For reliable interpretation of PCR results, it is necessary to use a series of control reactions, namely: a positive, negative and an internal control. Internal control can be of two types: exogenous, which involves adding nucleic acids to the sample being analyzed (during DNA or RNA extraction) for hybridization of primers for internal amplification control, and endogenous, where the nucleic acids for control are already present in the sample itself. This study focuses on analyzing non-species-specific genes from cattle, sheep, and goats and identifying conserved loci that can be used for internal amplification control in the detection of nucleic acids from infectious agents in cattle and small ruminants. A number of genes from cattle and small ruminants were selected for oligonucleotide design, namely: beta-galactosidase, hyaluronidase, diacylglycerol O-acyltransferase, kappa-casein, lactoferrin, neuraminidase, oxytocin, and phosphorylase kinase. Taking into account the nucleotide polymorphism of non-species-specific genes in cattle, sheep, and goats, it was possible to identify the most conserved loci of the analyzed genes for the target animals, suitable for the design of corresponding primers and probes. By comparing the nucleotide sequence differences of the entire gene and its exons for each gene, it was possible to identify the most conserved loci of the exons of two of the analyzed genes, suitable for the design of corresponding primers and probes. Aligning the nucleotide sequences for each gene revealed excessive nucleotide polymorphism across different animals when aligning the nucleotide sequence of the entire gene and its exons. However, when aligning only the exons of the analyzed genes, numerous conserved loci were observed, suitable for designing of corresponding oligonucleotides. Oligonucleotides complementary to the exons (two exons separated by an intron) of the beta-galactosidase and neuraminidase genes were proposed as internal controls for RT-PCR.

Freshwater aquaculture in northwestern Russia, including the Republic of Karelia and the Leningrad, Vologda, and Murmansk regions, primarily specializes in the farming of salmonids (Salmo, Oncorhynchus, Salvelinus) and whitefish (Coregonus). With production intensifying, the natural properties of water bodies changing, and the region’s unique hydroclimatic conditions, bacterial infections are becoming the most widespread and economically significant threat to the industry. The aim of this study is to systematically analyze current data from international genetic databases on the etiology and molecular genetic mechanisms of virulence, as well as to analyze scientific publications on the epidemiology and economic significance of leading bacterial pathogens in freshwater aquaculture in northwestern Russia. A systematic analysis of genetic databases (NCBI GenBank, UniProt) on leading bacterial pathogens in freshwater aquaculture under cold-water fish farming conditions was conducted. The most dangerous nosologies are considered, such as salmon furunculosis (Aeromonas salmonicida subsp. salmonicida), cold-water disease (Flavobacterium psychrophilum), red mouth disease (Yersinia ruckeri), bacterial kidney disease (Renibacterium salmoninarum), and columnaris (Flavobacterium columnare). The molecular genetic determinants of virulence for each pathogen are examined, including the type III (T3SS) and type VI (T6SS) secretion systems, the main toxins, and adhesion factors. The increasing role of antibiotic resistance, including horizontal transfer of resistance genes, as a systemic threat in the context of the One Health concept is demonstrated. A conclusion is drawn regarding the need to introduce multiplex molecular diagnostics, regular genomic surveillance of circulating strains, and improved biosecurity on fish farms into domestic practice.

Feline leukemia virus (FLV) is an exogenous pathogen capable of replicating in a wide range of tissues, including bone marrow, salivary glands, and respiratory epithelium. In the absence of an adequate immune response after primary infection, the pathogen migrates to the bone marrow, where it invades hematopoietic progenitor cells. This virus is one of the most aggressive feline retroviruses and causes more clinical manifestations than any other pathogen. It is a leading cause of immunodeficiency, cancer, and death in pets. This viral agent is of significant interest due to its diverse and difficult-to-diagnose forms, the lack of treatments that directly address the underlying cause, and the difficulty of disease management. The objective of this study was to retrospectively analyze the prevalence of FLV and FLV in cats. Data was collected from 2024 and 2025 on blood samples from cats of different ages and breeds. PCR diagnostics were used to detect feline leukemia virus (RNA and DNA) and feline immunodeficiency virus (FIV) DNA. We noted a predominance of cases in animals under one year of age, between one and two years of age, and over seven years of age. Over the two years, the most common cases were feline leukemia virus (FVLV) containing DNA and RNA (93/75), feline immunodeficiency virus (FIV) (49/48), and associated infection (FeLV containing DNA and RNA and FIV) (21/19). No breed predisposition to these infectious diseases was observed. The predominance of British and Scottish cats in the study is explained by owners’ interest in a particular breed and the health status of their animals.

Newcastle Disease (ND) is a highly contagious viral infection of birds that causes significant economic losses in the poultry industry. Traditional whole-virion vaccines often fail to provide crossneutralizing im-munity, emphasizing the need for innovative approaches to the design of new vaccine candidates. Conducting a comprehensive bioinformatics analysis of VBN representatives is necessary to achieve such goals as the creation of new candidate vaccines with a broad spectrum of protection, including DIVA-compatible ones, increasing the specificity and sensitivity of diagnostic tools, as well as overcoming the problem of antigenic drift, which will allow for the rapid adaptation of the composition of vaccines and diagnostics in accordance with the current epizootic situation. In this study, a bioinformatic analysis of the proteomes of the major Newcastle disease virus (NDV) antigens — the F and HN proteins — was carried out to identify potential immunogenic epitopes. Using sequences of var-ious viral strains circulating in Russia and neighboring countries, deposited in the GenBank database, both B-cell and T-cell epitopes were identified. The applied prediction algorithms showed that the regions with the highest epitope density are associated with critical functional domains of the proteins involved in viral membrane fusion and host receptor recognition. The results indicate high potential immunogenicity of several identified sequences. Information on epitope local-ization and antigenicity assessment serves as a foundation for further studies aimed at developing recombinant vaccines and highly specific diagnostic tools, which are key to effective control of ND spread in bird populations. This study highlights the importance of a targeted approach to vaccine design under the condi-tions of continuous antigenic evolution of the virus.

Bird droppings, widely used as organic fertilizer in agriculture, pose a serious threat to human health and the environment due to the presence of antibiotic residues and antibiotic resistance genes. Litter monitoring for the presence of antibiotic-resistant bacteria is an urgent task to minimize the risks of spreading antimicrobial resistance in the environment. The aim of the study was to study the species composition and antibiotic resistance profiles of bacteria isolated from the droppings of healthy poultry at seven enterprises in the Siberian region. A study of 280 litter samples from healthy laying hens and broiler chickens of different ages was conducted. The indication of microorganisms was carried out by methods generally accepted in microbiology using simple and differential diagnostic nutrient media, identification to the species was carried out using the technology of matrix laser desorption ionization time-of-flight mass spectrometry (MALDI-ToF MS). Bacterial resistance was studied by the disco-diffuse method. The sensitivity of 550 isolated isolates to 26 antibacterial drugs of various pharmacological groups was studied. Based on research, it was found that the microbiocenosis of the litter of healthy chickens is dominated by bacteria of the Enterobacteriaceae family — 46,0 % (Escherichia coli, Proteus mirabilis) and Staphylococcaceae — 29,8 %. When studying their antibiotic resistance profiles, representatives of the opportunistic microflora from the Staphylococcaceae family showed the greatest resistance to the studied antibiotics: 95—100 % of the cultures were resistant to penicillins, fluoroquinolones, tetracyclines, macrolides and lincosamides, while in 100 % of cases they were polyresistant. Among the representatives of the Enterobacteriaceae family, over 50 % of Escherichia coli and Proteus mirabilis isolates were resistant to antibiotics from the penicillin and fluoroquinolone group, polyresistance was detected in 16,6 % and 13,3 % of cultures, respectively.

Due to the widespread prevalence of respiratory viral diseases, particularly respiratory syncytial infection (RSI), among young cattle, the development of vaccines for immunizing young calves is extremely important. One of the most promising areas is the development of intranasal vaccines, as they, along with general immunobiological protection, promote the development of local immunity in the mucous membranes. This method, in turn, allows for immunization without the risk of maternal blockade. At the same time, the safety of such vaccines should be given special attention, as the first days of life are the most critical period for any external influences. The aim of this study was to evaluate the safety of a candidate intranasal RSI vaccine, being developed at the Federal Center for Toxicological, Radiation and Biological Safety, using a laboratory animal model (rabbits). Safety testing was conducted in accordance with GOST 31926-2013 on Chinchilla rabbits (three animals per group). The lyophilized monovalent vaccine was presuspended in sterile saline. Intranasal, intraperitoneal, intramuscular, and subcutaneous administration routes were used for safety testing. Animals were observed for 14 days. The volume of vaccine administered was 1,0 cm3 intranasally, 10,0 cm3 intramuscularly, 10,0 cm3 subcutaneously, and 10,0 cm3 intraperitoneally per animal. The vaccine was considered safe if no deterioration in the general condition, visible tissue changes at the injection site, illness, or death of the animals was observed during this period. In addition, after 14 days, a postmortem autopsy of the rabbits was performed to determine the absence of a systemic negative effect of the vaccine on tissues and internal organs. Autopsy was performed using the Virchow method, with measurement of the weight of internal organs and opening of the nasal cavity to examine the labyrinth mucosa. The monovalent vaccine against RSI did not cause clinical signs of the disease or mortality in rabbits. Visual inspection and comparison of organ weights revealed no differences between the experimental and control groups. These results demonstrate the safety of the vaccine being developed.

The development of livestock farming in the Russian Federation, using modern technology and innovation, is an integral part of the state program to improve agricultural efficiency. Increasing the production of milk, meat, and other food products is of strategic importance as a key indicator of the country’s economic growth and the optimization of foreign economic relations. Invasive diseases are one of the constraints on livestock development. They cause significant damage to farms due to the mass mortality of animals during enzootic outbreaks, the stunting of young animals, decreased resistance to infectious and non-infectious diseases, reduced productivity and fertility, deterioration in meat and hide quality, and increased costs for veterinary and sanitary measures. This article presents the results of a study examining the prevalence of parasitic diseases among farm animals and poultry in livestock and poultry farms, as well as enterprises of various types of ownership in the Irkutsk Region. In the period from 2015 to 2023, nematodoses dominated among parasitic diseases of farm animals and birds with an average long-term indicator of extensiveness of invasion: in cattle 12,8±1,11 % (r=0,68; P≤0,001), horses — 22,9±4,05 % (r=—0,18; P≤0,001), small cattle — 17,4±2,86 % (r=0,14; P≤0,05), pigs — 13,5±1,82 % (r=—0,40; P≤0,01) and poultry — 4,3±2,46 % (r=0,34).

The etiology of mastitis is associated with a high percentage (90 %) of isolation of bacteria of the genus Staphylococcus. According to statistics, the problem of mastitis in lactating cows is relevant, since it is associated with the economic costs of treatment and diagnosis. Modern diagnosis of infectious mastitis, based on biomarkers (interleukins) of the inflammatory process, will allow assessing the course and form of mastitis, and significantly reduce the economic costs of diagnosis. The purpose of the study was to determine the concentration of pro-inflammatory (IL-1 β, IL-2, IL-6, IL-8) and anti-inflammatory (IL-4, IL-10) interleukins, in milk and blood serum, in different groups of dairy cows, so that the obtained concentration values could be used as predictive biomarkers of the course of infectious mastitis of staphylococcal etiology. To conduct the study, 3 groups of 10 heads of lactating red-and-white Holstein dairy cows were formed. 10 milk samples and 10 blood samples were taken from each group of dairy cows: clinically healthy, with subclinical and clinical mastitis. The basis for the division into groups was the rapid test for mastitis. To determine the concentration of pro-inflammatory and anti-inflammatory interleukins in serum and milk, the enzyme-linked immunosorbent assay method and the corresponding set for determining the concentration of a particular interleukin were used. The obtained values of concentrations in milk were promising, in particular, IL-2 was increased by 9,9 times in the group of clinically ill mastitis compared to the group of clinically healthy and IL-6 in the group of clinically ill mastitis by 9,5 times compared to the group of clinically healthy cows. Serum interleukin concentrations were increased: for IL-2, 4.2 times between the group of clinically ill mastitis and the group of clinically healthy cows, and IL-6 concentration in the group of clinically ill mastitis was 9,5 times higher compared to the group of clinically healthy cows.

Salmon farming and fish farming in the Northwestern Federal District (NWFD) account for over 70 % of Russia’s commercial trout production and a significant share of whitefish and sturgeon products. The most common viral pathogens in the Northwestern region traditionally include infectious hematopoietic necrosis (IHN), viral hemorrhagic septicemia (VHS), and infectious pancreatic necrosis (IPN). The survey covered fish farms in the Leningrad Region (cage and tank farms), the Republic of Karelia (cage farms on lakes and rivers), and the Novgorod Region (flow-through farms). The study was conducted from 2021 to 2025; sample collection was timed to coincide with periods of recorded fish mortality with at least a 10% loss in 7 days. Rainbow trout (Oncorhynchus mykiss), Atlantic salmon (Salmo salar), whitefish (Coregonus lavaretus), and other species were studied. Samples included groups of various ages, from juveniles weighing 1–5 g to commercial fish. Renibacterium salmoninarum, motile aeromonads of the Aeromonas hydrophila complex, as well as viral agents IHN, VHS, and IPN, were not associated with the epizootic situation we recorded during our survey of fish farms in the Leningrad Region, the Republic of Karelia, and the Novgorod Region in 2021—2025. The main etiologically significant agents of mass fish mortality in the surveyed farms were: Lactococcus garvieae, Aeromonas salmonicida subsp. salmonicida, Yersinia ruckeri, Flavobacterium psychrophilum, and Pseudomonas spp. Collectively, these pathogens accounted for at least 80 % of the recorded livestock mortality. This paper describes the clinical presentation for each disease entity, as well as strategies for using PCR protocols and molecular targets for molecular genetic verification of the pathogen.

Equine piroplasmosis remains relevant in veterinary practice owing to the possibility of acute disease and latent carrier status, in which laboratory detection of the pathogen is difficult. The aim of the study was a pilot assessment of agreement between blood smear microscopy, local screening PCR and laboratory real-time PCR for the detection of Babesia spp. in horses of different clinical status. Fourteen animals were examined. All underwent clinical examination, microscopy of thin peripheral blood smears, screening PCR using a commercial kit for the detection of Babesia spp. DNA, and testing in an accredited veterinary laboratory, the results of which were used as the comparator method. The full protocol of the laboratory method was not disclosed, therefore it was used as a comparator rather than an absolute reference method. Clinical signs compatible with acute infestation were recorded in 3 of 14 animals, in which the pathogen was detected by microscopy and screening PCR. Laboratory PCR was positive in 10 of 14 horses, including clinically healthy animals negative by the routine methods. Positive percent agreement of microscopy and local screening PCR with the comparator was 30,0 % each, negative percent agreement was 100,0 and 75,0 %, respectively. Cohen kappa was 0,196 and 0,034, indicating slight agreement. Values are reported with 95 % confidence intervals calculated by the Wilson method. A negative result of the routine methods does not exclude Babesia spp. infestation in clinically healthy horses. The findings are preliminary and require verification in an expanded sample using a validated reference method.

The article presents an assessment of the effect of complex therapy of respiratory pathology on the expression of IFNAR1, IKBKB genes and indicators of cellular immunity in 3-month-old calves. Three
groups were formed for the experiment: healthy animals (n=10) – group I; sick calves treated with «Azitronit» and «Butophan» (n=10) — group II; sick calves treated with «Azitronit» and «Proautovac» (n=10) — group III. It was found that after 5 days, IFNAR1 expression in all the studied groups approached the values of healthy animals, and after 7 days it was completely suppressed. The expression of the IKBKB gene in group II calves 7 days after the start of treatment corresponded to the indicators of group I animals, and in group III calves it was 2 times lower. 5 and 7 days after the start of treatment with «Proautovac», a significant increase in the PhAL was recorded by 3,4 % and 4,3 % in calves compared with group II. The PhI and PhN in group III animals were higher than in group II by 11,3 % and 10,0 % 60 hours after the start of treatment, by 21,3 % and 28,2 % after 5 days, and by 18,1 % and 14,2 % after 7 days. 7 days after the start of treatment, the blood levels of B- and T lymphocytes in group III calves were 21,0 % and 29,2 % higher than when using «Butophan». At the end of the experiment, the indicators of cellular immunity when using «Proautovac» did not differ statistically significantly from healthy animals. Thus, the use of «Proautovac» provided faster normalization and restoration of signaling pathways and cellular mechanisms of immunity, which justifies the use of cytokine-based drugs (type I/II interferons, GM-CSF and vitamins A, E, and C) in the complex treatment of bronchopneumonia in calves.

For the northwestern regions of Russia, where industrial fish farming is focused on cold-water salmon, whitefish (Coregonus spp.), and char (Salvelinus spp.) species, four viral nosologies form a stable pool of constant epizootic pressure: viral hemorrhagic septicemia (VHSV genotype II, dominant in the Baltic basin), infectious hematopoietic necrosis (IHN), infectious pancreatic necrosis (IPN), and salmon pancreatic disease caused by alphavirus (SAV). The aim of this study was to analyze the degree of virological threat to fish farms in a specific region and such key aspects as the molecular mechanisms by which viruses evade the antiviral immunity of fish, epidemiological routes of pathogen introduction into farms through the international circulation of seed and caviar, data on the susceptibility of whitefish and char species to viruses, which in some cases exceed the susceptibility of the main model species, rainbow trout (Oncorhynchus mykiss). An analysis of the whole genome sequences of VHSV (NC_000855.1), IHNV (GQ413939.1), IPNV (AJ622822.1), and SAV (AY604235.1) from the NCBI GenBank and RefSeq databases was conducted. Urgent needs for virological monitoring of fish farms in the Northwest, based on molecular genetic detection methods, were formulated. We concluded that the key practical measures capable of significantly reducing the virological risk to the industry include: the introduction of multiplex RT-PCR screening of imported material for VHSV, IHNV, IPNV, and SAV; the organization of regular monitoring of fish on farms based on these methods; the creation of a Russian database of reference sequences and circulating isolates; and the development of specialized protocols for whitefish and char as separate monitoring targets.

One of the directions of the implementation of the country’s food security program is the development of animal husbandry, as one of the sources of providing the population with high-quality food. Achieving this goal is closely linked to reducing the incidence of animal diseases and the cost of their veterinary care, which ensures a reduction in the cost of final products. A significant obstacle on this path is a group of diseases characterized by nonspecific symptoms and long-term latent course, which include genital mycoplasmosis of cattle. The treatment of animals with mycoplasmosis is based on the use of antibiotics. The aim of the work was a retrospective analysis of changes in the sensitivity of mycoplasmas to the main groups of antibacterial drugs used for the treatment of animals, to identify the causes of the pathogen’s resistance to them, and to identify the most promising antibiotics for the treatment of animals with mycoplasmosis. In the course of studying foreign and russian literature sources, it was found that there was a significant decrease in the sensitivity of mycoplasmas to drugs that demonstrated high therapeutic efficacy 30—40 years ago, to a lesser extent there was a decrease in sensitivity to effective antibiotics 15—20 years ago. It has been established that a similar trend is observed in mycoplasma strains isolated in different countries and on different continents. The main reason for the increased resistance of mycoplasmas to antibiotics are point mutations. To date, the greatest resistance in most mycoplasma strains is observed to the following drugs: tetracycline, doxycycline, erythromycin, tylosin, tilmicosin, marbofloxacin, high sensitivity to chlortetracycline, azithromycin, tulatromycin, spiramycin, enrofloxacin, danofloxacin remains.

Mastitis remains one of the main causes of economic losses in dairy farming due to reduced productivity, deterioration of milk quality and premature culling of cows. The analysis of the prevalence of mastitis in Holstein cows in a high-tech complex was carried out and the effectiveness of the stepwise treatment regimen used was assessed. The study was conducted in 2025 on a population (n=2743) of cows of 1—9 lactation with an average productivity of 30—40 liters/day. Data on morbidity and culling are obtained from the DairyComp program, depending on the month and number of lactation. The overall incidence of mastitis was 7,73 %. The peak incidence occurred in the 2—3 months of lactation, reaching 1,46 % of the total number of lactating cows. A direct correlation was found between age, the incidence of mastitis and the proportion of recovered animals. In the first heifers, the incidence was 3,81 %, and recovery was 84,21 %. By the 6^th lactation, the incidence rate increased to 23,53 %, and the proportion of those who recovered decreased to 25.0 %. In cows of 7-8 lactation, the incidence reached 60 %, with the effectiveness of treatment – up to 33%. The initial treatment regimen was used in 100v% of sick cows, and its effectiveness was 45,75 %. The transfer to subsequent schemes was accompanied by a decrease in the proportion of those who recovered to 22,2 % and an increase in culling to 74,1 %. Chemical involution of a quarter, as a last resort, was effective in 100% of cases, but was applied only in 1,42 % of diseased animals. The prevalence of mastitis in the herd is agerelated, with a critical increase in risk after 3—4 lactation, due to the accumulation of fibrous changes in breast tissue and decreased immunity. The existing step-by-step treatment system allows the livestock to be stratified by therapeutic potential, however, the effectiveness of initial therapy requires optimization to reduce the proportion of forced culling, which amounted to 32,08 % of the number of sick cows.

The aim of this study was to determine the seasonal prevalence of strongyloidiasis in cattle on livestock farms in the Amur Region. Cattle were tested for strongyloidiasis at several livestock farms in the Amur Region. A total of 1,280 fecal samples were collected monthly from the same groups of animals throughout the calendar year. Coprological examination of the samples was performed for the presence of nematode eggs and larvae using the sedimentation method (acetic acid-ether). The samples were cultured for 8—10 days, and then the presence of nematode larvae was determined using the Berman method. The prevalence of infestation was calculated and the coefficient of variation (seasonal dynamics) of S. papillosus in cattle was determined. The average monthly prevalence of infestation was 17,2 %. Peak values were recorded in the winter-spring and summer periods: January (EI 21,8 %), March (EI 22,6 %), April (EI 19,6 %), June (EI 23,6 %), August (EI 21,8 %), with p<0,001. The summer peak is associated with the accumulation of larvae in pastures. The winterspring peak is associated with the activation of S. papillosus larvae in favorable indoor conditions against the background of decreased resistance of animals. The period of low infestation (decline) was noted in July (EI 5,5 %), October (EI 9,6 %), November (EI 11,0 %) with p<0,05 and February (5,6 %). Strongyloidiasis is recorded in all seasons of the year with varying values: spring (Kc = 25,5 %), summer (Kc = 43,6 %), autumn (Kc = 16,8 %), and winter (Kc = 14,1 %). The most epizootic season for strongyloidiasis in cattle is summer (Kc = 43,6 %). S. papillosus infestation is persistent and has a pronounced seasonality; the coefficient of variation was 41,0 %, which must be taken into account when planning timely diagnostic, treatment, and preventive measures.

The author has experimentally established that the use of virus vaccines for the prevention of viral diseases in gherkin chickens reduces their natural resistance to colibacillosis several times. A challenge infection of vaccinated chickens with E. coli strain № 16-6 at a dose of 0.5•LD50 causes the development of colisepticemia, unlike the controls. The most active depressant of the natural resistance of chickens is the Newcastle disease virus, which reduces resistance to colibacillosis to -7 uer. (conventional units of resistance), that is, 14 times, compared to the control. Gherkin production is generally carried out on small farms free from infectious diseases, adhering to the «Everything is full - everything is occupied» principle, not only for individual poultry houses, but for the entire farm. The overwhelming majority of chickens easily tolerate these conditions for their rearing for 16-18 days. Keeping chickens isolated from the environment and kept indoors prevents the development of infectious processes. Therefore, artificially inducing infections during rearing is undesirable. Therefore, the use of viral vaccines in many cases has significant limitations, as vaccination with viral vaccines provokes the emergence and development of colibacillosis in the flock. The use of sanitary preventive measures is often sufficient for the normal rearing of gherkin chickens. In this article, the author studied the quantitative characteristics of the reduction in chicken resistance to colibacillosis after vaccination with commercial live virus vaccines. It was found that challenge infection of vaccinated chickens with E. coli strain No. 16-6 at a dose of 125,000 CFU/kg body weight (0.5•LD50) caused the development of colibacillosis, unlike the controls.

This article presents the results of long-term (1958–2026) epizootological monitoring of brucellosis in reindeer in the Republic of Sakha (Yakutia). It was established that the region has remained consistently unfavorable for this infection for over 60 years. The first routine diagnostic studies began in 1958 in six uluses, and by 1964, the disease was being recorded in all reindeer herding farms. The main factors maintaining the circulation of the pathogen were identified. The dynamics of the epizootic situation are shown. In 2009, 136,662 animals were tested (73 % coverage), and 547 infected animals (0,4 %) were identified. By 2010, the number of affected areas had decreased to 49. As of February 2026, there were 13 affected areas, 7 of which were for brucellosis in domestic reindeer. Infection rates vary by natural and climatic zone: 0,6—1,3 % in the tundra, 0,1—2,2 % in the mountain-taiga and forest-tundra, and no cases have been recorded in the taiga zone. An occupational risk of infection has been established. Among reindeer herders on some farms, seropositive individuals accounted for up to 4,8 %. Successful rehabilitation of affected areas in the Bulunsky, Tomponsky, and Olenyoksky uluses was achieved through a comprehensive approach, including the participation of local governments, farm managers, and reindeer herders. Despite the reduction in the number of affected areas, reindeer brucellosis in Yakutia remains an epizootic concern due to the presence of natural foci among wild reindeer, infrastructure limitations, and insufficient diagnostic testing. Achieving sustainable disease control requires further improvement of the system of measures, including modernization of corrals, optimization of drug delivery logistics, and scaling up of effective diagnostic procedures.

The article discusses the current problem of parasite resistance to anthelmintics and proposes measures to prevent it. An analysis of the literature data showed that parasite resistance is formed due to excessive and incorrect use of drugs, as well as under the influence of their genetic characteristics. The current veterinary regulations do not provide sufficient systematization in the fight against helminthiasis, which necessitates a scientific assessment of the applied strategies. The results of the 2023—2025 study indicate a high prevalence of helminths in horses in the North-Western Economic Region, where macrocyclic lactones are the preferred drugs for deworming. The widespread use of the same groups of anthelmintics and a subjective approach to determining animal weight significantly increase the risk of resistance development. In this regard, it is proposed to switch to a more rational approach — selective deworming, based on diagnostics and regular monitoring of the extensiveness and intensity of the invasion by conducting FECRT (Faecal Egg Count Reduction Test) when the ineffectiveness of treatments is suspected. This approach will reduce the selective pressure on the parasite populations and slow down the process of the formation of resistance. The basis of the strategy to prevent resistance to anthelmintics is a diagnostic-oriented approach. It is necessary to identify «super-producers», as about 20 % of horse’s produce 80 % of the eggs, to deworm these animals, and to regularly monitor the intensity of the infestation using the FEC test to identify horses that produce more than the threshold value of eggs (200 eggs/g for parascarids and 500 eggs/g for strongylides). Fecal analysis should be carried out 4—6 times a year. Selective deworming may be risky for foals, as parascarids can cause obstructive ileus in young animals with high infection rates. In farms with a high prevalence of parascaridiasis, deworming should be performed even at low egg counts in feces to prevent acute cases and animal deaths. When rotating drugs, it is important to consider their mechanism of action and pharmacological group.

Glyphosate is the most widely used broad-spectrum herbicide. The aim of this study was to investigate the effects of various antioxidants on the intestinal microbiota and histostructure of white rats exposed to glyphosate. The efficacy of potential candidate components (calcium succinate at 25 mg/kg body weight, ammonium fumarate at 25 mg/kg, and curcumin at 0,04 % of the diet) with antitoxic effects against glyphosate pesticide poisoning was assessed using 30 white rats divided into 5 groups. Exposure to the glyphosate-based preparation resulted in a 34,4 % (p<0,001) and 36,7 % (p<0,001) decrease in lacto- and bifidobacteria, and a 30,0 % (p<0,001) increase in Escherichia coli counts, compared to the biological control. Yeast fungi, salmonella, and hemolytic Escherichia coli were detected in the feces of animals in the toxic control group. Curcumin demonstrated the highest response to glyphosate. The effect of ammonium fumarate was insignificant, and calcium succinate demonstrated the least ability to restore the normal microbiome composition of white rats poisoned with glyphosate. The histological picture of the small intestine of biological control rats was normal. Histological sections of rats given only glyphosate showed edema of the mucosal and submucosal layers, as well as focal epithelial necrosis. Mucosal edema with individual cell necrosis was observed in the intestines of rats given glyphosate and calcium succinate. Rats given glyphosate and ammonium fumarate showed signs of mucosal edema in the intestines. In histological preparations of rats treated with glyphosate and curcumin, the intestinal structure did not differ from the control.

The widespread use of antimicrobial drugs in poultry farming necessitates assessing their impact not only on bacterial pathogens, but also on the immune status of poultry. The aim of this study was to investigate the effect of various groups of antimicrobial agents on the phagocytic activity of blood cells in chickens. The experiment was conducted on six groups of egg-laying chickens. The control group received clean water, and the five experimental groups were given sulfaguanidine, furazidine, nifurantel, sulfasalazine, and amoxiclav at a dosage of 200 mg/L for 10 days. Blood samples were collected on the first, third, fifth, seventh, and ninth days after the drugs were discontinued. The phagocytic activity, phagocytic number, and phagocytic index of pseudo-eosinophils were studied after 30 and 120 minutes of coincubation with Saccharomyces cerevisiae. The studied drugs were found to have different effects. Furazidin showed the most pronounced immunostimulating properties: on the fifth day after discontinuation, there was a significant increase in phagocytic activity by 12,8 % and the phagocytic index by 25,2 % compared to the control, indicating a comprehensive activation of phagocytosis. Sulfanilamides showed an immunosuppressive trend. In the sulfaguanidine group, a 27,6 % decrease in the phagocytic number was observed on the third day, while sulfasalazine caused a 20,1 % decrease in phagocytic activity by the ninth day. Amoxiclav had the most pronounced inhibitory effect in the early period, with a 42 % decrease in the phagocytic index and a 45,7 % decrease in the phagocytic number on the first day, but these values returned to normal by the fifth day. Nifurantel demonstrated complex modulatory dynamics: on the seventh day, an increase in late phagocytosis was observed against a decrease in early phagocytosis. The antimicrobial drugs studied have a significant immunomodulatory potential, which varies from delayed stimulation to prolonged suppression and reversible early immunosuppression.

The development of high-performance probiotic strains capable of synthesizing therapeutic proteins requires an integrated approach combining genetic engineering with optimization of fermentation conditions. In this study, an improved three-stage cultivation protocol for a recombinant Lactobacillus spp. strain co-expressing interleukins IL-10 and IL-22 was developed and validated in a bioreactor with automatic control of critical parameters, including pH, temperature, and dissolved oxygen. Recombinant strains transformed with the pLacDualIL10/IL22 plasmid were used. Cultivation was performed in a glass bioreactor (working volume 600 mL) equipped with automated monitoring and regulation of pH, temperature, and dissolved oxygen. A three-stage режим was implemented, consisting of a growth phase (37°C, pH 6.8), an induction phase (1 mM IPTG, 30°C), and a production phase. Protein purification was carried out by tangential flow ultrafiltration followed by affinity chromatography on Ni-NTA agarose. Quantitative determination of IL-10 and IL-22 was performed using ELISA; purity was assessed by SDS-PAGE, and biological activity was evaluated using a PBMC lymphocyte proliferation assay. Application of the three-stage strategy resulted in a significant increase in target protein yield, reaching 120±15 mg/L for IL-10 and 95±10 mg/L for IL-22, which is 2—3 times higher than that achieved in flask cultivation. Subsequent purification provided high-purity proteins (>95 % and >93 %, respectively) with preserved biological activity of 1,2×106 U/mg for IL-10 and 8,5 × 105 U/mg for IL-22. The proposed methodology demonstrates high reproducibility and efficiency, confirming its potential for scalable production of functional recombinant cytokines using a probiotic platform.

Fusarium fungi are ubiquitous in various ecological niches and are important pathogens for plants, animals, and humans. Fusarium fungi, which produce various types of mycotoxins, are the most common among the many genera that produce mycotoxins. The purpose of these studies was to evaluate the effectiveness of the use of antitoxic serum when exposed to Fusarium toxins (T-2 toxin, deoxynivalenol, zearalenone and fumonisin B1). The experiment was performed on 24 white rats, divided into 4 groups according to the principle of analogues (n=6). The animals of the first (biological control) and fourth groups (control of the harmlessness of the studied agent) received food that did not contain mycotoxins. The second group received a feed containing a mixture of fusariotoxins at the level of twice the maximum permissible concentration (MPC): T-2 toxin — 0,2 mg/kg, deoxynivalenol — 2 mg/kg, zearalenone — 2 mg/kg, fumonisin B1 — 10 mg/kg. On days 1, 7, and 14, white rats of the third group were intramuscularly injected with antitoxic serum at a dose of 0,3 cm3 per 1 kg of body weight against the background of Fusarium mycotoxins. The fourth group of animals was injected with antitoxic serum according to a similar scheme. Studies have shown that combined exposure to Fusarium toxins at concentrations corresponding to 2 MPC in laboratory animals results in toxic effects. These include hematological changes (decreased blood counts and hemoglobin levels) and biochemical changes (decreased total protein and glucose levels, increased bilirubin concentrations, and increased aminotransferase activity). Furthermore, increased lipid peroxidation (LPO) and a corresponding increase in malondialdehyde (MDA) levels by 15,3 % (p<0,01) were observed compared to the control group. This led to the accumulation of T-2 toxin in the liver of the experimental animals, reaching 15,00±3,55 mg/kg. Intramuscular administration of therapeutic serum during mycotoxin administration reduced the toxic effects of fusariotoxins. Thus, in animals receiving a fusariotoxin mixture and therapeutic serum, T-2 toxin levels were reduced by 2,7 times compared to the control group.

Aluminum hydroxide [Al(OH3] is widely used in medicine as a component of antacids and as an adjuvant in vaccines. However, its safety during chronic alimentary exposure remains a subject of debate, particularly in the context of potential accumulation in the central nervous system and neurotoxic effects. Aluminum is a common metal, the effects of which on the central nervous system raise serious scientific concerns. The aim of this study was to comprehensively evaluate the effects of chronic aluminum hydroxide administration on neurobehavioral characteristics, histomorphological structure, and essential element metabolism in the rat brain. A chronic alimentary exposure model using varying doses of aluminum was used. The results showed dosedependent accumulation of aluminum in the brain and a statistically significant increase in magnesium levels at high doses. Changes in iron levels were inconsistent, while calcium levels remained stable. Behavioral tests revealed no significant cognitive impairment, indicating that the animals retained cognitive resilience during chronic exposure to the selected doses of aluminum. The histological analysis revealed no signs of significant neurodegeneration or gross structural pathologies in the brain tissue samples. A significant limitation of this phase of the study is the lack of standardized sampling of identical cortical areas for all animals, which precludes quantitative comparative conclusions regarding neurodegenerative changes. Thus, the data obtained expand our understanding of the multifaceted neurotoxic effects of aluminum during chronic exposure and highlight the need for further research into the mechanisms of its action on brain function and structure.

The study evaluated the effectiveness of testicular hyaluronidase in the treatment of mastitis in cows. The research was conducted on Holstein animals with recurrent catarrhal inflammation of one udder quarter (more than twice per lactation). All animals (n=20) underwent therapy, which included a supramammary novocaine block and an injection of an anti-inflammatory agent on the first day of treatment, as well as intracisternal administration of the drug «Mastiet Forte» until clinical recovery. The experimental group (n=10) additionally received an intracisternal injection of 1280 units of hyaluronidase diluted in 5 ml of saline solution. The results showed that in the experimental group, compared to the control, the somatic cell count was lower by 115.2 thousand/ml, and the number of animals with an inflammatory reaction cell concentration in the secretion exceeding 500 thousand/ml was lower by 20 %. The electrical conductivity of milk in the cows of the control group decreased by 28,6 %, while in those receiving the enzyme it decreased by 34,5 %, which is 22,1 % less compared to the animals receiving standard treatment (P≤0,01). The course of intracisternal administrations when using hyaluronidase was shortened by 0,9 days. During the one-month observation period, a relapse of the pathology was noted in one cow from the experimental group compared to three in the control group. Hematological analysis revealed that therapy with the enzyme promoted active resolution of persistent inflammation: a decrease in the number of monocytes and eosinophils, and a shift in the leukogram towards neutrophilic leukocytes, whereas in the control group these changes were less pronounced. Thus, the use of testicular hyaluronidase in the complex treatment of recurrent mastitis in cows increases the clinical effectiveness of the therapy.

The aim of this study was to investigate the correlation between serum CYPOR levels and the pharmacokinetic parameters of caffeine and sorbitol in laboratory animals with induced hepatobiliary pathologies. Testing this hypothesis will substantiate the possibility of using CYPOR as a surrogate biomarker for predicting individual variability in xenobiotic metabolism in animals with liver disease. The study was conducted on 120 laboratory rats of both sexes weighing 180—220 g. Modeling of hepatobiliary pathologies was carried out in accordance with the «Guidelines for the Experimental (Preclinical) Study of New Pharmacological Substances» edited by R.U. Khabriev (2005). Acute toxic hepatitis was induced by administering methyl trichloride using a patented method (patent RU2821264C1). Fatty liver was modeled using strontium sulfate and a high-fat diet according to patent No. 2766772C1. Ulcerative gastrointestinal lesions were induced by administering indomethacin. Animals were divided into experimental groups based on gender: control (intact), toxic hepatitis, fatty liver, gastrointestinal ulceration, and groups receiving exogenous cytochrome C against the background of the indicated pathologies. CYPOR concentrations in serum were determined by enzyme-linked immunosorbent assay using commercial kits (Cloud-Clone Corp., USA). CYPOR levels were shown to exhibit a strong inverse correlation with caffeine half-life (r=–0,85, p<0,01) and a direct correlation with its clearance (r=0,88, p<0,01), confirming the key role of CYPOR as an obligate electron donor for CYP1A2-mediated metabolism. For sorbitol, correlations with CYPOR were moderate (r=0,55—0,60), indicating the limited applicability of CYPOR as a predictor of the pharmacokinetics of substrates with a predominantly extracytochrome elimination pathway.

Ensuring a consistent volume and quality of output is one of the key challenges in modern livestock farming. To achieve this, various methods are used to optimize and increase production, particularly by increasing the working herd. Enhancing production efficiency in modern livestock farming is directly associated with the implementation of precision technologies for monitoring the physiological condition of animals. The relevance of this topic arises from the urgent need to shift from traditional, labor-intensive observation methods toward automated systems that enable continuous monitoring and timely management decisions. The objective of the present study is to conduct a comprehensive comparative analysis of current methods for identifying and monitoring cattle activity using transponder-based systems. The paper provides a detailed evaluation of the technical characteristics, functional capabilities, and practical applicability of various sensor types currently available on the market. The analysis covers widely adopted solutions such as ear tags, collars, and ruminal boluses, as well as less common systems including halters and leg-mounted bands. For each device type, key parameters are examined, including the range of measurable physiological and behavioral indicators, attachment reliability, data accuracy and validity, and adaptability to different livestock housing systems. The results highlight the absence of a universal solution and reveal the specific advantages and limitations of each technology, determining their suitability for particular production objectives. In conclusion, the study emphasizes the importance of selecting monitoring technologies based on a comprehensive consideration of farm-specific priorities — an essential factor for the successful digitalization of herd management processes. Future perspectives are linked to the development of integrated platforms capable of aggregating data obtained from multiple cattle activity monitoring systems.

The health and productivity of poultry are largely determined by their gut microbiota. The ceca are an important part of the intestinal tract of birds and are characterized by a unique microbiome capable of influencing key physiological and biochemical processes. This article examines the taxonomic diversity of microorganisms in the ceca of laying hens and their relationship with gene expression in the bird’s organs. Studying the composition of the microbiota and its relationship with gene expression in laying hens’ tissues provides valuable insights into the mechanisms by which the microbiome regulates biological functions and adaptive responses. The aim of this study was to investigate the correlations between the taxonomic diversity of the ceca microbiota and the expression of key immune response genes (AvBD9, AvBD10, IL-8) in laying hens. Sequencing and PCR methods were used for the analysis, which allowed us to identify correlations between specific microbiota taxa and the expression of genes associated with physiological and immune processes. It was found that the microbiota of the ceca of laying hens is characterized by pronounced differentiation in the nature of its relationships with innate immunity genes: a group of taxa that are dominant in the normal state (Actinobacteriota, Bifidobacteriaceae, and the main representatives of Firmicutes) negatively correlates with the expression of AvBD9, AvBD10, and IL8, consistent with their anti-inflammatory and immunoregulatory functions. Conversely, the positive correlations found for the genera Anaerostipes, Romboutsia, and Fournierella indicate their potential to stimulate mucosal immunity, which may be important both for maintaining colonization resistance and for the development of inflammatory responses. These findings have potential applications in optimizing the health and productivity of poultry.

The feed additive «Complisorbin» based on shungite, zeolite, lignin and glucan is intended for use in animal feed. It is known that such sorbents are used to detoxify mycotoxins and improve reproductive health, therefore, the study of their embryotoxic and teratogenic effects is an important step in preclinical evaluation. For this purpose, three groups of nonlinear white rats were formed, with 20 animals each. Animals of the first and second groups were given a suspension of the feed additive «Complisorbin» in distilled water daily from 1st to 19th day of pregnancy, at the rate of 250 and 500 mg/ kg body weight. The dosage of the feed additive was calculated individually for each animal. The third group served as biological control and received distilled water. According to the results, fetal mortality was reduced to 3,91±0,24 % (500 mg/kg) versus (6,98±0,34 %) in the control. In addition, the weight gain rates of females (103,5—105,4 g), the weight of baby rats (62,75—69,56 g by day 28) and the timing of reflexes (ear detachment 3,75—3,88 days) did not differ from the norm. Thus, the results of the study indicate the absence of embryotoxic and teratogenic effects of the feed additive «Complisorbin» in these doses in both the antenatal and postnatal periods of development of baby rats.

This article presents the results of a research and production study examining the effect of the biologically active microbial composition (BAMC) Symbion-D on milk production and the hematological status of lactating cows. BAMC Symbion-D is a multicomponent mixture of biologically active substances (metabolites) produced by a symbiotic culture of various species of yeast and acetic acid bacteria of the Medusomyces gisevii consortium, combined with pectin. Experimental studies were conducted at an agricultural enterprise in the Omsk Region engaged in the breeding and rearing of Red Steppe cattle. The study subjects were first-calf heifers, divided into an experimental (n=158) and a control (n=145) group. Cows in the experimental group were additionally administered 100 ml per head of the probiotic preparation Symbion-D daily for 70 days as part of their full-ration feed mixture during the morning feeding. Cows in the control group received only the basic diet. Results: an increase in average daily milk yield by 930 g per head, without affecting the fat and protein content of the milk; an increase in red blood cell count by 10,6 % and hemoglobin concentration by 9,5 %; an increase in total protein concentration by 14,01 %, globulin fraction by 11,24 %, creatinine by 12,54 %, and glucose by 7,67 %; an increase in alanine aminotransferase activity by 15,83 % against a background of a 19,95 % decrease in total bilirubin levels reflects adaptive processes in hepatocytes caused by improved bile flow. A microbiological study of milk showed that after 30 days of application of BAMC Symbion-D to cows, the proportion of samples with no growth of pathogenic and opportunistic pathogenic microorganisms increased from 16,7 % to 33,3 %. The culture liquid of Medusomyces gisevii in combination with pectin promotes activation of protein and energy metabolism, improves the functional state of the liver and the hematopoiesis system, which, together with an increase in productivity, allows us to consider this The composition is used as an effective metabolic corrector for cows during the breeding season.

Milk is one of the main nutritional products for both humans and mammals, as it contains many important biologically active substances. The aim of the work was to assess the basic data on the current state of dairy farming in Russia in terms of productivity and composition of cows’ milk. It is positive that in 2025, the volume of raw milk production (VRP) in Russia amounted to ~34,1—34,3 million tons (5,6—5,8 % higher than in 2021) and has been steadily increasing over the past 20 years. Along with the growth of VRP in recent years, the share of three types of «dairy» farms: 1. Large Agricultural Organization (LAO); 2. Private Farms (PrFs); 3. Peasant Farms (PeFs) is also changing: 1. LAO — 63,8 % (56,2 %); 2. PrF — 28,4 %; (34,7 %); 3. PeF — 7,8 % (9,1 %) for 2025 (2021), i.e., LAO are regaining their leadership position against the backdrop of a decreasing share of PrFs and PeFs. In terms of total livestock numbers, the Black-and-White and Holstein breeds are clearly in the lead, followed in descending order by Simmental, Kholmogory, Red-and-White, Red Steppe, Ayrshire, Yaroslavl, and other breeds. The Holstein breed has the highest total milk yield per lactation, followed in descending order by Black-and-White, Yaroslavl, Ayrshire, Kholmogory, Red Steppe, Red-andWhite, and Simmental. The Simmental and Yaroslavl breeds shared first place in fat content (4.1%), followed in descending order (to 3,8 %) by Holstein, Red Pied, Red Steppe, Ayrshire, Black Pied, and Kholmogory breeds. The Simmental and Yaroslavl breeds shared first place in protein content (3,3 %), followed in descending order (to 3,1 %) by Black Pied, Red Pied, Red Steppe, Ayrshire, Holstein, and Kholmogory breeds.

The sable of the black Pushkin breed is a typical representative of the marten family, possessing a number of morphofunctional adaptations due to the predatory type of diet and environmental features. Fur farming remains an important branch of domestic animal husbandry, and the growing interest in intensive breeding of this species necessitates an in-depth study of the morphological features of its internal organs and vascular system. The importance of the digestive process in animals cannot be overestimated, since it provides the body with the necessary plastic and energy resources through a complex chain of hydrolytic, motor-evacuation and absorption mechanisms. The aim of the study was to study the ways of forming branches of the cranial mesenteric artery and to provide detailed morphotopic and morphometric characteristics of intestinal arteries in this species of fur–bearing animals. The analysis of the presented morphometric data on the age-related features of the course and branching of the cranial mesenteric artery in male and female sables of the black Pushkin breed makes it possible to identify clear patterns of growth of all the studied structures with age, as well as minor sex differences. The revealed age-related dynamics of vascular diameter is biologically appropriate and is associated with an increase in metabolic needs, intestinal volume and the completion of the structural formation of its bloodstream. It was found that the cranial mesenteric artery departs from the abdominal aorta at the level of the second and third lumbar vertebrae. From the cranial mesenteric artery sequentially depart: the caudal pancreatic-duodenal artery, the common trunk of the right colon, middle colon and iliac-colon arteries, as well as eight to twelve arteries of the jejunum. The final branch is the ileo-intestinal artery, anastomosing with the ileo-colon artery. Changes in the main and dichotomous type of vascular branching in the jejunum wall are described. The features of vascularization of the ileumcolon transition zone due to the absence of a cecum in representatives of the marten family are noted.

The primary objective in increasing pig farming productivity is to produce healthy offspring and ensure their safety. To achieve this, particular attention should be paid to the role of the placenta in ensuring the full realization of the genetic potential of newborn animals. This article presents the results of a study of the structural and functional characteristics of the fetal portion of the domestic pig placenta, which determine the viability of neonatal piglets. The study focused on the fetal portions of pig placentas and newborn piglets. A combination of morphological, clinical, and zootechnical methods was used. The total fetal portion of the sow’s placenta consists of individual fetal portions of the placentas for each fetus. In a single litter, sows give birth to several piglets with different morphofunctional statuses and viability. The weight and area of individual fetal portions of the placenta correlate with the weight of the newborn piglet, as well as the length of the umbilical cord. The fetal parts of the placenta with a well-developed folded chorion covered with numerous villi collected in nodules, pink-red, without signs of significant vascular congestion, maximum parameters of weight and area (288,67±10,26 g and 584,05±42,50 cm2, respectively), the shortest umbilical cord length (3,88±0,70 cm) determine the birth of piglets, the survival rate of which at weaning reaches 100 %. The fetal parts of the placentas in which congestive vascular phenomena, infarctions of the chorionic surface, multiple avilable areas on the chorion are detected, as well as the smallest macromorphological parameters, but the greatest umbilical cord length determine the birth of prenatally underdeveloped piglets. Such newborns have a live weight not exceeding 614,44±30,96 g, a body length of 24,00±1,00 cm, and realize the food dominant only after 20,89±0,72 minutes, and the locomotor dominant — 12,22±0,57 minutes after birth.

Metabolic liver pathologies are increasingly being recorded in carp broodstock under intensive pond fish farming conditions; however, objective intravital diagnostic criteria for their diagnosis have not yet been developed. The aim of this study was to quantitatively evaluate the morphometric parameters of peripheral blood erythrocytes in female common carp (Cyprinus carpio) with verified fatty liver disease and compare these characteristics with those of clinically healthy individuals. The study was conducted at the Laboratory of Innovative Recombinant Proteomics Preparations in the Department of Experimental Pharmacology and Modeling of Living Systems at the All-Russian Veterinary Research Institute of Pathology, Pharmacology, and Therapy. Field research and material collection were conducted at Zazerkalye LLC in the Anninsky District of Voronezh Oblast in 2024-2025. Two experimental groups were formed: the experimental group (n=50) included individuals with confirmed fatty liver disease and the control group (n=50) included clinically healthy individuals with no signs of liver pathology. Statistical processing of the obtained data was performed using a package of applied software for statistical analysis. The normality of the distribution of quantitative characteristics was preliminarily checked using the Shapiro-Wilk criterion. Since some morphometric parameters did not correspond to the normal distribution law, the results were presented as the arithmetic mean (M) ± standard error of the mean (m). The reliability of intergroup differences was assessed using the nonparametric Mann-Whitney U-test for independent samples. Differences were considered statistically significant at p<0.05. Smears stained according to Pappenheim showed that fish with liver damage lose the morphological homogeneity of their red blood. The combination of anisocytosis, cytoplasmic vacuolization, and nuclear deformations forms a stable morphological pattern pathogenetically associated with dystrophic changes in hepatocytes. The obtained results substantiate the potential of incorporating peripheral blood morphometry into the intravital diagnostics of metabolic hepatopathies in carp broodstock on commercial farms.

The search for new safe non-medicinal methods of influencing the incubation of farm bird eggs remains an urgent topic in the scientific community to this day. One of these is the use of a certain spectrum of light during incubation. To date, most of the studies conducted on the effect of the light factor relate to the post-incubation ontogenesis of poultry. This article is a fragment of a scientific study devoted to the study of the effect of red monochromatic illumination on liver morphogenesis in turkey embryos. The aim of the study was to determine the dynamics of changes in the area of liver hepatocytes in turkey embryos during different incubation periods under the influence of the light factor. During the entire incubation period of the turkey egg, LED lighting sources in the red range of the spectrum were used in the experimental group. The control group was incubated without lighting. The embryonic liver was obtained from 13, 15, 17, 19, 21, 23, 25, 27- day-old turkey embryos. The area of hepatocytes was determined on histological preparations. Analysis of the results showed that the dynamics of changes in the area of liver cells in both groups was undulating with a tendency to increase the area of hepatocytes by the end of incubation – 27 days, when the area of hepatocytes in the control and experimental groups was almost at the same level with a difference of 0,7%, in favor of the experimental group. The lowest value of the area of hepatocytes during the observation period in the control group was recorded at 17 and 19 days of age, and in the experimental group at 19 days of age. The maximum area of liver cells in both groups was observed at the age of 27 days. The data obtained contribute to understanding the mechanisms of photoregulation of liver tissue growth.

The immune system is one of the most sensitive targets of the stress response, as reflected by alterations in lymphoid organs and hematological parameters. Paracetamol, one of the most widely used analgesics, is traditionally studied as a hepatotoxic agent; however, its effects on immunohematological parameters remain insufficiently explored, especially in combination with chronic stress. The aim of the study was to assess the effects of 28-day administration of paracetamol (1000 mg/kg), including under conditions of chronic unpredictable stress, on body weight, thymus and spleen weight coefficients, and hematological parameters in male and female rats. In males, chronic stress caused a significant decrease in leukocyte count (to 5,7×10⁹/L; p=0,001), whereas paracetamol increased leukocyte levels compared to stress alone (p=0,001). Paracetamol reduced hemoglobin levels (129,5 g/L), while in combination with stress, hemoglobin was increased (141,1 g/L; p=0,001). In females, these changes were not observed; however, a significant decrease in platelet count was detected in all experimental groups (p=0,001). The thymus weight coefficient in females decreased after paracetamol administration (1,08; p 0,01), whereas in males it remained unchanged. A reduction in spleen weight coefficient was observed only in males under stress and combined exposure (p≤0,02).The data indicate a sex-dependent pattern of immunohematological changes associated with paracetamol administration, both alone and in combination with chronic stress. At the same time, the absence of endocrine parameter assessment does not allow the observed differences to be unequivocally interpreted as evidence of a stress-protective effect of paracetamol; these findings require further investigation with the inclusion of markers of hypothalamic-pituitary-adrenal and gonadal regulation.

Including rapeseed in broiler diets increases protein levels without increasing feed volume. However, anti-nutritional components of rapeseed can affect blood morphological parameters: glucosinolates suppress thyroid function, indirectly affecting erythropoiesis, while phytic acid impairs the absorption of iron and copper, which are necessary for hemoglobin synthesis. Therefore, this analysis is necessary to assess the physiological state of birds when adding rapeseed at various doses. The aim of this study was to examine blood morphological parameters after replacing specific protein components in the broiler chicken diet. A 10 % feed replacement did not significantly alter blood morphological composition; basophil counts decreased by 20,7 %, which may positively impact the immune status of broiler chickens. Replacing 25 % and 50 % of the feed weight with rapeseed in the diet resulted in a 41,2 % and 32,3 % reduction in white blood cell counts, respectively. However, these values are within reference limits and therefore cannot be considered a symptom of abnormalities. Eosinophil counts increased in experimental groups 3 and 4 by 48,1 % and 36,4 %, respectively, which remains within physiological norms and can only indirectly indicate an inflammatory process in the bird’s body. To develop practical recommendations for feeding broiler chickens with rapeseed supplements at various dosages, a comprehensive assessment of morphological parameters, blood biochemistry, and chyme analysis is necessary.

Equine gastric ulcer disease is a widespread condition affecting up to 90% of sport horses, characterised by erosive lesions of the gastric mucosa and chronic inflammation. Standard therapy with proton pump inhibitors (omeprazole) reduces gastric acidity but does not address the underlying immune dysregulation driving disease chronicity. An imbalance of cytokines — elevated pro-inflammatory mediators (tumour necrosis factor alpha — TNFα, interleukin-1β — IL-1β, interleukin-6 — IL-6) alongside reduced anti-inflammatory signals (interleukin-4 — IL-4, interleukin-10 — IL-10) — is considered a key pathogenic mechanism. The aim of this study was to evaluate the efficacy of targeted anti-cytokine therapy with antiTNFα monoclonal antibodies as an adjunct to standard gastric ulcer disease treatment. Thirty horses with endoscopically confirmed gastric ulcer disease were divided into a control group (omeprazole 4 mg/kg/24 h, n=15) and a study group (omeprazole 4 mg/kg/24 h plus a single intravenous infusion of anti-TNFα monoclonal antibodies 5 mg/kg, n=15). Serum cytokine levels (TNFα, IL-1β, IL-6, IL-4, IL-10) were measured by enzyme-linked immunosorbent assay (ELISA) at baseline, 6 h, 24 h, and 8 days. In the study group, rapid and pronounced suppression of pro-inflammatory cytokines was recorded: TNFα decreased by 96% at 24 h, IL-1β by 82%, and IL-6 by 80% (p < 0.001). Simultaneously, anti-inflammatory responses increased: IL-4 and IL-10 rose by 75% and 68%, respectively, by day 8. The TNFα/IL-10 ratio declined 50-fold, indicating restoration of immune homeostasis. No significant cytokine dynamics were observed in the control group. Targeted anticytokine therapy with anti-TNFα monoclonal antibodies represents a promising immunomodulatory approach to gastric ulcer disease treatment, addressing an existing therapeutic gap.

The article highlights the results of a study of the morphological parameters of the liver in the age aspect of 1-, 10-, 20-, 30-, 40-, 50- diurnal quails of the Pharaoh breed, as well as organ changes, taking into account the addition of the probiotic Vetom 1,2 and the multivitamin complex Chiktonik to the basic diet. The aim of the work was to establish the effect of the probiotic Vetom 1,2 and the multivitamin complex Chiktonik on the postembryonic organogenesis of the liver of Pharaoh quails. During the research, the effect of the probiotic drug «Vetom 1,2» and the multivitamin complex «Chiktonik» on the growth and development of the wall digestive gland of Pharaoh quails was revealed. It was found that the highest relative liver weight of quails was observed at the age of 30 days (especially among birds of the 1st experimental and control groups), and then there was a gradual decrease in this indicator (by 1,30 %). The relative weight of the 2 experimental groups was approximately the same throughout the study (from 3,10 % at 10 days of age to 2,90 % at 50 days). The absolute mass of the liver progresses markedly from 10 days to 50 days of age, and in birds of the experimental groups it reaches its maximum on day 50. It is also worth noting that the birds of the control group (up to 40 days of age) were the leader in absolute liver mass for most of the experiment. The parameters of the right and left lobes of the liver have pronounced differences, starting from the age of 30 days in quails. Birds from the group that received only mixed feed showed better development of the left lobe, but the parameters of the right lobe were not much smaller. In quails from the 1st experimental group, the left lobe significantly prevailed over the right, while in quails from the 2nd experimental group, on the contrary, the right lobe was better developed than the left.

Quaternary phosphonium salts are promising compounds due to their high lipophilicity and membranotropic activity, but data on their chronic toxicity are limited. The aim of the research was to conduct a histological assessment of the chronic toxicity of 3-(decyloxy)-3-oxopropyl triphenylphosphonium chloride with prolonged oral administration. The study was performed on 24 sexually mature white rats (males and females), divided into 4 groups. Animals received a 1 % solution of the compound intragastrically for 30 days at doses of 18,67, 46,67 and 93,34 mg/kg (1/50, 1/20 and 1/10 of LD50). The control group received distilled water. Clinical observation and body weight assessment were performed. After euthanasia, necropsy and histological analysis of organs (liver, lungs, heart, stomach, kidneys, adrenal glands) stained with hematoxylin and eosin were performed. During the experiment, animals of the experimental groups showed a temporary decrease in appetite, and at the maximum dose, a slight loss of body weight and alopecia. Histological analysis showed that the compound in doses up to 93,34 mg/kg does not cause dose-dependent pathological changes in the heart, liver, kidneys, adrenal glands and stomach. The structure of the myocardium, hepatocytes, and nephrocytes remained intact. Background bronchoassociated lymphoid tissue (BALT) and slight thickening of the interalveolar septa were observed in the lungs of all groups, including the control group. In the group with the maximum dose, some animals showed moderate interstitial changes (infiltration by mononuclears and neutrophils), but there were no statistically significant differences from the control (p>0,05), which was regarded as an individual variation against the background of a chronic experiment. It was found that the investigated quaternary phosphonium salt in the studied dose range does not have a systemic toxic effect on parenchymal organs. The revealed pulmonary changes are of a background nature and are not associated with a dose-dependent effect, which justifies the prospects for further study of the compound for practical use.

One of the common metabolic disorders in high-yielding animals is ketosis in dairy cows, which is accompanied by an increase in toxic substances in the blood of pregnant cows, and in newborn calves can manifest as a whole range of metabolic disturbances. The aim of this study is to evaluate the morphobiochemical blood parameters of calves born to clinically healthy heifers and those with signs of subclinical ketosis in Holstein breed. Two groups of Holstein calves aged four days were formed at a specialized farm in the Kostroma region: Group 1 (control) — calves born to healthy heifers (n=10), Group 2 (experimental) — calves born to heifers with signs of subclinical ketosis (n=20). In samples of venous blood from the calves, hematological and biochemical parameters were determined: the number of erythrocytes, hemoglobin, platelets, leukocytes and their fractions, MCV, MCH, MCHC, RDW, MPV indices, hematocrit, ESR, levels of ketone bodies, and glucose; in serum, the levels of total protein, albumin, globulins, albumin-globulin ratio, total, direct, and indirect bilirubin, creatinine, triglycerides, cholesterol, urea, and enzymatic activity of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and gamma-glutamyltransferase, as well as the De Ritis ratio were determined. The numerical data were processed using variance statistics with the MS Excel program. Based on the conducted research, it was established that on the 4th day after birth, calves born to Holstein heifers with signs of subclinical ketosis showed changes in their hematological and biochemical profiles: a higher level of ketone bodies in the blood, statistically significant differences in the leukogram of the calvespredominance of lymphocytes and a higher level of monocytes; lower protein content, with significantly higher values of the albumin-globulin ratio and low levels of globulin fraction proteins against a backdrop of high creatinine concentration in the blood. The enzymatic activity in the blood of calves from affected heifers was characterized by higher levels of ALP, GGT, and ALT, with significantly lower values of the De Ritis ratio.

The article presents the anatomical features of the posterior femoral and gluteal hip extensor groups in the sable. Layer-by-layer mutual arrangement of these muscles and points of their fixation on bones of pelvic extremity are established. A layer-by-layer arrangement of the structures of the pelvic limb of the sable was established. The places of fixation of the studied muscles, the functions performed by the muscles and their belonging to a certain type of muscles are determined. It is shown that the sable has no caudal abductor of the lower leg, and the caudal muscle is subject to significant regression and becomes a synergist of the biceps femoris. The material for the studies was sectional material — pelvic limbs (n = 16), selected from the sable, without external signs of pathologies of the musculoskeletal system. The identified anatomical features of these muscles may reflect their functional relationship, are reference in assessing the structural and functional state of the muscles of the posterior femoral extensor group in the sable.

The aim of this study was to clarify the sources of venous outflow from the esophagus, crop, and gizzard in the Hisex White chicken, as well as to establish patterns of venous branching within them. Five 160-dayold Hisex White female chicken carcasses served as the study material. Dissection and the preparation of cleared specimens were used to study the birds’ venous system. Three birds were used to prepare angio-osteotopic specimens using Redont acrylic resin with the addition of oil paints for venous morphometry. We established that all the veins of the esophagus, crop, and gizzard in chickens form a single hemodynamic system, which is subdivided into main veins (right and left jugular veins), extraorgan veins (ascending and descending esophageal veins, dorsal and ventral proventricular veins), and intraorgan veins. Venous drainage from the esophageal walls occurs through 5—7 branches, which enter the ascending and descending esophageal veins and then the corresponding jugular veins. Venous drainage from the crop occurs through the right, left, and ventral crop veins. The veins of the chicken’s glandular stomach are represented by superficial and deep venous vessels. The superficial veins—the proventricular, dorsal, and ventral veins, located on its respective surfaces-drain blood from the glandular stomach, while the deep veins, where a powerful submucosal plexus forms in the form of reticular, transverse, and arcuate anastomoses, drain water-soluble substances into the venous blood. The glandular stomach has an oval-elongated shape, therefore, in the branching of the venous vessels, a characteristic structure is observed in the form of rounded cells, which have the same thickness throughout the entire length of the organ in accordance with the flow of transorgan blood flow.

Quail farming is one of the promising areas of industrial poultry farming. This study is devoted to a comparative analysis of the early stages of embryogenesis of quails of three breeds of different productivity trends (Japanese — egg, Estonian — meat-egg, Radonezh — meat). The work used embryos of different incubation periods: 12, 24, 36, 48, 60 and 72 hours. The eggs were opened after preliminary morphometry. An adapted «Early Chick, EC» technique was used to better visualize the early stages of embryogenesis. In the course of the research, discrepancies in the rates of embryogenesis were established: Japanese quail embryos show the most accelerated rate of development, ahead of the Estonian and Radonezh breeds at stages 1-2 and 2-3, respectively, on the Hamburger—Hamilton scale. The main differences can be observed already in the first 12 hours: Japanese quail embryos show a more active rate of development. However, by the 72nd hour of incubation, a gradual convergence of development rates is observed in all three breeds. At the same time, 100 % and 60 % of the embryos of Japanese and Estonian breeds, respectively, are at the 18th stage. In 40 % of cases, Radonezh quails correspond to the 18th stage, and 60 % correspond to the 17th stage of development. The revealed patterns and breed-specific differences can contribute to the development of differentiated incubation regimes and the establishment of critical marker points during the early periods of embryonic development.

The article presents the results of studying morphofunctional changes in the reproductive organs of Yakutian mares at different stages of the estrous cycle. The research was conducted in Central Yakutia (Namsky District) on the basis of a farm during the spring–summer period. The study involved 14 clinically healthy mares aged 4 to 6 years kept under year-round pasture–herd management typical for Yakutian horse breeding. Additionally, a morphometric examination of the reproductive organs of a newborn filly was performed. The work included two stages. At the first stage, vaginal examination using a speculum was carried out to assess the condition of the mucous membranes of the vaginal vestibule and vagina, the nature of secretions, and the degree of cervical opening. At the second stage, after the animals were slaughtered, linear measurements and weighing of the organs were performed: the length of the vestibule and vagina, the length of the cervix, the length and width of the uterine body, the length of the uterine horns and oviducts, as well as the length, width, thickness, and weight of the ovaries were determined. The number and size of follicles and the presence of corpora lutea were recorded. The obtained data were processed using variation statistics. In the equilibrium stage, the mucous membranes were pale pink and dull, and the cervix was closed. The length of the vaginal vestibule was 6,63±0,18 cm, the vaginal length was 23,93±0,58 cm, and the vaginal weight was 456,6±22,45 g. The uterine body length was 10,2±1,05 cm, width — 7,1±0,15 cm, and uterine weight — 907,0±38,1 g. The ovaries were bean-shaped: the right ovary measured 5,43±0,23 cm in length and weighed 30,0±2,08 g; the left ovary measured 4,93±0,08 cm and weighed 26,6±1,2 g. Follicles with a diameter of 1,0—1,5 cm and corpora lutea of the estrous cycle were detected in the ovaries. In the excitation stage, the mucous membranes were hyperemic and shiny, the cervix was open, and clear mucus was observed. The length of the vaginal vestibule increased to 7,20±0,17 cm, the vaginal length to 26,53±1,02 cm. The uterine body length increased to 13,63±0,58 cm, width to 7,33±0,12 cm, and uterine weight reached 995,00±16,62 g. The ovaries became pear-shaped or spherical, and their weight increased to 37,66±1,45 g (right) and 35,66±3,71 g (left). Follicles with a diameter of 3,5—4,3 cm were found, and in one case, a follicle with a diameter of 6,1 cm corresponding to the preovulatory stage was detected. After foaling, estrous cycles resumed on average 10,32±0,64 days postpartum. The average duration of the estrous cycle was 18,90±1,23 days. Single estrus was observed in 60 % of mares, double estrus in 28,1 %, and triple estrus in 11,4 %. The overall pregnancy rate in the herd was 76,31 %.

In order to regulate metabolism in poultry farming, a wide range of different methods and methods are offered. Special attention is paid to preparations and feed additives obtained on the basis of phytobiotics. In this regard, the purpose of these studies was to study the effectiveness of the effect of Echinacea purpurea extract in combination with the probiotic drug Subtilis-C on the biochemical parameters of blood serum in broiler chickens. The research was conducted on Cobb-50 broiler chickens in two scientific and production experiments in the Republic of North Ossetia-Alania. In the first scientific and production experiment, the optimal dose of administration of echinacea purpurea extract into the diet was established, in the second, the effectiveness of combining echinacea extract with the probiotic Subtilis-C was studied. During the second scientific and production experiment, a decrease in serum cholesterol by 27,23 % or 0,61 mol/l (P<0,05) was found, which may be a warning factor of excessive fat deposition, while the use of the tested drugs is accompanied by a significant increase in glucose by 7,23 % (P<0,05), aspartate aminotransferase (AsAt) and alanine aminotransferase (AlAt) up to 9,73 % and 7,17 %, respectively, During the experiment it was shown, It is shown that the combined use of the phytoprobiotic complex under study has a positive effect on the biochemical profile of blood serum and, in general, on the metabolic processes in broiler chickens, and also contributes to the formation of marketable carcasses. The optimal dose and regimen for broiler chickens is the administration of Echinacea purpurea extract at a dose of 5,5 mg/kg body weight in combination with the probiotic Subtilis-C at a dose of 0,3 kg/ton for pre-start and starter feeds; and 0,15 kg/ton for finishing feeds.

Molecular genetic markers, such as the polymorphism of the kappa-casein gene (CSN3), are a important tool for increasing the efficiency of dairy cattle breeding. The aim of this study was to investigate CSN3 polymorphism in a Holstein cattle population and to assess its associations with blood biochemical parameters reflecting the animals’ metabolic status. In the studied herd (146 animals), allele (A — 0,651, B — 0,349) and genotype frequencies were determined using the PCR-RFLP method: AB (47,9 %; 70 animals), AA (41,1 %; 60 animals), and BB (11,0 %; 16 animals). The results of the biochemical analysis for 12 blood serum parameters were statistically processed using t-test Student in the context of the identified genotypes. Significant associations of CSN3 polymorphism with the biochemical profile were revealed. Carriers of the B allele, especially those with the BB genotype, were characterized by a significantly higher level of protein metabolism indicators (total protein, albumin, urea, creatinine) and activity of enzymes from the classes of aminotransferases (AST, ALT) and hydrolases (alkaline phosphatase), as well as lower concentrations of bilirubin and glucose compared to animals with the AA genotype. The obtained data indicate more intensive metabolism and efficient liver function in cows with the B allele. The results confirm the pleiotropic effect of the CSN3 gene, linking the genetic variant not only to milk quality but also to the body’s metabolic profile. This substantiates the feasibility of using this gene as a marker for the comprehensive assessment and prediction of metabolic adaptation in Holstein cattle breeding programs. The work was carried out according to a state assignment, registration number 125031003428-9

The transition from classical to genomic selection is of strategic importance for the poultry industry of the Russian Federation. Genes involved in the regulation of the reproductive system are of particular significance for productivity. The aim of the study was to analyze the dynamics of the expression levels of the ESR2 and PTHLH genes in the ovarian tissues of hens of the SM9 original line of the «Smena 9» cross at key stages of post-embryonic development. The research material consisted of ovarian tissues collected from birds of various age groups. The evaluation of the relative gene expression level was performed in the ovarian tissues of birds from four age groups using quantitative real-time PCR with the ΔCt method. The expression of the ESR2 gene in the ovary varied significantly. The maximum activity level was recorded during the phases of postnatal adaptation (week 2) and ovarian activation (week 10). With the onset of puberty, the expression steadily decreased, reaching a minimum by the active egg-laying phase at week 27. The dynamics of PTHLH were more gradual: stable expression in the early periods of development was followed by a significant decrease in activity exclusively during the active egg-laying stage. The regulation of ESR2 and PTHLH gene expression is stage-specific. High gene activity in the early stages ensures follicle morphogenesis. The subsequent decrease in transcription is physiologically associated with the onset of egg-laying. It is advisable to use the identified genes affecting the development of the reproductive system in hens as candidates for the study of single nucleotide polymorphisms within the framework of marker-assisted selection.

The article presents the results of a comprehensive study on the impact of the degree of «Swissbreeding» (upgrading) on the realization of the life potential of Kostroma cows at the breeding plant. A retrospective analysis of lifetime performance indicators of 432 cows from the «Karavaevo» breeding plant (Kostroma region) was conducted. Animals were stratified into four groups based on the percentage of Brown Swiss blood: low (≤50 %), medium (51—75 %), high (76—88 %), and very high (>88 %). Statistical data processing was performed in the R environment using Spearman’s rank correlation analysis, Kruskal-Wallis test, and linear regression modeling. A statistically significant negative correlation was established between the share of improving breed blood and life span (rs=-0,25; p<0,001), as well as total lifetime milk yield (rs=-0,15; p<0,01). It was revealed that animals with low blood percentage (≤50 %) possess the best economic and biological characteristics, with a median lifetime yield of 32232 kg, which is significantly higher than in other groups. High-grade crosses implement a «sprinter» productivity model, demonstrating a high Milk per Day of Life index (MDL≈13,66 kg), but are characterized by early culling. The constructed regression model proved that 80 % of the variation in lifetime productivity is driven by the time factor, with each additional day of life increasing the total yield by 16,6 kg. A decrease in butterfat content from 4,17 % in low-blood cows to 4,05 % in high-blood animals was also noted. The strategy of upgrading crossing (top-crossing) under the conditions of this herd is recognized as inefficient. To maximize gross milk production and preserve the adaptive qualities of the Kostroma breed, it is recommended to maintain the share of Brown Swiss blood at a level of no more than 50—75 %.

To identify correlations between serum progesterone concentrations in mares, corpus luteum area, and blood flow parameters in the corpus luteum using Power-Mode Doppler Doppler images, a study was conducted in natural cycles and cycles with induced luteolysis. A comparison of visual blood flow assessment and the results of a computerized image analysis system using ImageJ was also conducted. Ultrasound examinations were performed on 10 mares from the experimental stable of the All-Russian Research Institute of Equine Breeding. Using computer analysis of corpus luteum Doppler images, the above characteristics were determined during the following periods: days 0—4, 5—7, 8—12, and 13—16 of the mares’ estrous cycle (day 0 is ovulation day). Statistical processing of the data was performed using Excel and Statistica 12. Differences between periods were assessed using the nonparametric Mann-Whitney U-test with a significance level of p < 0.05. Processed data by period are presented as the median (M) and upper and lower quartiles (LQ-UQ). The relationship between parameters was calculated using the Spearman correlation coefficient. Analysis of the correlation coefficient revealed a moderate positive relationship between serum progesterone concentration and blood flow area and the blood flow intensity score (r=0,33 and r=0,3; p<0,05). A strong positive relationship (r=0,7—0,8; p<0,05) was established between the assessment of blood flow parameters using a computer analysis system (ImageJ) and the visual assessment of blood flow score. During induced luteolysis, a strong positive correlation (r=0,82; p<0,05) was found between progesterone concentration and corpus luteum area, and a significant positive correlation (r=0,66; p<0,05) was found between corpus luteum area and blood flow area. These data may have useful prognostic value when assessing the functional activity of the corpus luteum in mares.

Holsteinized black-and-white cows aged 4—5 years were studied in the conditions of a peasant farm and a large agricultural enterprise in the Udmurt Republic. A total of 40 cows were examined at each enterprise, subdivided into 4 groups of 10 cows each. The first group included newly-calved cows; the second group included grassy animals but not tested for pregnancy; the third group included pregnant cows at different stages; and the fourth group included open cows. Rectal and ultrasound examinations, biochemical blood tests. Despite a comparable prevalence of limb diseases and mastitis (23,1—24,9 %), the disease structure exhibited significant inter-farm variations. Obstetric and gynecological diseases predominated in the small-scale farm (40,0 %), whereas metabolic disorders (18,5 %) and gastrointestinal pathologies (16.4 %) were more prevalent in the large-scale agricultural enterprise. Gynecological screening of fresh cows in the small-scale farm revealed uterine subinvolution (10 %) and metritis (30 %); in the large-scale enterprise, metritis was recorded in 40 % of the animals. Among open (nonpregnant) cows in the small-scale farm, luteal cysts (60 %) and chronic metritis (40 %) were diagnosed, while the industrial complex showed luteal (80 %) and follicular (20 %) cysts. Comparative analysis identified inter-farm variability in the metabolic status of the cows. In the small-scale farm, hyperproteinemia and increased globulin fractions were established (p≤0,05); combined with high alkaline phosphatase activity (p≤0,05) in open cows, this indicates the synergistic impact of unbalanced nutrition and chronic hepatobiliary disorders. In the industrial complex, urea concentrations in all groups significantly exceeded the values of the small-scale farm (p≤0,05), reaching a peak alongside a concurrent albumin deficiency (p≤0,01—0,02). This metabolic pattern indicates an excess of rumen-degradable protein in the diet, which determines a high incidence of ovarian cysts and increases the risks of embryo implantation failure.

The aim of the study was to evaluate the effectiveness of protocols for the use of various adjuvants in epidural anesthesia for dogs undergoing different surgical interventions. The research was conducted at the VetDoktor Veterinary Clinic in Novosibirsk from 2024 to 2025. It included 102 dogs (age 1—10 years, weight 5—40 kg, ASA I—II) for planned and emergency surgeries requiring anesthesia of the caudal body part. Exclusion criteria: contraindications to epidural anesthesia, allergies to drugs, systemic pathologies. Animals underwent clinical examination, blood tests, and echocardiography. They were divided into 6 groups of 17 individuals each: control (bupivacaine 0,5 % without adjuvants), groups with morphine, fentanyl, dexmedetomidine, ketamine, and a triple combination. The epidural puncture technique included animal positioning, field preparation, identification of landmarks, insertion of the Tuohy needle, and administration of solutions at a rate of 1 ml/30 sec. Results demonstrated the effectiveness of adjuvants depending on the type of surgery. For orthopedic interventions on the hip joint, bupivacaine + morphine or the triple combination are optimal for prolonged analgesia. On the knee joint, bupivacaine + ketamine for antihyperalgesic effect. For abdominal operations (ovariohysterectomy, intestinal surgery), ropivacaine + dexmedetomidine or bupivacaine + fentanyl. For the urinary system, bupivacaine + ketamine without urinary retention. Recommendations consider surgery duration, patient risk, with dose adjustments for ASA III, geriatric, and other groups. Economic analysis revealed the highest effectiveness of ketamine (107,8 rub./hour analgesia) and dexmedetomidine (95,6 rub./hour).

Soft tissue sarcoma is a fairly common oncological disease in cats, which is more likely to occur as a result of trauma, including injections. This type of tumor is characterized by an aggressive course and pronounced infiltrative growth, with a relatively low metastatic potential, which makes local control of the disease a subject of study. In the veterinary clinic of Baiga in Saratov, a clinical examination was performed on a 14-year-old cat with soft tissue sarcoma. Comprehensive clinical examinations were conducted to diagnose the neoplasm, which included a visual assessment of the animal’s condition, a palpation of the affected tissues, a cytological examination, an ultrasound scan of the abdominal cavity for the presence of metastases, and an X-ray scan of the chest cavity. The general condition of the animal was assessed as satisfactory: activity was reduced, lameness was present, appetite was preserved, consciousness was clear, visible mucous membranes were pink, superficial lymph nodes were not enlarged, body temperature was within the physiological norm, there was no shortness of breath, the heart rate was clear, even, and the pulse was of good fullness. According to the results of a general blood test, an increase in platelets was detected to 573.0±8.23 x109/l, which is higher than the reference values by 60 units. and thrombocrit by 0.038%, the increase in these indicators is most likely due to a neoplasm. The cytological examination revealed cellular structures characteristic of sarcoma with giant multinucleated cells. Based on the diagnostic results, it was decided to perform surgical intervention to remove the neoplasm and amputate the limb.

Pathological tooth resorption can be initiated by a variety of factors, acting both individually and in combination. The publication presents a morphological picture of the condition of teeth of all generations, subjected to different types of resorption (physiological and pathological) of the root system in dogs. The study was conducted at the of the Department of Animal Diseases and Veterinary and Sanitary Examination of the Federal State Budgetary Educational Institution of Higher Professional Education Vavilov University and the Department of Anatomy and Histology of Animals named after Prof. A.F. Klimov, Moscow State Academy of Veterinary Medicine and Biotechnology — MVA by K. I. Skryabin, as well as the Central Veterinary Clinic on Moskovskaya, (Saratov). The object of the study were dogs of various age groups (from 7 months to 8 years). The material for the study was deciduous (n=50) and permanent teeth (n=70), which were extirpated for dental indications. Based on odontoscopic and microscopic examination of the extirpated teeth, it was established that physiological and pathological resorption affect the structural organization of the dental system in dogs. This process proceeded similarly in the animals we studied. Thus, in the initial stage, small cavities form, which subsequently increase in size and merge, thereby forming larger cavities. While physiological resorption in primary teeth leads to root resorption and loss under biomechanical stress (chewing, playing), in permanent teeth, this process causes irreversible thinning of the dental tissues of the root system, leading to complete tooth loss. All types of resorption were always recorded at the root margins and the cervical dentin in the dogs we studied.

The article describes a clinical case of bilateral ureteral ectopia in a 9-year-old male Siberian Husky that was admitted to a veterinary clinic with polyuria and polydipsia for evaluation. A comprehensive diagnostic approach was used, including the collection and review of medical history, a general clinical examination, laboratory analysis of blood and urine samples, spectral analysis of renal calculi obtained during nephrotomy, a pathomorphological examination of the testes, and additional instrumental methods such as ultrasonography and abdominal computed tomography. As a result of the examination, a combination of pathologies affecting the urinary and reproductive systems was identified, including bilateral intramural ectopia of the ureters and nephrolithiasis complicated by hydronephrosis, as well as benign prostatic hyperplasia and a testicular neoplasm in the left testis. A notable feature of this clinical case is the patient’s age (9 years and 10 months) at which clinical signs of ureteral ectopia were detected. Statistically, this pathology typically manifests and is diagnosed at an earlier age, usually before one year. It is worth noting that, in this case, the sensitivity of computed tomography was higher than that of ultrasonography for diagnosing nephrolithiasis, detecting changes in the testicular parenchyma, and determining the location of the ureteral orifice.

Studies show that 30—37 % of calves are born in a hypoxic state, with the prevalence of antenatal hypoxia in dairy calves reaching 23—25 %. Literature suggests that fetal and neonatal hypoxia is the primary cause of mortality and neonatal diseases. However, data on the incidence of morbidity in calves exposed to antenatal hypoxia are lacking in the available domestic and international literature. The aim of this study was to evaluate the incidence of gastrointestinal and respiratory diseases in calves exposed to antenatal hypoxia and to determine the relationship between these morbidities. The experiment was conducted at a dairy production facility. The subjects of the study were newborn calves (n=44) of the Red-and-White breed, sired by clinically healthy cows and cows at risk for fetal hypoxia. The hemoglobin (Hb) level in maternal cows was used as a differential criterion determining the risk of fetal hypoxia. The paper presents the results of a study of morbidity in calves that suffered antenatal hypoxia. The object of the study were newborn calves (n=44) of the Red-and-White breed, obtained from clinically healthy cows and cows with anemia. It was found that they are 50,6 % more likely to develop gastrointestinal diseases and 68,6 % more likely to develop respiratory diseases. A significant positive correlation was found (r=0,50, P˂0,05) between anemia in cows and the risk of developing gastrointestinal and respiratory pathology in calves, as well as between gastrointestinal and respiratory pathology (r=0,63, p˂0,05). This gives reason to assume that respiratory diseases in animals are a consequence of the cumulative effect of residual pathological phenomena after antenatal hypoxia and gastrointestinal pathology.

The article presents the results of studies on the distribution of ophthalmopathies in the city of Kostroma in 2022—2025, depending on the seasonality, species, and breed predisposition. The aim of the study was to investigate the prevalence of ophthalmic diseases in the city of Kostroma, taking into account seasonality, species, and breed predisposition. The study was based on statistical data from automated information systems such as VetManager and Yenot, as well as logs for registering sick animals (Form No. 1-vet) from 2022 to 2025, from veterinary clinics such as OGBU «Kostromskaya gorsbzh», «Lapka», «Doktora Zorina», and «Aybolit» Veterinary Center. A total of 70352 case histories were studied and analyzed, of which 23420 (33,28 %) were surgical pathologies. It was found that 730 cases were attributed to dogs and cats with eye diseases, including 3,1 % of the total number of surgical cases. The most common eye diseases in small pets are conjunctivitis, keratitis, corneal ulcers, and, to a lesser extent, lacrimal gland prolapse, entropion, and panophthalmitis. The number of identified nosological units of eye diseases is largely determined by the quality of the diagnostic tests performed. A clinical examination by an ophthalmologist allows for the identification of a greater number of nosological units compared to a general practitioner. In dogs, ophthalmopathies are most commonly observed in purebred animals (52,10 %), while in cats, they are more common in mixed-breed animals (70,60 %). Among dogs, brachycephalic breeds, such as pugs, Pomeranians, French Bulldogs, Yorkies, Chihuahuas, and Pekingese, are particularly susceptible. A significant number of eye disease cases in dogs occur in the spring (31,0 %) and in cats in the summer (31,1 %), while the minimum number occurs in the autumn (16 %) and (18 %), respectively.

The aim of the study was to analyze the adaptation of the cardiovascular system of service dogs to the loads of the search and rescue profile, based on the data of echo and electrocardiographic studies. The study included clinically healthy dogs of medium breeds of the search and canine service, divided into two groups. The animals of the first group participated in the normalized, and the animals of the second group in the non-normalized search and rescue operations. There were 10 animals in each group that had no significant health abnormalities according to the clinical examination. EchoCG was performed on the Mindray DC-8 Exp device using a sector phased and microconvex sensor. The ECG was recorded using a Poly-Spektr-8/V device using the standard lead method, and the ECG was taken within five minutes. The statistical analysis of the obtained data was performed in the Microsoft Excel 2016 program. As a result of the research, it was found that the participation of medium-breed dogs in prolonged PSR of any type leads to changes in echocardiographic and electrocardiographic parameters, which is due to the forced adaptation of the cardiovascular system to increased stress. After participating in long-term non-normalized PSR, they showed a significant increase in the values of the final systolic size (DAC) and the final diastolic size of the CDR, an increase in heart rate (HR), shortening fraction, amplitude of the Q, R and T waves, QT/TQ ratio, PQ interval, aortic diameter, against the background of a decrease in the numerical value the electrical axis of the heart (EOS). At the same time, the increases in the thickness of the interventricular septum (IVP) and the posterior wall of the left ventricle (LVL) revealed in the second group indicate a tendency towards the development of concentric hypertrophy of the left ventricle (LV) and are an indication for regular EchoCG in animals participating in prolonged abnormal PSR, necessary for the timely detection of secondary cardiovascular disorders.

For animals, obesity is a real and growing threat, about 40—59 % of domestic dogs are overweight, and similar statistics are observed in domestic cats. These numbers have increased in recent years, and practicing veterinarians confidently assert that obesity is an increasingly serious problem among their patients. The aim of the work is to analyze the clinical manifestations, diagnostic and therapeutic measures for obese dogs and cats. The research work was carried out at the Department of Internal Non-infectious Diseases of farm animals and the veterinary clinic of the Northern Trans-Urals State Agrarian University. During the research period, 11,764 animals were admitted to the clinic, of which 4,074 (34,6 %) animals were diagnosed with obesity, including 2,319 cats and 1,755 dogs (56,9 and 43,1 % of cases, respectively). Uncontrolled feeding was found to be the main cause of overweight (73,4 % of cases). A significant risk of weight gain was noted in Labrador dogs (44,9 % of cases), in Scottish and British cats (34,6 % and 32,1 %, respectively). Of the concomitant diseases associated with obesity, pathologies of the digestive system took the leading place (42,4 %), diseases of the urinary, cardiovascular, and musculoskeletal systems were less common (20,2 %, 10,1 %, and 9,8 %, respectively). Higher therapeutic efficacy was established when using the 1st treatment regimen: dogs lost an average of 2,5—3 kg (16,2 %) after 6 months, chest circumference decreased by 13 cm, and pelvic limb index by 6 cm, body fat, respectively, by 14,9 %, body condition 5/9 points. The cats lost an average of 2 kg (23,5 %), the chest circumference decreased by 7 cm, and the pelvic limb index by 3 cm, body fat was estimated at 14,9 %, and body condition was 6/9 points. When applying the 2nd treatment regimen, dogs lost an average of 1,5 kg (6,9 %) after 6 months, the chest circumference decreased by 8 cm, and the pelvic limb index by 4,5 cm, body fat was 19,8 %, and body condition was 7/9 points. The cats lost an average of 1,6—1,8 kg (18,6 %), chest circumference decreased by 5 cm, and pelvic limb index by 3 cm, body fat was estimated at 18,9 %, body condition 7/9 points.

The review article presents a comprehensive analysis of current data on hereditary anomalies in beef cattle breeds, including hypotrichosis (HY), dilutor (DL), idiopathic epilepsy (IE), mandibulofacial dysplasia (MD), and maple syrup urine disease (MSUD). The results of genomic studies that identified key mutations (in the KRT71, PMEL, CYP26C1, BCKDHA/BCKDHB genes) and their pleiotropic effects, impacting both phenotype and productive qualities of the animals, are summarized. Particular attention is paid to the differences in the prevalence of genetic defects in cattle across various countries, which is associated with the intensity of selection, the level of inbreeding, and the effectiveness of genetic monitoring programs. Using the example of the genetic anomaly causing maple syrup urine disease (MSUD) in animals, promising therapeutic strategies are considered—from conservative metabolic control to innovative approaches using AAV vector-based gene therapy and in vitro base editing. The commonality of molecular mechanisms of hereditary diseases in humans and farm animals is emphasized, opening opportunities for translational research. Recommendations are formulated for building a genetic health management system in beef cattle breeding, based on mandatory DNA testing, inbreeding control, accounting for pleiotropic effects in selection, and the integration of advanced biotechnologies. The work is of interest to specialists in the field of veterinary genetics, breeding, and biotechnology.