  Units/L; BILT -  mmol/l  and mmol/l; BILD -  mmol/l and 1.62mmol/L;  AAR  –  0.49±0.03  and 0.54±0.02) and violation of cell redox regulation  (MDA  -  1.29±0.08  nmol/ml  and 1.40±0.10  nmol/ml;  SOD -  265.90±12.08 Units/ml and 280.05±10.43 Units/ml; coenzyme  Q10  -  579.03±19.06  ng/ml  and 505.42±23.10  ng/ml;8-OHdG -  0.15±0.01 ng/ml  and  0.13±0.02ng/ml;  ascorbic  acid - 5.03±0.91  mcg/ml  and  4.70±1.03  micrograms/ml; TAS - 1.25±0.07 mmol/l and 1.23±0.05  mmol/L;  GTP -  6234.00±24.82 Units/g Hb and 6015.12±27.56units/g Hb) in cats with tripelphosphate urolithiasis. It was found that there is a direct close correlation between the level of liver transaminases and the activity of antioxidant enzymes, as well as  between  the  level  of  circulating  kidney biomarkers and the level of the main markers of oxidative stress in urolithiasis struvite type in cats, which allows us to expand the understanding of this disease and use these data  in  the  implementation  of  therapeutic measures.