Clostridiosis caused by obligate anaerobes Cl. perfringens and Cl. difficile is a serious veterinary and medical problem due to the unique resistance of their spores to external influences and the ability to form biofilms. The main difficulty in combating these pathogens is their exceptional resistance to most disinfectants, which requires the development of specialized treatment protocols. The article presents data from recent studies on the optimization of disinfection protocols in livestock complexes and medical institutions. Also, the conducted literature analysis demonstrates that a limited range of chemical agents exhibit effective sporicidal activity. The highest efficiency in vitro and under industrial conditions was demonstrated by oxidizing agents: peracetic acid (PAA, 0,5-2%) and sodium hypochlorite (1-5%). A critically important factor was the use of mandatory preliminary mechanical cleaning of surfaces, since organic contaminants (proteins, fats) reduce the efficiency of disinfectants by 30-50%. Products based on quaternary ammonium compounds (QACs) and hydrogen peroxide demonstrated insufficient efficiency against spores without a combination with thermal methods (autoclaving, steam). The resistance of clostridia is genetically determined and includes genes of antioxidant protection (sod, ahpC), sporulation (spo0A, sigK) and biofilm formation (luxS, eps). The article describes a comprehensive approach to combating clostridia – the use of effective sporicidal drugs (PAA, hypochlorites), strict adherence to a two-stage protocol (mechanical cleaning followed by chemical disinfection), and the introduction of regular microbiological monitoring to verify the quality of disinfection.

Bronchopneumonia of calves associated with the immunological immaturity of the body, causes serious damage to industrial cattle breeding. Due to the increasing antibiotic resistance of bronchopneumonia pathogens, alternative treatment methods are becoming more relevant including immunostimulants in particular allokin-alpha, which mechanism of action is to switch the mechanism of the immune response from humoral to cellular. The aim of the study was to study the effect of the immunostimulator allokin-alpha on the biochemical and immunological parameters of the blood of calves with bronchopneumonia. The research conducted in the spring period in a breeding plant in the Leningrad region on calves of the Holstein breed at three months of age and on basis of the Department of Microbiology, Virology and Immunology of the Federal State Budgetary Educational Institution of Higher Education. Total protein, albumin, globulin, urea, nitrogen, creatinine, bilirubin, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, amylase, glucose, cholesterol, calcium, phosphorus and their ratios measured in the blood of calves. Among the immunological parameters, such parameters as bactericidal activity of blood serum, myeloperoxidase, lysosomal cationic proteins, and phagocytic activity evaluated. The use of an immunostimulatory accelerates the restoration of immune system functions. Thus, the level of myeloperoxidase remains elevated by only 27,7 % relative to the control, whereas in animals without an immunostimulator this indicator is 28,4 %. Phagocytic activity significantly increased by 30,4 %, but it was approaching normal values, unlike in the first group (55,4 % higher). When allokin-alpha is used in sick animals, there is a lower protein deficiency (the percentage of globulin content is close to the norm in healthy animals, 1,1 % higher), but liver damage persists (increased transaminases). These changes indicate a gradual recovery of the general condition of the body after the disease.

Special attention should be paid to the development and implementation of innovative diagnostic methods when carrying out preventive measures, as well as operational actions in the event of outbreaks of classical swine fever (CSF) and Aujesky's disease (AD), which will allow timely detection and localization of infection foci. The purpose of this work was to design a multiplex RT-PCR test system for the diagnosis of classical swine fever and Aujesky's disease. Using bioinformatic analysis of the nucleotide sequences of the CSF virus and the pathogen of AD, the most promising sites for the indication of these pathogens were found – 139 pairs of nucleotides (bp) in size located in the region of the CSF virus genome and 135 bp in the region of the AD genome. Based on the variability of the nucleotide sequences of the selected regions, oligonucleotides were constructed that are suitable for indicating the desired viruses by RT-PCR in one tube using different fluorescence channels. Mono- and multiplex reactions were performed for each of the created combinations of oligonucleotides using a specially developed positive control, which is a genetic construct of plasmid DNA (5827 bp) containing markers for the detection of all detectable viruses and RNA/DNA samples obtained from pig biological material. Based on the results obtained, the amplification program and the optimal composition of the reaction RT-PCR mixture were determined. It was found that an individual fluorescent label corresponded to each biological pathogen. The sensitivity of the developed RTPCR test for the diagnosis of CSF and AD can reach 4 copies of DNA in the reaction mixture. When testing the multiplex RTPCR method using the strains "ShImyn" of the CSF virus and "Arsky" of the causative agent AD, the following result was obtained – an increase in the fluorescence signal along the ROX channel (Ct – 18.3) for CSF and along the R6G channel (Ct – 22.6) for AD. Thus, we have demonstrated the possibility of simultaneous PCR to identify the genomes of the desired pathogens.

Leptospirosis is a zoonotic disease that occurs predominantly in dogs in megacities, which makes the control and prevention of this disease particularly relevant for protecting the health of pets and the general population. Dogs become infected through contact with the urine of carriers or through contaminated environments where leptospires persist for long periods [1]. Serological monitoring was conducted to identify the dominant leptospire serogroup in dogs in St. Petersburg. It was found that in the period from 2022 to 2024, the predominant serogroup was Icterohaemorrhagiae (463 cases), which is confirmed by high antibody titers up to 1:1600. When analyzing antibodies to serogroups in association with the dominant serogroup, Cynopteri (52 samples) and Pomona (50 samples) were the most common. The lowest number of findings (3 samples each) was recorded for the serogroups Bataviae, Tarassovi, and Sejroe. The use of a dog leptospirosis vaccine provides protection against certain serogroups, namely Icterohaemorrhagiae, Canicola, and Grippotyphosa. However, there are no domestic vaccines in the Russian Federation that include the following serogroups: Cynopteri, Pomona, Pyrogenes, Autumnalis, Ballum, Hebdomadis, Javanica, Australis, Bataviae, Tarassovi, and Sejroe. Therefore, leptospirosis should be included in the differential diagnosis of vaccinated dogs showing clinical signs of an infectious disease. Another important task is to find fresh vaccine strains of leptospires, as the currently used strains are quite outdated, which may have led to a partial loss of their immunogenic properties. The obtained data require strengthening of preventive measures aimed at improving the epizootic situation of leptospirosis in dogs in St. Petersburg. The development and use of polyvalent vaccines containing antigens of the most common leptospire serogroups in the region, as well as the implementation of a regular serological monitoring system among the city's dog population, are of great importance.

The isolation of microorganisms in the diagnostic titer is significant evidence of the presence of bacterial pneumonia. Determination of sensitivity to antimicrobial drugs allows you to select adequate antibiotic therapy. The aim of this work was to study the microbial composition of the respiratory tract microflora in the material obtained by bronchoalveolar lavage from dogs with bronchopneumonia, and some properties of microorganisms in animals with acute bronchopneumonia. This article describes the results of a microbiological study of material from 72 dogs with signs of acute pneumonia. The animals underwent bronchoalveolar lavage (BAL) under sedation, and the selected material was sent for microbiological examination. In 65 % of sick animals, pneumonia was significantly associated with bacterial etiology. In 57 % of dogs, antibiotic resistance of microorganisms was found in BAL samples, and therefore therapy should be selected taking into account the results of microbiological examination. Antibiotic resistance was found in 47 microorganisms, and in 5 dogs, the bacteria were resistant to all the studied groups of antibiotics, and these dogs subsequently died. A combined infection (the presence of more than one microorganism in the BAL) was detected in 51.7 % of cases. Most often, antibioticresistant strains were insensitive to betalactams and tetracyclines, which is consistent with the frequency of their administration. Of the 34 species of microorganisms found in the BAL, 91.2 % were part of the normoflora or conditionally pathogenic transient microflora of the respiratory or oral apparatus, therefore, the interpretation of the microbiological study should take into account the clinical picture. Pasteurella multocida, Escherichia coli, and Streptococcus fryi were the most common.

This review summarizes and analyzes the results of scientific research on the diagnosis and treatment of feline calicivirus (FCV) infection. It has been established that continuous monitoring of the phylogenetic and molecular-genetic characteristics of FCV is essential for developing new effective primer sets for its PCR-based diagnosis. The oral cavity is identified as the preferred site for sample collection for FCV detection. Various advanced diagnostic methods have been developed, including a reverse transcription PCR (RT-PCR) method with CRISPRCas13a trans-cleavage activity, the ERA method combined with LFD (Lateral Flow Device) targeting the FCV-ORF1 region, and fluorescent isothermal analysis using Recombinase Polymerase Amplification (RPA) for rapid FCV detection. Additionally, an ultrasensitive visual detection method for FCV and FHV-1 using a single-tube dRPA-Cas12a/Cas13a assay, a triple nanoPCR method for FCV, FPV, and FHV-1 detection, and a TaqMan MGB fluorescent quantitative PCR method for simultaneous detection of FPV, FHV-1, FCV, and FIPV have been developed. Furthermore, a single PCR assay has enabled the simultaneous detection and genetic differentiation of vaccine and field strains of the virus. Effective systemic antiviral therapy for FCV is currently not developed. Consequently, supportive and symptomatic therapy, along with high-quality nursing care and feeding, play a key role in the management of infected cats. Clinical studies have shown that nitazoxanide, mizoribine, and CpG49 possess antiviral activity, while PSSNa has demonstrated good efficacy for topical application. Administration of antibodies against FHV-1 and FCV leads to a relatively rapid reduction in the severity of respiratory symptoms and overall improvement in well-being. There is evidence of a positive effect of "Roncoleukin" and "Gamapren" on FCVinfected cats and their clinical and laboratory parameters, while the administration of feline interferon combined with "Remaxol" positively influences the pro- and antioxidant balance. In vitro studies have revealed a strong inhibitory effect against FCV by mefloquine, AZD6244, sclareol, NTZ, 2CMC, NITD-008, copper chloride, and lithium chloride. Antiviral activity has also been observed for certain plant extracts, ICA, FMN, and CPAE. Survivin overexpression leads to reduced FCV infection. The secretome of feline mesenchymal stem cells does not prevent FCV entry into CRFK cells but exerts an antiviral effect on viral replication. There is also evidence regarding the potential therapeutic application of RNA interference in FCV.

The article presents data on the concurrent infection of a dairy herd with mycoplasmosis and clostridiosis, leading to persistent chronic mastitis, a purulent form with mammary gland abscesses, edema, and putrefactive decomposition of the muscles in the hind limbs. Comprehensive laboratory diagnostics (cultural studies, MALDI-TOF mass spectrometry, PCR) revealed a high prevalence of chronic (5.3%) and subclinical (53.3%) mastitis cases, as well as purulentnecrotic muscle lesions (16.6%). The primary causative agents of mastitis were M. bovigenitalium (22.2%), S. aureus (16.7–60%), and T. pyogenes, while purulent infections were predominantly caused by B. pyogenes (21.4%) and Clostridium perfringens type A. Significant antibiotic resistance was identified: 75% of E. coli isolates were resistant to fluoroquinolones and first-generation cephalosporins, 33.3% of S. aureus were resistant to second-generation cephalosporins (MecA gene), and S. agalactiae and Staphylococcus spp. showed resistance to macrolides (ErmB gene). The following first-line treatments are recommended: ceftiofur for T. pyogenes and susceptible S. aureus, gentamicin for Gramnegative infections, tilmicosin or tylosin for mycoplasmal mastitis, and fluoroquinolones for clostridial infections. Antimicrobial therapy must be based on sensitivity testing, with strict adherence to dosages and treatment duration. Prophylaxis (milking hygiene, vaccination, disinfection) and regular monitoring of resistance are of paramount importance.

The article presents the results of a study on the main hematological diseases in cats diagnosed with viral leukemia. The systematization of hematological diseases allows for further selection of replacement and pathogenetic therapy, prediction of the severity of clinical symptoms, and development of a treatment plan. The study was based on the medical records of 109 cats diagnosed with progressive viral leukemia. The progressive form of the disease was confirmed in accordance with international recommendations for PCR of the virus RNA (polymerase chain reaction with detection of the virus ribonucleic acid) or ELISA p 27 (determination of the viral specific protein p27 by immunofluorescence analysis). Hematological diseases were detected in 88% of cases (96 heads) out of 109. In the group of animals aged 1-4 years, erythropenia with thrombocytopenia was observed in 33.33% of cases (19 animals), and cytopenia with blasts was ob served in 28.07% of cases (16 animals). In the group of animals aged 5-8 years, erythropenia with thrombocytopenia was observed in 33.33% of cases (10 animals), and pancytopenia was observed in 26.67% of cases (8 animals). In the group of animals over 8 years of age, erythropenia with thrombocytopenia was detected in 55.56% of cases (5 animals), and pancytopenia in 33.33% of cases (3 animals). Thus, the most prevalent hematological disease in all age groups was a combination of erythropenia and thrombocytopenia, which was detected in 35.4% of cases (34 heads) from all examined cats with hematological diseases of 96 heads. Determining the type of cytopenia (decreased blood cells of a specific morphological line) or a combination of cytopenias is necessary for further effective therapy. To correct the combination of anemia and thrombocytopenia, the preferred treatment options are whole blood or combined hematotransfusion with red blood cell concentrate (erythrocyte mass) and platelet concentrate. This is because the therapy should focus on replenishing the two cellular lines of morphological elements.

The study was aimed at investigating the possible toxicological effect of Gentabiferon-С and Propig on the liver of white mice (n=12). The substances were administered intramuscularly once a day for 14 days at dosages of 1/10 LD50 (550 mg/kg and 641 mg/kg, respectively) and 1/50 LD50 (110 mg/kg and 128 mg/kg, respectively). The control group animals received an equal volume of sterile 0,9% NaCl solution. The mouse liver served as the material for the study. It was isolated, macroscopically assessed, then weighed, the mass coefficient was determined, and the liver was histologically examined. Macroscopic examination of the liver of mice from the experimental and control groups did not reveal any pronounced general pathological or specific destructive changes. The organ mass coefficients did not statistically differ from the control values. Histological examination revealed the presence of focal changes in animals from the experimental groups. The severity of the adverse effects was directly dependent on the dose used. Leukocyte infiltrates were present, signs of hepatocyte nuclear polymorphism and focal cytoplasmic vacuolization were noted, as well as mild hydropic edema, which, taken together, is interpreted as a manifestation of mild dystrophy. Perivascular "cuffs", small foci of fibroblast proliferation, and collagen fiber deposits were observed, indicating the onset of fibrosis. After the recovery period (10 days), positive dynamics in the restoration of liver parenchymal tissue were observed, confirmed by the results of morphometric analysis. In the group with the most severe pathology ("Gentabiferon-С", 1/10 LD₅₀), the number of inflammatory foci decreased by 81,0%, and fibrotic foci by 73,0% (p<0,05), indicating potential reversibility of the changes. Thus, the data obtained clearly demonstrate that the hepatotoxic effect is dose-dependent, is most pronounced with high doses of "Gentabiferon-С", and is largely reversible after discontinuation of the drug.

A study was conducted on the effect of enrofloxacin on the cytokinetic parameters of erythropoiesis in chickens of the Highsex Brown cross under conditions of experimental salmonellosis. Enrofloxacin, a member of the fluoroquinolones, is an antibacterial drug with pronounced bactericidal activity against gram-negative microflora, which is widely used in veterinary practice. The aim of the work is to study the effect of enrofloxacin on the cytokinetic parameters of erythropoiesis in the conditions of experimental salmonellosis caused by Salmonella Typhimurium culture. The experiment involved three groups of day-old chicks: intact control, infected control (infection with Salmonella Typhimurium) and the experimental group (infection against the background of the use of enrofloxacin at a dose of 200 mg/l with drinking water for five days). After the drug was discontinued, blood samples were taken on the second and sixth days. The number of reticulocytes was determined by the supravital staining with brilliant cresyl blue. The dynamics of the half-life of reticulocytes, the production of reticulocytes, the half-life of erythrocytes, and the production of erythrocytes were studied. Experimental salmonellosis induced significant disturbances in the kinetics of erythrocyte cell renewal, manifested by an imbalance between the processes of proliferation, differentiation, and elimination of red blood cells. The use of enrofloxacin contributed to the correction of the duration of the half-life of reticulocytes and the imbalance between the production and elimination of erythroid cells. The key result of the study in the experimental group was a significant shortening of the half-life of reticulocytes by the sixth day, which reflects the normalization of the balance between proliferation and differentiation in the erythroid lineage. The use of enrofloxacin demonstrates a protective effect on the erythron system of chickens with salmonellosis, reducing the bacterial load and correcting erythropoiesis disorders. Against the background of therapy, the balance between the production and clearance of erythrocytes is restored.

Immunotoxicity can be one of the most critical factors, with far-reaching consequences, leading to significant economic losses in the livestock industry. Therefore, the search for protective strategies against immunotoxicity caused by the simultaneous presence of several of the most dangerous mycotoxins in animal feed is urgent. The Federal Center for Toxicological, Radiation and Biological Safety has developed a multifunctional feed additive, "Galluasorb," based on halloysite from a domestic deposit. The composition of the feed additive has been carefully developed based on the pathogenesis of mycotoxicoses and includes, in addition to halloysite, methionine, milk thistle meal and β-glucans. The aim of the study was to evaluate the immunomodulatory potential of various doses of the feed additive "Galluasorb" in combined mycotoxicosis of white rats. The experiments were conducted on 60 white rats weighing 150-170 g, which were divided into five groups of twelve rats each. To reproduce mycotoxicosis and evaluate the immunomodulatory potential of the feed additive, rats of the second through fifth groups with a basic diet were given crystalline mycotoxins for 21 days: aflatoxin B1 - 2.5 mg/kg; T-2 toxin - 5 mg/kg; Zearalenone – 2.0 mg/kg of feed, rats of the third, fourth, and fifth groups additionally received 0.1, 0.25, and 0.5% of the feed additive from the diet. On days 7, 14, and 21 of the experiment, the parameters of humoral (Blymphocytes, bactericidal, and lysozyme activity of blood serum) and cellular defense of the body (the content of T-lymphocytes, leukocytes, and lymphocytes, phagocytic activity of neutrophils, including the phagocytic index, phagocytic number, and phagocytic capacity) were studied. It was shown that the feed additive "Galluasorb" has an immunomodulatory potential in combined mycotoxicosis. Doses of 0.25-0.5% of the diet were the most effective in reducing the toxic effects of T-2 toxin, zearalenone, and aflatoxin B1. However, in case of subacute mycotoxicosis, adding the feed additive "Galluasorb" at a dose of 0.25% of the diet is the most optimal from an economic point of view, since increasing the dose from 0.25% to 0.5% does not lead to increased effectiveness.

In this work, a comprehensive study of 75 samples of floral honey of various botanical origin (buckwheat, sunflower, lime, forest and meadow grasses) was carried out in order to establish a correlation between pollen composition, physico-chemical parameters and organoleptic properties. Microscopic pollen analysis was used to determine the dominant botanical origin, calculate the total content of pollen grains (OSPZ), and determine the qualitative composition of pollen in honey samples. In parallel, the main physico -chemical parameters were determined: water mass fraction, water activity (Aw), acidity, diastase number, hydroxymethylfurfural (HMP) content and electrical conductivity. The organoleptic assessment included the determination of color, aroma, taste, consistency and crystallization. As a result of the conducted research, it was established that monoflora honeys (buckwheat, sunflower, lime) have a clearly defined pollen composition with a dominant pollen content of more than 45% and a specific set of characteristics. A high WSP (>80,000 grains/ 10 g) correlates with an increased ash content and electrical conductivity, which is especially typical for honey with a predominance of pollen from plants of the Asteraceae and Fabaceae families. As a result of the evaluation of organoleptic characteristics, it was determined that each group of honey samples had a specific profile. In addition, pollen analysis is effective not only for authenticating monoflora honeys, but also for geographically linking polyflora samples. The data obtained are of practical value for the development and refinement of national and international standards for honey, to combat counterfeiting.

The aim of this study was to conduct a comprehensive analysis of the development of meat productivity in fattened young pigs over time using regression analysis, taking into account differences in the dynamics of structural changes in the ratio of muscle and fat tissue in carcasses as the animals gain live weight. This was followed by the development of selection indices for post-mortem and intramortem assessment of meat quality. During the post-mortem analysis of the dynamics of meat quality development in pigs, the numerical value of the X-coordinate at the intersection of the regression graphs of the percentage of muscle and fat tissue in carcasses relative to the animals' preslaughter weight can serve as a criterion for assessing the dynamics of meat quality in pigs and can be used as a digital index to identify the best final sire breed ensuring maximum meat quality in crossbred young pigs. The highest index value—125—was obtained when German Duroc boars were used on two-breed BKBxBM sows. A scientifically substantiated and developed selection method for identifying the best final paternal strains for industrial crossbreeding has been developed based on the expression of meat qualities in the resulting young animals. This expression is determined based on the Meat Quality Index (MQI) value, developed through a comprehensive analysis of the dynamics of these traits during in vivo assessment. Three-breed young animals, produced using German Duroc and Canadian Duroc boars, Canadian Yorkshire boars, Canadian Landrace boars, and Belarusiantype Duroc boars in the final crossbreeding stage, demonstrated the highest MQI values – 60-72.

Mycotoxins are common contaminants in animal feed. The most common mycotoxins in animal feed include zearalenone, T-2 toxin, deoxynivalenol, aflatoxins, and others. This article examined the molecular mechanism of the combined effects of T-2 toxin, aflatoxin B1, and zearalenone. The aim of this study was to investigate the effect of a mycotoxin complex on the expression level of proinflammatory cytokines (IL-1β, IL-6, IFN-γ) mRNA in the spleen of white rats and to evaluate the protective potential of the developed complex agents to reduce the induction of inflammatory processes. The experiments were conducted on 80 white rats. To reproduce mycotoxicosis, animals received crystalline mycotoxins with their basal diet for 21 days: aflatoxin B1 - 2.5 mg/kg; T-2 toxin - 5 mg/kg; zearalenone - 2.0 mg/kg of feed. Three formulations of prophylactic complexes with sorption, antioxidant, hepatoprotective and immunomodulatory properties were used as protective agents. Expression of mRNA of proinflammatory cytokines (IL-1β, IL-6, IFNɣ) was determined by quantitative real-time PCR in spleen samples. Gene expression was assessed based on the number of cDNA copies in the studied material, normalizing the indicator relative to the number of DNA copies in the same sample. It was found that associated exposure to mycotoxins causes increased expression of proinflammatory cytokine genes at the mRNA level in the spleen. The developed complexes modulated the production of proinflammatory cytokines. The prophylactic complex based on halloysite, silymarin, β-glucans, and methionine demonstrated the most pronounced immunomodulatory potential. The obtained data indicate that this prophylactic complex is promising and requires further study as a means of preventing mixed mycotoxicosis in food-producing animals.

A protein with a balanced amino acid composition is a key element in poultry feeding, necessary for intensive growth and high productivity. Deficiency of limiting amino acids (AA) in the diet inevitably leads to metabolic disorders, slower growth rates and a decrease in the productive qualities of poultry. Rapeseed proteins are well balanced in amino acid composition; in lysine content they are close to soybeans, and in methionine and cysteine, calcium and phosphorus they are significantly superior to it. The aim of this work is to evaluate the effect of replacement of some feed with rapeseed in the amount of 25-75% of the broiler chicken diet on the amino acid profile of the body. The experiment involved 4 groups of fistula broiler chickens of the Smena 9 cross (N = 20, n = 5): 1 (k) - basic diet (BD) + crude fat (CF) 5%; 2 (o) - BD + 25% rapeseed (RS) (9.5% CF); 3(o) – OR with 50% RS (19% CF); 4(o) – OR with 75% RS (28.5% CF). Amino acid analysis of blood serum was performed by ion-exchange chromatography with post-column derivatization with ninhydrin. The introduction of rapeseed into the broiler diet contributed to a reliable (p≤0.05) increase in the content of Val, Gly, Ser in the blood of chickens from the experimental groups, as well as a marked increase in the level of Arg, Ala, Cys, Met and Lys. The 2nd group is characterized by the highest content of a number of functional amino acids: Asp, Thr, Ser, Glu, Gly, Ala, Val and Leu, however, the ratio of the sum of essential AAs to replaceable AAs was the best in the 4th group, which is due to the high content of Met, Ile, His, Lys and Arg along with a lower concentration of a number of replaceable AAs. Thus, replacing the grain portion of the broiler chicken diet with rapeseed in an amount of 25-75% has a pronounced effect on the overall amino acid profile of the blood.

The sable of the black Pushkin breed is an outstanding achievement of breeders in the field of animal husbandry. Its biological features, formed as a result of targeted breeding, ensure the production of skins with unique qualities: deep black color, high density, silkiness and shine. The purpose of the study was to study the histological features of the kidneys of males and females of the black Pushkin breed in the age aspect, as well as to determine their morphometric parameters, and analyze the data obtained. Kidney samples were subjected to histological examination. The material was fixed in a 10% solution of neutral formalin for 24 hours, after which it was poured into paraffin according to the generally accepted method. Then sections 5-7 microns thick were made, which were stained. The analysis of the presented morphometric data on the age-related features of the kidneys in the studied individuals makes it possible to identify clear patterns of growth of all the studied structures with age, as well as minor sex differences. According to all the parameters studied, there is a statistically significant increase in values in animals of the second age group compared with the first. This applies both to the thickness of the general layers of the organ (capsule, cortical and cerebral layer) and microscopic structures (tubule epithelium, vascular glomerulus, renal corpuscle, collecting tubules). This growth is a natural consequence of the general somatic development and maturation of the body. An increase in the thickness of parenchymal layers (cortical and cerebral) is associated with the ongoing process of growth and differentiation of nephrons in the postnatal period, an increase in the size of renal tubules and glomeruli. An increase in the diameter of the vascular glomerulus and the renal corpuscle indicates the development of a filtration apparatus, which corresponds to an increase in the level of metabolism and the need for more intensive blood purification in adults. The thickening of the kidney capsule and the walls of the tubules (single-layered cubic epithelium) also reflects the structural strengthening of the organ during ontogenesis. Also, in both age groups, the absolute values of the morphometric parameters of these structures in males consistently exceed the parameters of females. This difference can be traced both in 15-20-month-old animals and at the age of 36-40 months.

One of the key physiological factors determining the success of reproduction is the oxidative status of the body, since during gestation, farrowing and location, the level of metabolic stress in sows increases, accompanied by increased formation of free radicals. The aim of the study was to comprehensively evaluate the effectiveness of lithium ascorbate in modulating the antioxidant system of sows during gestation. For this purpose, an experiment was conducted on clinically healthy sows, which were divided into two groups: control and experimental. The animals in the experimental group were given lithium ascorbate orally at a dose of 10 mg/kg body weight per day throughout the entire reproductive cycle, including the service period, gestation, and lactation. The control group did not receive any supplement. To assess the antioxidant status, blood samples were collected from the sows on days 30 and 110 of gestation to measure the concentrations of glutathione (GSH and GSSG), calculate the thioldisulfide ratio (GSH/GSSG), and determine the level of malondialdehyde (MDA). It has been established that the use of lithium ascorbate causes statistically significant changes in indicators of oxidativeantioxidant homeostasis in pregnant sows. In the experimental group, there was an increase in glutathione (GSH) levels and a decrease in glutathione disulfide (GSSG) content, leading to an improvement in the GSH/GSSG ratio compared to the control group. Additionally, a reduction in malondialdehyde (MDA) concentration was observed. The positive effects were more pronounced on day 110 of gestation, which corresponds to the period of maximum physiological stress. The results suggest that lithium ascorbate has antioxidant activity in sows during pregnancy, possibly through activation of the glutathione system and inhibition of lipid peroxidation. These findings support the potential use of lithium ascorbate in feeding schemes to prevent oxidative stress and support the reproductive health of sows in conditions of increased physiological and environmental stress.

The study of the anatomical features of the oral apparatus of fur-bearing animals, as one of the promising branches of agriculture, contributes to improving the conditions of their captivity and improving the quality of furs. 10 preparations of salivary glands of physiologically mature black Pushkin sables were studied. The aim of the work is to study the features of the histological structure of the salivary glands of the black Pushkin sable and to determine the morphometric parameters of these organs. Samples of the mandibular, parotid, and sublingual salivary glands were subjected to histological examination. The material was fixed in a 10% solution of neutral formalin for 24 hours, after which it was poured into paraffin according to the generally accepted method. Then sections 5-7 microns thick were made, which were stained with hematoxylin and eosin, picrofuxin according to Van Gieson and trichrome according to Masson in order to identify collagen fibers. Some of the sections were stained with Alcian blue (pH 2.5), followed by additional staining with Mayer's hematoxylin. Histological preparations were analyzed using a Carl Zeiss AxioSkop 2 plus light-optical microscope (Germany) at magnifications of 40, 100, 200 and 400. Microphotography was performed using an AxioCam ERc5s digital camera and AxioVision Rel software. 4.8 (Germany). Morphometric measurements were performed manually using the AxioVision Rel software. 4.8. All anatomical terms correspond to the "International Veterinary Anatomical Nomenclature", fifth edition, translation and Russian terminology by Professor Zelenevsky N. V. (2013). As a result of the study, the features of the histological structure of the salivary glands of sables were revealed, as well as their morphometric parameters were determined.

The purpose of this work is to study the hematological parameters of ducklings' blood in conditions of experimental Staphylococcosis, using the chemotherapeutic drug ciprofloxacin, which has a wide spectrum of action. Ciprofloxacin has a more active effect on aerobic gram-negative bacteria, as well as on staphylococci. To conduct the study, three groups of ducklings were formed (I – control, II and III – experimental). Experimental infection of ducklings of groups II and III with Staphylococcus aureus culture was carried out. The day before and for four days after infection, ducklings of group III received ciprofloxacin at a dose of 200 mg/l together with water. Blood sampling from all experimental birds was carried out on the first, third, sixth, ninth and thirteenth days after infection. The parameters of the erythron system, as well as the number of leukocytes and the leukocyte formula, were studied, and the leukocyte indices were calculated. The research results indicate a positive effect of ciprofloxacin on ducklings in experimental staphylococcal infection. The recorded changes in red blood counts were reversible, short-term, and did not adversely affect the ducklings' physiological condition. As a result of the analysis of the data obtained, statistically significant changes in white blood parameters in groups II and III were noted relative to the control group. Experimental infection caused shortterm leukocytosis, which manifested itself in all experimental groups. The presence of an inflammatory reaction was found, characterized by a significant increase in the absolute number of pseudoeosinophils and monocytes in groups II and III in comparison with the control. Nevertheless, the hematological parameters of blood in group III were relatively closer to those of the control group. Dynamic shifts in the indices of nonspecific reactivity and endogenous intoxication are most informative and prolonged in experimentally infected ducklings that did not receive ciprofloxacin.

The aim was to identify clinical and biological situations in which BRD4 inhibition provides anti-tumor and/or anti-fibrotic benefit, and when it may interfere with physiological tissue regeneration. A targeted search of PubMed, Scopus, and Web of Science identified original research and clinical trials. We included studies on BRD4 function at super-enhancers (genomic regions that strongly amplify gene transcription), data on regeneration and fibrosis, and reports on BET inhibitors and BRD4 degraders. BRD4 is a key node sustaining the activity of genes that determine cellular “behavior”; consequently, tumors dependent on superenhancers are vulnerable to BRD4-directed interventions. The most convincing clinical effect has been shown in myelofibrosis: adding a BET inhibitor to ruxolitinib outperforms standard monotherapy on major endpoints. In prostate cancer, combinations with BET inhibitors show a reproducible signal of efficacy in selected subgroups, whereas BET monotherapy in solid tumors is often only modestly active. At the same time, prolonged or “total” BRD4 blockade can impair functions of tissues that require BRD4 for homeostasis (e.g., the heart and actively forming bone), while BET inhibition reduces myofibroblast activity and dermal fibrosis in preclinical models. Modality matters: panBET/BD1-oriented regimens are more appropriate in oncology; BD2-selective strategies fit inflammatory/fibrotic contexts; PROTAC-based approaches are promising but require targeted delivery and careful safety monitoring. BRD4 inhibition is justified where pathological super-enhancer–dependent transcription predominates and is more effective as part of well-designed combination regimens with biomarker-guided patient selection. Prolonged systemic exposure should be avoided during active tissue repair, favoring short, local, and/or domainselective regimens.

The article presents the chemical composition of native dental calculus in dogs. The study was carried out on the basis 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 Quality Control of Medicines of the Saratov State Medical University named after V. I. Razumovsky of the Ministry of Health of the Russian Federation 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. The object of the study was dogs (n=300). The material for the study was a native dental stone, which was obtained during the rehabilitation of the maxillary system in dogs at the Tsentralnaya na Moskovskaya veterinary clinic (Saratov). A laboratory method was used, which includes qualitative and quantitative chemical analysis, which established a diverse number of mineral accumulative formations. Thus, the maximum values were reached by calcium - 384.67±6.51 mg/g and carbon dioxide - 154.84±2.56 mg/g, and the minimum values were phosphorus – 1.15±0.02 mg/g and fluoride ions - 0.23±0.04 mg/g. In our opinion, the mineral composition of the dental calculus can be influenced by many factors, such as the characteristics of feeding and maintenance, the time of residence of this formation on the surface of the teeth, the degree of its mineralization, the age of the animal, the breed and morphological type of the head. The data presented by us can serve as extrapolation results, thanks to which it is possible to create a more complete picture of the chemical composition of dental calculus in dogs, which is important to take into account when rehabilitating the oral cavity.

The article presents the results of a pathoanatomical autopsy of a calf of a Pacific bottlenose dolphin (Tursiops aduncus) and the results of histological and histochemical examination of selected organ samples. We have been diagnosed with pulmonary nocardiosis. Nocardiosis is an infectious disease caused by various aerobic soil saprophytes, gram-positive rods of the genus Nocardia. The disease can manifest itself as an acute, subacute, or chronic infection, often in a cutaneous, pulmonary, or disseminated form. Nocardia spp. They cause pyogranulomatous lesions of various organs in mammals, most often the lungs. Macroscopically, nodular, abscessing, erosive, ulcerative, fungous (fungal) and diffuse forms of actinomycosis are distinguished. Cattle are susceptible to actinomycosis and nocardiosis, less often pigs, sheep, goats and horses, and marine mammals. Infection occurs when dust containing bacteria is inhaled, or when bacteria enter the body directly through cuts or scratches, when contaminated soil or water enters them. Studies of seawater and the seabed have revealed the presence of actinobacteria of different genera and species. In both pinnipeds and cetaceans, young animals are more likely to become ill than adults. During histological examination with hematoxylin and eosin, as well as by the method of acid-resistant staining, it is impossible to reliably identify bacteria of the Actinobacteria class. However, modified acid-resistant staining and the Grokott method using silver methenamine not only reveals the characteristic features of actinobacteria, but also makes it possible to differentiate Nocardia from Actinomycetes. There is only one report in the literature about pulmonary nocardiosis in the Pacific bottlenose dolphin (Tursiops aduncus), and therefore we believe that our clinical case deserves attention.

In the industrial production of poultry products, agricultural poultry must meet certain requirements – the level of productivity and technological properties. Commercial poultry farming currently has highly productive chicken crosses in its arsenal, from which eggs with white or brown shells are obtained. The variety in eggshell coloring is due to the demand in the consumer market and the productive qualities of the crosses themselves. Many people believe that one of the advantages of brown-shelled eggs is their thick and durable shells. However, the proportion of all damaged eggs in poultry farms indicates a high degree of damage to their shells, both white and brown. In this regard, the morpho-biophysical qualities of the egg shells of Hisex Brown cross chickens were studied depending on the intensity (weak, medium and strong) pigmentation of their shells using special techniques and devices. All the hens of the Hisex Brown cross were in the same feeding and maintenance conditions. Studies have shown that eggs with light brown and brown shells have the best shells. The shells of these eggs were thicker by more than 2-2.5% and heavier by 5.1% and 1.15% compared to eggs with weak and strong pigmentation, respectively. This determined a decrease in the elastic deformation index by more than 4% lower, and the shell strength was higher by 12.83% (P≤0.1) and 1.57% than in the groups with weak and strong pigmentation.

Probiotics offer advantages over other adaptogens in equestrian sports, as they are administered orally with feed without requiring skin penetration. They also maintain intestinal microflora balance, thereby preventing colic in horses. Furthermore, probiotic use eliminates the risk of using prohibited drugs in sports, unlike herbal dietary supplements. The search for ways to enhance horses' adaptability to physical exercise remains relevant today. The aim of our study was to evaluate the effect of a probiotic on the leukogram of sport horses. Our study examines the use of the probiotic "BonacaAPC" as an adaptogen for Arabian horses participating in endurance racing. The leukogram was calculated by counting the leukocyte forms in blood smears stained with the May-Grünwald method. Leukocyte counting was performed in a counting chamber with a Goryaev grid. In the experimental group, we observed a smaller increase in the relative number of segmented neutrophils in response to physical exercise, as well as a higher relative and absolute number of lymphocytes. Neutrophils and lymphocytes are the most reactive cells, responding most quickly to changes occurring in the body during physical exercise. Based on our research, the probiotic "Bonaca-APK" increased the adaptive capacity of horses, resulting in a less stressful cellular response. Therefore, it can be recommended for use in sport horses as an adaptogen to physical exercise, while also helping to maintain intestinal microflora and reducing the risk of colic, which is also important in equestrian sports.

Ophthalmotonometry is a non-invasive method for recording intraocular pressure (IOP) and is widely used in preclinical studies for the early detection of toxic effects and a comprehensive assessment of the pharmacological activity of drugs. This article presents the reference intervals for intraocular pressure in cynomolgus macaques, dwarf pigs, rats, and Pannon and Soviet Chinchilla rabbits. The reference intervals were obtained from healthy cynomolgus macaques (n=50), Wistar rats (n=80), dwarf pigs (n=36), Soviet Chinchilla (n=80), and White Pannon (n=62) rabbits at JSC NPO DOM PHARMATII between May 2024 and July 2025. Measurements were performed in sexually mature and immature males and females (non-pregnant and nulliparous, ignoring the estrous cycle phase). Measurements were performed using a TonoVet veterinary tonometer on male and female laboratory animals of various ages. The smallest variation in individual IOP values was observed in Soviet Chinchilla and White Pannon rabbits, not exceeding 10.5%. The vast majority of studies published in experimental ophthalmology use New Zealand albino rabbits (a New Zealand breed). However, excluding animals with melanin-containing eyes significantly reduces the translational value of the research, as most humans have pigmented eyes. These results can be used in preclinical drug toxicity studies, in assessing the pharmacological activity of antihypertensive drugs in in vivo glaucoma models, and in diagnosing diseases in exotic animals.

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-day -old 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 angioosteotopic 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 watersoluble substances into the venous blood. The glandular stomach has an ovalelongated 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.

This study presents the results of a postmortem examination of three 4-day-old piglet carcasses that died following the intramuscular administration of the ironcontaining drug Erytrofer 200 at a preventive dose of 1 ml. The aim of the research is to draw the attention of veterinary specialists to the problem of postmortem diagnosis of drug-induced anaphylactic shock caused by the parenteral administration of iron preparations. The materials were based on protocols of forensic veterinary examinations of three cases of drug-induced anaphylactic shock with lethal outcomes. During the autopsy, the following pathological diagnoses were established: staining of surrounding tissues, edema and focal necrosis of muscles at the injection site; staining of regional lymph nodes; myocardial dystrophy ("paralytic heart"); acute congestive hyperemia of the membranes and cerebral edema; acute congestive hyperemia and pulmonary edema; edema of the subcutaneous tissue, lymph nodes, and mesentery of the large intestine; acute congestive hyperemia of the liver and spleen; edema and protein degeneration of the kidneys; petechial hemorrhages on the serous membrane of the colon and the renal cortex; anemia of the mucous membranes and muscle tissue. It was determined that the death of the animals occurred due to anaphylactic shock induced by the administration of the iron-containing drug. The immediate cause of death was cardiac paralysis resulting from acute heart failure and hypoxic conditions, exacerbated by cerebral and pulmonary edema. The injection site in the neck region contributed to the development of a hyperergic inflammatory reaction with edema of the surrounding tissues.
The research materials include descriptions of the gross pathology of the external integuments and internal organs. The paper presents photographs of the piglets' organs with pathological changes characteristic of drug-induced anaphylactic shock provoked by the use of Erytrofer 200.

The article presents the results of an assessment of the quantitative and qualitative characteristics of the blood of Even domestic reindeer depending on the season. Biological material was collected dynamically in accordance with the provisions of the Declaration of Helsinki from Even animals of various ages. The influence of the pronounced seasonality of the feeding behavior of domestic reindeer in the Sakha Republic (Yakutia) on the morphological and biochemical parameters of the blood of various age groups of experimental animals, including lactating females, was established. Thus, the parameters such as the red blood cell count (RBC) and hemoglobin content (Hb) are most determined by age and season, with the lowest values recorded in newborn calves, reaching peak values in the autumn period at 9 months of age. The hematocrit of the newborn calf was also relatively low (35.4%), showing a significant increase in the summer and reaching a maximum (48.9%) and adult levels in the fall, while positively correlating with Hb (r = 0.93) and with RBC (r = 0.77). The white blood cell (WBC) count ranged from 6.1 to 10.1 x 10⁹/L and showed a significant increase during the first weeks of life (P < 0.01), reaching maximum and adult levels in the fall. The serum iron concentration in the newborn calf was quite low (26.4 μmol/L), but almost doubled during the first summer, with values being slightly higher in calves than in females in summer and fall. The obtained variations in blood composition, in our opinion, can be used as predictors of animal survival and calving success, as well as for determining reference values for the blood of Even reindeer.

Inflammation is a typical pathological process that plays an important role in protecting the body, but the course of the process can vary significantly depending on the type of tissue and individual characteristics of the animal, including the blood profile, which is key in determining the nature and intensity of the inflammatory process, depending on the composition of circulating immune system cells, the level of proinflammatory cytokines and complement activity, which in turn, it affects the course and speed of the inflammatory process, as well as the effectiveness of protective mechanisms. Currently, cellular integrative markers of systemic immune inflammation, such as neutrophil-lymphocytic, plateletlymphocytic, and systemic immune inflammation index, are becoming increasingly common in clinical trials. Coefficients are widely used in humane medicine as an independent predictor of the systemic inflammatory response, determining the severity of diseases. In this regard, it seems relevant to analyze the diagnostic significance of indices in veterinary medicine when assessing the systemic response to inflammation of various types of tissues. The purpose of the study – to conduct a comparative assessment of leukocyte indices in inflammation of glandular and connective tissue in animals with a lymphocytic blood profile. The object of research is cattle, divided into groups depending on the type of tissue with an inflammatory process: 1st - clinically healthy; 2d - with inflammation of glandular tissue; 3d - with inflammation of connective tissue. As a result of the comparative analysis, we found that the systemic inflammatory response of glandular tissue is more pronounced in animals with a lymphocytic blood profile compared to connective tissue, and the development of complications in the form of a cytokine cascade is most likely with inflammation of this type of tissue. The calculation of hematological indices in animals is informative for assessing the pathophysiological aspects of inflammation, due to its ease of calculation, it can also be recommended for use in clinical practice in order to assess the degree of the inflammatory process and determine the prognosis of diseases.

The immune system of fish, as the first vertebrates to possess all the main components of adaptive immunity, is of considerable interest for comparative immunology. In fish, as in other vertebrates, the immune system provides protection against a variety of pathogens; however, due to the peculiarities of their habitat, they have distinctive immune response properties. The organization of the immune system of fish is an important stage in the evolution of higher vertebrates, thus reflecting the idea of the formation of immunity in higher vertebrates. The review systematizes current data on the evolution, structure, and functioning of immunity in jawless and jawless fish. The aim of the work was to analyze and discuss existing knowledge about the role of various organs and individual genes involved in the defense mechanism of jawless and jawless fish, based on which it is possible to form an idea of evolutionary changes in the immune system of fish. Fish immunity is a complex system that depends on many factors, such as environmental conditions and genetics. Knowledge of the mechanisms of fish immune defense is fundamental to understanding the evolution of the vertebrate immune system and is the basis for developing effective strategies in aquaculture, for example, to create vaccines and immune stimulants. A comparative analysis of modern literature data was carried out, in which studies reflecting the characteristics of the immune response in fish were carefully selected. The results of the generalization are necessary for further study of the resistance of aquaculture facilities to various pathogens in order to grow commercial fish safe for humans.

Histomorphometric examination of the placenta of mares in the final stages of gestation revealed statistically significant differences in morphometric parameters during the physiological and pathological course of pregnancy. The area of the chorioallantois (cm2), the thickness of the chorion and allantoamnion (mm), the density of villi per unit area (villi/cm2) and per unit surface of the chorion, as well as the diameter and number of vessels in the allantoamnion per area of 100 cm2 were quantified. The analysis showed that placental insufficiency, manifested in the form of premature birth, placentitis and retention of the afterbirth, is associated with the disorganization of cellular structures, characterized by their sparse arrangement in the form of small, distant clusters. In contrast, the formation of denser and more coherent cell clusters is observed in mares with physiological pregnancy. Histomorphometry of the cellular structures of the fetal part of the placenta, in particular, the topological metrics of the network, acts as the main discriminating factor that makes it possible to quantify the specific features of the placenta of mares in conditions of pathological conditions. The distribution of chorioallantois villi over the entire surface of the placenta and the absence of dense contacts with the glandular epithelium of the uterus form microcotyledons, which determines the classification of the placenta of mares as diffuse microcotyledonous epitheliochoric. There is marked vascularization of all components of the placenta, including the amniotic membrane, stem and terminal villi of the chorioallantois. The stromal part of the placenta, represented by the amniotic membrane and chorioallantois villi, consists mainly of collagen fibers. The presence of long stem villi in certain areas of the placenta (distal part, middle of the contralateral horn, dividing line of the horns, middle of the main horn) correlates with their spatial location in the uterus, providing optimal contact with the uterine glands for effective gas exchange and nutritional support of the fetus.

Maintaining the genetic stability of farm animals under adverse environmental conditions is often associated with the state of the antioxidant system and is a pressing issue in veterinary medicine. Our data demonstrate that pharmaceutical substances containing hydrophilic bovine spleen cryofraction (HBSC), lipophilic bovine spleen cryofraction (LBSC), and a mixture of lipophilic bovine spleen and placenta cryofraction (LBSPC) exerted an antimutagenic effect on the animals; however, the mechanism of this effect is far from fully understood. Therefore, the aim of this study was to investigate the effects of HBSC, LBSC, and LBSPC on certain parameters of lipid peroxidation (LPO) and antioxidant defense (AOD) in the blood of rats under conditions of oxidative stress induced by cyclophosphamide (CP). The effects of separate intramuscular administration of pharmaceutical substances at a dose of 0.5 ml/kg and their combined administration with an intraperitoneal injection of CP at a dose of 40 mg/kg in white laboratory male rats were studied. The effects of three doses of HBSC, LBSC, and LBSPC administered 24 hours apart before the CP injection were also studied. A single administration of HBSC, LBSC, and LBSPC did not induce statistically significant changes in lipid peroxidation and antioxidant protection in the blood of rats. A course of HBSC, LBSC, and LBSPC administered to rats reduced oxidative stress induced by CP due to its effect on antioxidant enzymes. This was reflected in a significant (more than 2-fold) increase in catalase activity, as well as glutathione peroxidase activity (by 71-79%), and a decrease in the levels of intracellular reactive oxygen species, diene conjugates, and ketodienes relative to animals in the positive control group. Thus, HBSC, LBSC, and LBSPC possessed an antioxidant effect, manifested by modulating the activity of the enzymatic component of the antioxidant system.

Homozygous regions in the genome serve as markers of areas under selective pressure. These regions likely harbor genes responsible for key production traits targeted in breeding programs. For this study, we performed whole-genome genotyping at 30×coverage on DNA extracted from blood samples of Chinese Silkie chickens (n=20) maintained at the Center for Genetic Collections of Rare and Endangered Chicken Breeds (Pushkin, St. Petersburg, Russia). Our aim was to identify runs of homozygosity (ROH) in this population and pinpoint genes within them that relate to adaptive traits and immune resilience. After quality filtering, we analyzed 10,593,367 SNPs. We detected ROH on chromosomes 1, 3, 4, 7, and 9, encompassing nine regions that collectively contain 40 genes. Of these, we annotated 25 genes; here, we focus on those that directly or indirectly influence adaptive capacity and immune responses in chickens: HAAO gene on chromosome 3, and ATP5G3, ATF2, WIPF1, SCRN3, CIR1, and OLA1 genes on chromosome 7. Functional annotation links these genes to adaptive and physiological processes in chickens. The HAAO gene contributes to multiple roles, including the heat stress response. Meanwhile, ATF2, ATP5G3, OLA1, WIPF1, SCRN3, and CIR1 form a cluster associated with stress reactivity, immune function, mitochondrial activity, and cellular homeostasis. Together, they modulate energy metabolism, oxidative stress, inflammatory signaling, tissue repair, and intercellular communication. This gene set underscores the importance of metabolic robustness, immune defense, and stress adaptation to the distinctive phenotype of the Chinese Silkie population. We posit that homozygosity at these loci enhances the breed's hardiness and adaptability across diverse rearing conditions.

In the evaluation of Holstein bulls, the "Heifer Life Expectancy" (HLIV) trait is a health indicator. Selecting for this trait can reduce animal mortality and lower herd replacement costs. The predicted HLIV transmission capacity is positively correlated with milk production, as well as with the traits "Productive Life Expectancy," "Easy Calving," and "Approaching First Calving." However, the level of genetic potential realization for these traits varies significantly among the daughters of different bulls. The purpose of the research is to conduct a comparative assessment of the preservation, growth, and development, as well as the milk production and the implementation of the predicted HLIV transmission capacity in the offspring of Holstein bulls with equal HLIV values, which are kept under the same conditions of housing, feeding, and operation. The research was conducted at a breeding farm in the Stavropol Territory on Holstein animals from birth to the end of their first lactation. According to the primary zootechnical and veterinary reports, the live weight, survival rate of the experimental animals from birth to 18 months, milk yield, and percentage of fat and protein in milk during the first 305 days of lactation were studied. It was found that, despite the similar evaluation of the bulls based on HLIV, their offspring had significant differences in the studied parameters. It was found that, with the same evaluation of bulls-producers by the HLIV trait, their offspring had significant differences in the studied indicators. The heifers of the I experimental group exceeded the heifers of the II experimental group in live weight at all periods of cultivation. The greatest difference in this indicator was at the age of 18 months – 39.0 kg. The survival rate in the first experimental group was 94.7%, compared to 88.5% in the second experimental group, with milk yields of 7869.9 and 6683.0 kg, respectively.

Animal genome editing, particularly in chickens, is a rapidly developing field of biotechnology with significant implications for agriculture, fundamental science, and medical research. The domestic chicken is a model animal in immunology, embryology, and infectious diseases. The advent of modern gene editing technologies, including the CRISPR/Cas9 system, TALENs, and homologous recombination, has opened new possibilities for precise modification of the chicken genome. Chicken genome editing technologies are demonstrating rapid progress between 2019 and 2025, spanning both breeding and conservation applications, opening new prospects in several areas simultaneously. From a practical perspective, breeders have gained the opportunity to create poultry with increased resistance to common infections. Equally important is the application of genome editing methods to address conservation issues. Cryopreservation of primordial germ cells from rare and endangered chicken breeds allows for the preservation of a full set of genetic information—including mitochondrial DNA and the W chromosome, unique to females—that is inaccessible when freezing sperm alone. Hungarian colleagues have created a functioning cryobank of six national breeds with engraftment rates of up to 100%. These technologies have successfully restored several endangered chicken breeds in China and Japan. This combination of applied and conservation aspects makes avian genome editing technologies a promising area of modern biotechnology. This paper presents a comprehensive analysis of the current state of avian genome editing technologies, examining the main approaches to genetic modification, including work with primordial germ cells, the use of viral vectors, and direct embryo editing. Particular attention is given to advances in the creation of pathogenresistant chicken lines, the development of gene knockout models for studying their functions, and the development of biotechnological systems to produce therapeutic proteins. The prospects for using genetically modified chickens in biomedical research and the production of biopharmaceuticals are analysed.

Study examines impact of cryopreservation cycle on sperm viability and individual functional activity in rooster ejaculates. Analysis revealed that proportion of live cells in fresh semen was at level 77.16±1.93%, while the mitochondrial membrane potential (ΔΨm) remained high, was at level 81.07±1.52% with a low correlation coefficient (5.93%), indicating good cell viability and energetic activity. After cryopreservation process was observed a significant decreasing in percentage of live cells (to 52.12±3.99%), an increasing in proportion of necrotic cells (by 12.37%), and a decrease in high ΔΨm by almost 33.41%, and an increase in the proportion of cells with signs of necrosis (by 12.37%) are observed. The relationship between mitochondrial activity and viability indicates the important role of mitochondrial membrane potential as a prognostic marker of frozen/thawed semen quality. High individual variability in these parameters after a freeze/thaw cycle indicates heterogeneity in cryopreservation within the tharskoselskaya rooster population, which is important to consider when developing effective cryopreservation methods. The results highlight the usefulness of using viability and functional activity indicators (mitochondrial membrane potential) in assessing the quality and predicting the effectiveness of rooster sperm cryopreservation.

A study was conducted to investigate the impact of genomic inbreeding (FROH) and the level of homozygosity (Ca) on milk productivity and reproduction. To assess the impact of FROH, data on SNP markers from 196 sires were used; FROH was then assigned to daughters (n=64,027). FROH was calculated as the ratio of the sum of all lengths of homozygosity patterns (ROH) in million nucleotide pairs (mb) in the sire genome to the total genome size in mb for 29 bovine autosomes overlapping SNPs, expressed as a percentage. To calculate the impact of inbreeding (Fx), 196 bulls and 64,027 daughters were used, and Ca for STR markers from 228 bulls and 80,849 daughters was used. To assess the influence of the cows' own Fx, a dataset of 39,276 heads was used. Fx was calculated using the WrightKislovsky formula, the Ca level as the ratio of the number of homozygous loci to the total number of analyzed loci. The optimal Fx level for obtaining high milk productivity indicators is the range of 0-3.125%. A high level of inbreeding (6.25-12.5%) negatively affects milk fat content. Thus, a reliable relationship was established between the level of inbreeding for STR markers and the productive qualities of daughters. From the point of view of milk productivity, the minimum level of inbreeding is optimal. All indicators demonstrate statistical significance (p=0.00). A systemic effect of genomic inbreeding on all the studied traits is observed, and the protein content indicator turned out to be the most sensitive. Reproductive qualities demonstrate a moderate dependence on the factor. As practical suggestions, it is possible to recommend using moderate classical inbreeding within 0-3.125%; control the level of genomic inbreeding in the range of 4.2-7.5% and take into account the level of homozygosity for FROH and STR markers when selecting pairs, as well as conduct reg ular monitoring of productivity and reproduction indicators.

The aim of the experiment was to study the effectiveness of vaccination of deep-wall cows with anemia against viral infection against the background of the use of biogenic stimulants and cytokines, their effect on the immune status. The study involved cows (n=25) of red-mottled breed in the third trimester of pregnancy, healthy and diagnosed with anemia. Animals with anemia were treated with a biogenic stimulator based on hydrophilic cryofraction of the spleen (BoHCFS) and its combination with cytokines (BoGM-CSF, BoIFN-α, BoIFN-λ). The drugs were administered intramuscularly three times with an interval of 48 hours. The introduction of the above –mentioned pharmacological agents was carried out 1 week before the re-introduction of the «HIPRABOVIS 4» vaccine, which was used 60 and 30 days before the planned calving date of the cows. It has been established that in animals with anemia, the level of neutrophils capable of phagocytosis remains, but their absorption and digesting ability decreases. They also have a decrease in the activity of the complement system and the number of B-lymphocytes. Later, during pregnancy, the noted negative changes in the immune system not only persist, but also intensify. The use the BoHCFS-based drug enhanced the spontaneous and stimulated NBT test by 41.2 and 13.0%, increased the phagocytic number and index by 11.1 and 10.4%, and the number of T and B lymphocytes by 43 and 70.2%, respectively. All this was reflected in the level of total immunoglobulines and bactericidal activity of blood serum, which increased by 15.4 and 5.1% respectively. As a result, most of the indicators reached the values of healthy animals, but the level of phagocytic activity of neutrophils and lysozyme activity of blood serum was still lower. The combination of BoHCFS with BoGM-CSF, BoIFN-α and BoIFN-λ made it possible to completely neutralize the system and increase the effectiveness of vaccination of deep-bed cows.

The aim of this study was to assess the population-genetic structure and parameters of genetic biodiversity at the polymorphic locus g.4491A>G (A375G) of the GHRL gene in cattle of the Tatarstan type of the Kholmogor breed. Ghrelin, encoded by the GHRL gene, plays a key role in regulating appetite, energy metabolism, growth, and dairy productivity, making it a promising marker for breeding. Blood samples from 91 cows served as the material for DNA testing. Genotyping was performed using PCRRFLP with the BstKT I restriction endonuclease. As a result, three genotypes were identified: AA (9.9%), GA (52.7%), and GG (37.4%). The frequency of allele A was 0.363, and that of allele G was 0.637. Population-genetic analysis showed that the studied population is in a state of HardyWeinberg equilibrium, with a predominance of heterozygous genotypes observed, and the polymorphism information content (PIC) characterizes the locus as moderately polymorphic and informative for breeding programs. A comparative analysis with literature data revealed significant interbreed and geographical variability in the frequencies of the GHRL gene. The obtained results emphasize the importance of considering the genetic specificity of local breeds and confirm the potential of using GHRL gene polymorphism as a molecular-genetic marker to enhance the efficiency of cattle breeding. The study was carried out within the framework of the state assignment, registration number 125031003428-9.

The article presents the results of monitoring the prevalence of the HH6 fertility haplotypes, a lethal recessive genetic defect relevant to modern Holstein cattle breeding. The study was conducted on a sample of 194 animals (94 bulls and 100 cows) selected from three leading breeding enterprises in the Russian Federation. Genotyping was performed using a combination of PCRRFLP and real-time PCR methods aimed at detecting a point mutation (g.29020700 A>G) in the SDE2gene (telomere maintenance homolog). The PCR-RFLP method involved the amplification of a 524 bp gene fragment, followed by analysis of restriction-patterns. To validate the results, real-time PCR was performed using the commercial reagent kit «HH6-RT-100» (VetGenomika LLC, Novosibirsk). The analysis identified one carrier bull of the HH6 mutation among the 94 bulls tested, corresponding to a carrier frequency of 1.1%. No carrier cows were detected. The obtained data underscore the importance of continued systematic screening to control the spread of the HH6 haplotype. The developed PCR-RFLP methodology proved to be reliable and is recommended for implementation in the practice of breeding farms and laboratories engaged in genomic selection. The implementation of DNA testing will prevent inbred matings and minimize economic losses associated with embryonic mortality, thereby contributing to the improvement of breeding and selection programs in dairy cattle farming.

Reindeer herding remains a cornerstone of traditional livelihood for indigenous peoples of the Republic of Sakha (Yakutia), where harsh climatic conditions profoundly shape the reproductive cycle of domestic reindeer (Rangifer tarandus). This study examines the seasonality of calving and the morphofunctional characteristics of the parturition process in female reindeer (vaizhenki) across diverse natural and climatic zones of the republic. Data were collected from reindeer herding farms in Olenyoksky, Momsky, Bulunsky, Nizhnekolymsky, and Anabarsky uluses during peak calving periods (April–June). The earliest calving was observed in Nizhnekolymsky ulus, whereas in Anabarsky, Bulunsky, and the northern part of Olenyoksky ulus, mass calving typically begins in early May and concludes in the third decade of May to the first decade of June. The overall calving season lasts 30–45 days (6–9 five -day periods), with 70–80% of females calving within a highly synchronized window of only 3–4 five-day periods. This pronounced reproductive synchrony reflects adaptation to the short favorable season and is influenced by local climatic factors, rut timing, and the physiological condition of breeding females. Early and compact calving holds significant practical value for herds undertaking long nomadic migrations, as early-born calves gain sufficient strength by river breakup and the onset of mass insect emergence, thereby reducing risks of hypothermia, pneumonia, and mortality.
These findings highlight adaptive mechanisms in the reproductive system of reindeer to Arctic environments and offer valuable insights for improving herding technologies, veterinary monitoring, and selective breeding practices in Yakutian reindeer farms.

Animals of all ages may need surgical care. In most cases, elderly patients have chronic diseases and the body's reserve capabilities differ significantly from younger individuals. Age-related involution of metabolic processes, a decrease in the reactivity and adaptive capacity of an elderly body, along with postoperative trauma, pain and stress, significantly increases the risk of postoperative complications and mortality. The purpose of the research is to identify the features of anesthetic and therapeutic measures during keratectomy and removal of an eye neoplasm in a geriatric animal. The research was conducted at the Vetkom Veterinary Clinic in Tyumen in 2025. The article describes a case from practice, using the example of an 18-year-old cat who underwent keratectomy and removal of a neoplasm in the medial corner of the eye. The operation was performed to improve the patient's quality of life. The article presents an anesthetic protocol, as well as treatment regimens before surgery and in the postoperative period. In the process of aging, there is a decrease in metabolic processes, a decrease in the reactivity of the body, which increases the risk of postoperative complications and postoperative mortality. Despite all the physiological changes in geriatric patients, their age cannot be considered a contraindication to anesthesia. The monitoring of physiological parameters during the patient's anesthesia contributed to the favorable course of the operation to remove the neoplasm of the eye. The attentive attitude of the attending physician with regular checkups and recording the dynamics of treatment made it possible to cure this pathology. Therefore, this clinical case is evidence that the animal's condition has stabilized in the postoperative period, and there have been no complaints about its well-being from the owners.

Lesions of the distal extremities in lactating cows can be of both infectious and non-infectious etiology. Finger crumb ulcer or finger dermatitis or Mortellaro's disease and necrobacteriosis are infectious diseases. These diseases can occur if zoogynical rules of maintenance are not followed, if preventive measures are not taken (for example, untimely and poor manure harvesting, absence or improper use of preventive baths). Bacteriological material was taken from sick animals in the area of the finger crumb from five animals. The animal was fixed in a special orthopedic machine. Before taking the biopsy, local anesthesia was performed with a 2% solution of novocaine. The lesion was washed with tap water and dried with sterile wipes. The biopsy was performed at the border of healthy and damaged tissue with a tubular scalpel (punch) with a diameter of 5 mm. The samples were placed in tubes with liquid Ames transport medium. Under isothermal conditions, they were transported to the laboratory for 3 hours. Thus, when studying the culture of biopsies of bovine hoof crumb, a variety of microflora (environment, mucous membranes and skin, potentially pathogenic and purulent microflora, opportunistic fungi) and fungi that can potentially participate in the development and maintenance of inflammation of soft tissues, skin, its appendages and subcutaneous fat were isolated. It can be assumed that the main penetration of microorganisms into the focus of inflammation occurs from the external environment, during pathogenesis, the pathological process is complicated by purulent microflora, which further aggravates and complicates the course of the disease.

Urbanisation of society at the present stage of development is characterised by an increase in the number of small domestic animals and the number of visits by their owners to veterinary clinics, as well as a change in the structure of diseases. In recent years, researchers and practitioners in veterinary medicine have begun to pay increasing attention to a new field: dentistry. This is due to the fact that the incidence of dental diseases in dogs is 10.9% and in cats 9.7%. However, questions remain about their prevalence and causes. Information is limited to individual reports, and the results of studies are difficult to compare due to the heterogeneity of the source material. The aim of the study was to monitor dental diseases in dogs and cats in Kostroma. The research was based on data from the VetManager automated information system, which allows the VetLife veterinary clinic to maintain electronic medical records for all small pets (dogs and cats) initially admitted between 2022 and 2025. The diagnosis of patients with signs of dental diseases was made on the basis of anamnesis and the results of general and special (X-ray, etc.) research methods. It was shown that dental pathologies account for 9.49%, with dogs and cats accounting for 49.15% and 50.85%, respectively. Periodontitis (37.68%) and tartar (23.52%) are most commonly recorded in dogs, while gingivostomatitis (26.89%) is most common in cats. In addition, the number of patients diagnosed with periapical abscesses increased significantly (by an average of 7.24%) in both species. Dental pathologies were most frequently recorded in the spring and autumn periods. The data obtained indicate the need for a more detailed study of this issue.

The effect of the equine MSCs secretome on the ability to induce thrombosis in vitro was studied by visually assessing platelet aggregation under the action of this drug on a slide using the A. S. Shitikova method, observing the process under phase contrast. The effect of secretome on thrombosis in vitro was determined on platelet plasma isolated from horse blood with the anticoagulant sodium citrate. Saline solution (control 1), 10.0% calcium chloride solution (control 2), a secret in the proportion of 10 parts of the volume of plasma enriched with platelets to 1 part of the secretome (experiment 1), a secret in the proportion of 20 parts of the volume of plasma enriched with platelets to 1 part of the secretome (experiment 2) were added to tubes with platelet plasma, a secret in the proportion of 20 parts of the volume of plasma enriched with platelets to 1 part of the secretome and 10.0% calcium chloride solution (experiment 3). After adding control and experimental preparations to platelet plasma samples, 10.0 µl of the mixture was microscoped at X400 magnification using phase contrast. As a result of our research, data were obtained indicating that the secretome of horse MSCs lacks the ability to induce platelet aggregation. Platelet-rich plasma obtained from horses (n=10) with sodium citrate showed no signs of aggregation, unlike platelet-rich plasma with sodium citrate activated with calcium chloride. When secretome was added at concentrations of 10 to 1 (10 parts of platelet-rich plasma volume to 1 part of secretome) and 20 to 1 (20 parts of platelet-rich plasma volume to 1 part of secretome), platelet aggregation was also not observed. At the same time, when calcium chloride was added to a platelet-enriched plasma sample with the addition of secretome, platelet aggregation was within the normal range.

Some strains of Escherichia coli are pathogenic in dogs and cats, causing gastrointestinal and extraintestinal diseases, including urogenital tract infections. The presence of extended-spectrum β-lactamases (ESBL), an enzyme produced by gramnegative bacteria, makes these bacteria resistant to almost all β-lactam antibiotics (penicillin’s, cephalosporins), significantly complicating the treatment of the infectious process. Urinary tract infections (UTIs) caused by bacterial pathogens are among the most common infections in dogs. Their development is often associated with the migration of bacteria through the genital tract and urethra into the bladder. Sources of infection can include the perianal area contaminated with bacterial biota, as well as overhanging skin in the area of the loop (depressed loop) in females. The spread of bacteria to the bladder, involving the ureters and kidneys, is a complicated, lifethreatening pathology. Clinically significant infection implies the presence of clinical abnormalities and is characterized by dysuria, stranguria, hematuria, pollakiuria and/or frequent urination, as well as the presence of bacteria in the urine. However, long-term, chronic bacterial infections may have minimal clinical signs and remain undetected for a long time. Accurate and timely diagnosis is crucial for UTI treatment. It allows for the determination of both the need for antimicrobial medications and their optimal dosage. This includes an assessment of the patient's condition, a thorough examination, and collection of a clinically relevant history, which must include information about previous surgeries, blood and albumin transfusions, as well as previously diagnosed and concomitant diseases, complaints, and symptoms. When collecting the history, it is also important to clarify any previously prescribed antibacterial medications and the duration of their use. To effectively treat UTIs, it is necessary to identify the predominant bacterial pathogens and their susceptibility to antibacterial agents. A urine culture will be key to establishing a diagnosis and therapeutic strategy.

According to various literary sources, the development of enteropathies in dogs in metropolitan conditions reaches 76-84%. Diseases of the digestive tract in animals are a pressing problem, and their treatment is one of the most important tasks in veterinary medicine. A crucial factor in healthy digestion in dogs is the normal composition of the intestinal microbiota, which is highly dependent on the diet. Therefore, it is essential to consider this aspect when creating and prescribing therapeutic diets. The aim of this study was to investigate the impact of the new veterinary diet "Academia" with added probiotics and prebiotics on the intestinal microflora of dogs with digestive disorders, including exocrine pancreatic insufficiency, produced by JSC Gatchina Feed Factory. The study presented a three-month experiment using a veterinary diet in dogs with digestive disorders. The article examines the effect of probiotics and prebiotics on the composition of the intestinal microbiome and analyzes changes in the microbiome of the rectal contents of the study animals by culturing the samples on selective nutrient media and determining the number of microbial bodies and the species composition of the microflora. As a result of the study, it was found that the veterinary diet under study has a positive effect on the intestinal microflora, as it reduces the number of opportunistic pathogens in most of the samples compared to the pre-diet studies. Additionally, the diet has a beneficial effect on increasing the number of "beneficial" microorganisms (bifidobacteria and lactobacteria) in the intestines. It was also noted that the best results were achieved by using a mixed diet that combines dry and wet food.

Infectious bronchitis of chickens causes enormous economic damage to poultry farming, which consists of poultry deaths, decreased egg productivity, decreased body weight gain, low feed conversion, etc. IB of chickens often occurs in association with other viral infections, and the course is always complicated by signs of secondary bacterial infection. There are more than 100 serotypes of the IB of chicken’s virus, the appearance of which is due to changes as a result of point mutations in the S1 gene subunit of the S protein, which lead to the emergence of new properties in the field virus. Moreover, acquired immunity to one serotype often does not provide protection against infections with other serotypes of the IB of chicken’s virus. To detect antibodies to certain serotypes of the IB of chicken’s virus. To isolate the IB of chickens virus, 3-4 passages are carried out on 9-10 day-old chicken embryos by infection into the allontoid cavity, but the associated course of IBC with other viral infections, the appearance of new variants and strains of the virus makes it difficult to conduct diagnostic studies using classical methods, while the use of RT-PCR followed by sequencing of the nucleotide sequence of the S1 gene of the IBC virus makes it possible to identify and differentiate the pathogen, which is important for the prevention of this disease. In case of IBD in the household, timely diagnostic, therapeutic, preventive measures should be carried out using specific preventive measures. The combined use of live and inactivated vaccines ensures the formation of a stable immune response sufficient to protect livestock from the field virus throughout the productive period.