Veterinary specialists guard the health of not only the animal world, but also, by performing their work duties properly, make a significant contribution to human health, which, however, is not adequately reflected in the norms of law. The article examines and systematizes the existing measures of criminal, administrative and civil liability. Analogies are drawn with the norms applicable to healthcare workers. Legislative measures have been proposed that will contribute to the prevention of offenses in the activities of veterinary specialists, as well as the humane treatment of animals.
Despite the variety of existing sanctions against veterinary specialists, the legislator can pay attention to some proposed measures to prevent possible violations of the law and guarantee the principle of humane treatment of animals. 

The article presents the regulatory and legal aspects and modern requirements for the quality and safety of organic products in their production. Standards, technical regulations and Federal Laws adopted in recent years establish definitions in the field of production, composition of organic products, labeling and packaging requirements. The interstate standard GOST 33980-2016 for organic products specifies the rules for organic livestock farming, organic crop production, the fish organic industry, beekeeping and other areas of agriculture.
The article discusses some of the most significant, in the opinion of the authors, changes and additions to the standard.

The issue of circulation of livestock by-products is currently a topic for discussion and consideration in the field of agriculture. There are inaccuracies in the legal aspect, which also occur after the adoption of a number of regulatory legal acts. These points require careful consideration and require some recommendations aimed at correcting the difficulties that have arisen, which are reflected in judicial practice. This work examines the main body of laws, derives the definitions given in them from the point of view of long-term development to the best interpretation, and also provides a clear vector for research on the topic of shortcomings, touching on the topic of turnover of life expectancy and its connection with actively functioning personal subsidiary plots. We also show the opportunity for owners of private household plots to pay attention to recent changes in legislation in order to prevent possible offenses. At the moment, small and medium-sized enterprises in the livestock sector find themselves in a difficult situation, and therefore we offer a possible option for resolving difficult inconsistencies that arise.

Raw cow's milk has high nutritional and dietary value. Raw milk obtained from sick animals, as well as milk produced in violation of hygienic, sanitary and technological norms and rules, can cause human poisoning, infection with zooanthroponous and foodborne diseases. This article presents recommendations on the organization and conduct of veterinary examination of milk and its veterinary and sanitary assessment, based on a documentary analysis of the requirements of the technical regulations of the Customs Union CU TR 033/2013 and TR CU 021/2011 and the veterinary rules for the appointment and conduct of veterinary and sanitary examination of milk and dairy products intended forworks or for sale in retail markets dated 06/28/2021, as amended on 05/24/2022. Based on the results of studies of the rules of veterinary and sanitary examination of milk dated 06/28/2021. Based on the results of studies of the rules of veterinary and sanitary examination of milk dated 06/28/2021, we found that they do not require the determination of such indicators in milk as: the group of milk purity, the presence of inhibitory substances and the freezing point of milk, although these indicators are present in TR CU 033/2013, at the same time, the rules prescribe the determination of coli titer in raw milk, while time, as in the Technical Regulations, this indicator is not prescribed for raw milk.

Intensive technologies of animal husbandry imply the maximum use of productive qualities of animals, the realization of which is hindered by diseases of various genesis, especially those that are accompanied by a long chronic course. Genital mycoplasmosis of cattle occupies a special place among them. The aim of our research was to study the protein spectrum of blood serum in patients with genital mycoplasmosis of the blood when used for the treatment of tulatromycin and tulatromycin in combination with thymalin. To conduct the experiment, three groups of pregnant cows were formed, 8 heads each. The first group – pregnant cows with genital mycoplasmosis for the treatment of which the antibiotic traksovet 100 (tulatromycin) was used. The second group - pregnant cows with genital mycoplasmosis for the treatment of which the antibiotic traksovet 100 and the immunomodulator timalin were used. The third group (control) – clinically healthy pregnant cows. In all groups of animals , blood serum was determined: the content of total protein, albumins, globulins and immunoglobulins of classes G, M, A. Antibiotic therapy of patients with genital mycoplasmosis of cows leads to the elimination of the pathogen from the genital tract in 75% of animals, whereas with a combination of an antibiotic and an immunomodulator, mycoplasma was not detected in any animal from the group. The use of tulatromycin for the treatment of cows with genital mycoplasmosis leads only to a partial normalization of the protein spectrum of blood serum, whereas the use of a combination of tulatromycin and thymalin for the treatment provides a complete restoration of the studied parameters to the level of clinically healthy animals.

Computer models in veterinary medicine are used in veterinary medicine to simulate the spread of infectious and noncommunicable diseases, predict the consequences of the disease, plan, evaluate epizootic surveillance, control strategies, and obtain information about cause-and-effect relationships by comparing the results of the model with real-life data. There are various types of disease spread models, and this review article presents and describes the implementation of a certain type of disease - models based on an individual approach. The purpose of the review work is to develop models for the spread of infectious and non-communicable animal diseases based on an individual approach, their use and problems.The materials of the review article are based on the results of numerous epizootological, diagnostic studies, methods of mathematical statistics by scientists from Denmark, Ireland, Switzerland, Australia, Great Britain, Germany, Sardinia. Examples of programming languages and code are provided in order to make modeling methods more accessible to users. Important steps in building such models before, during, and after the programming phase are described, including: model verification to ensure that the model does what it was intended to do; model validation to determine whether the model results reflect the system being modeled; model convergence analysis to ensure its compliance with endemic diseases. A brief analysis of the sensitivity of the model is given, which is used to identify parameters and processes that have a significant impact on the predictions of the model. A brief overview of some interesting recent developments in the field of disease propagation models is provided.

Storage of industrially valuable strains of microorganisms is one of the strategic tasks of modern science and the biological industry. The production and timely implementation of therapeutic, preventive and diagnostic drugs against anthrax contributes to maintaining a stable epizootic situation in Russia for this disease. Therefore, the development and study of methods for storing industrially valuable strains of Bacillus anthracis is an important research work that allows preserving and preserving the unique biological properties of the cells of this pathogen. The purpose of this work was to study the preservation of the viability and biological properties of the Bacillus anthracis strain after 12 months of low-temperature preservation. The strain K-STI-79 of the causative agent of anthrax was used in the work. The strain was stored for 12 months at a temperature of minus 70 C in two cryoprotective media: 15% glycerin solution with 15% glucose solution and 30% neutral glycerin solution in saline solution. After 6 and 12 months of storage, the cells were removed from preservation, thawed at 37 C, tenfold dilutions were made in sterile saline solution and seeded to determine the concentration of viable cells. The safety of the biological properties of the pathogen was studied according to MUC 4.2.2413-08. As a result of the work, it was found that the selected cryoprotectors and the temperature regime of storage allowed to keep a high number of cells in a viable state, which did not significantly differ statistically from the initial concentration. The study of the biological properties of the strain showed their compliance with passport data. The conducted work demonstrates the possibility of effective use of the applied scheme of low-temperature preservation of Bacillus anthracis strains for 12 months.

The use of antimicrobial drugs and vaccinoprophylaxis are the main ways to prevent and combat most bacterial diseases. However, the unsystematic use of antimicrobials without taking into account the sensitivity of pathogens to drugs often does not allow achieving the desired results. On the other hand, the use of a properly selected vaccine, taking into account the epizootic situation in the farm, is one of the safe and effective tools for controlling diseases of bacterial etiology.
In this regard, the results presented in this article of testing samples of vaccines against bacterial diseases of birds, made on the basis of a modern oil adjuvant ICTYOLANETM 11, are interesting and timely.
For research three vaccine samples were manufactured based on the oil adjuvant ICTYOLANETM 11. The first sample of the vaccine is against avian salmonellosis, the second is against avian pasteurellosis and the third is against avian respiratory mycoplasmosis.
Analysis of the results showed that all vaccine samples made on the basis of the oil adjuvant ICTYOLANETM 11 met the specified parameters in terms of viscosity and stability, ensured the formation of humoral immunity of the required level and fully met the requirements for drugs of this class.
But along with good physico-chemical and immunological indicators, vaccines against salmonellosis and pasteurellosis of birds showed reactogenic properties to one degree or another, while the vaccine against respiratory mycoplasmosis of birds was areactogenic.
Based on the obtained research results, it can be concluded that the use of the adjuvant ICTYOLANETM 11 in the production of a vaccine against avian respiratory mycoplasmosis makes it possible to obtain a safe and effective immunobiological preparation.

The article presents materials on the foundation, equipping and functioning of mobile district veterinary stations of the Government Veterinary Service Department of the Republic of Tatarstan. Their experience within 2018-2022 on providing veterinary service of agricultural cattle breeding enterprises, farms and private subsidiary farms in the republic settlements was summarized. 

The review article presents the relevant results of comprehensive studies aimed at studying the toxins of Bacillus anthracis. The structural features of protective antigen, lethal and edematous factors are shown. The mechanism of translocation of a complex of toxins into the cytosol of the cell is presented. The orientation of the action of lethal and edema toxins on the cells of a susceptible organism and the mechanisms of their cytotoxicity are analyzed. The mechanisms of action of toxins in the early and systemic stages of infection are described. Issues have been identified regarding the interaction of toxins with target cells and their effects on various organs and tissues of the macroorganism, which require further in-depth studies.

A bacteriological study of pathological material from cows in livestock farms of the Leningrad region was conducted. The following were examined: mastitis milk, vaginal swabs, blood, internal organs, manure, silage. 267 cultures and 11 species of pathogenic and opportunistic microorganisms have been isolated and identified. The maximum distribution is accounted for by staphylococci – 36.33%., among which are more common: golden Staphylococcus aureus, white Staphylococcus epidermidis and lemon yellow Staphylococcus citreus. In second place in terms of prevalence was a microorganism from the Enterobacteriaceae family – Escherichia coli – 20.6%. When analyzing the isolated microflora in each individual farm, it is possible to identify the dominant microflora. This study showed that mixed infections are more common and there is an associative effect on the animal's body. When analyzing the isolated microflora in a separate farm, it is possible to identify the dominant microflora.
Farms have their own microbial landscape, which must be taken into account when prescribing antibacterial therapy. Conducting a bacteriological study to isolate the pathogen and determining antibacterial sensitivity helps to prevent the formation of resistance in microbes to antibiotics.

The article analyzes the spectrum of diagnostic methods for establishing the invasion of dirofilariasis, describes the mechanisms of development of the epizootological situation of dirofilariasis, the complication of which is facilitated by the climatic features of the region and the lack of a clear algorithm for prevention. In order to increase the effectiveness of preventive treatments against the main vectors (mosquitoes), the calculation of the season of maximum infection with dirofilariae in the Ararat region of Armenia was carried out. Entomological exploration was carried out in order to establish the species composition of mosquitoes and the main vector of Aedes caspius was determined. A system of antiepizootic and preventive measures for dirofilariasis of dogs in the Ararat region of Armenia has been developed, which includes two lines of protection: the first line of protection includes preventive deworming with drugs from the group of macrocyclic lactones, the second group of protection consists of repellent agents (pyrethroids, cyflutrin, piperonylbutoxide and diflubenzuron).

One of the effective ways to deacarize livestock premises is the use of aerosol checkers based on various active substances. This method provides a large coverage area and does not require additional equipment which simplifies its further use unlike the irrigation method. One of these tools is a low-temperature smoke generator "SMOKE insect" developed by LLC "Agrovetzashchita". Cyflutrin – the main active ingredient contained in the composition of the product provides a pronounced contact effect against ectoparasites affecting the nervous system and contributing to further paralysis and death of the insect. The purpose of the research was to test a low-temperature smoke generator "SMOKE insect" during the deacarization of poultry farming premises. For processing, these generators were used containing 40 g of the active active ingredient – cyflutrin. The product was used in the production premises of an egg-type poultry farm. During the tests 4 rooms were involved, each with a volume of 8000 m3. The quality control of deacarization was carried out by monitoring the appearance of a red chicken tick in a poultry house. The observations lasted 9 months. When analyzing the obtained research data it can be concluded that smoke generators showed a high acaricidal effect in the treatment modes of 640 and 960 g. per room with a volume of 8000 m3. With similar efficiency it is advisable to use the "SMOK insect" agent in the processing mode of 640 g. for a room with a volume of 8000 m3 which corresponds to the treatment of 500 m3 with a single smoke generator.

In recent years, dairy farming has been actively developing in Russia in many directions, providing consumers with milk, dairy products, meat and other raw materials. Particularly relevant are the automation of the processes of raising cattle and the selection of the most economically profitable dairy and meat breeds, which is facilitated by the development of artificial insemination in this agricultural sector. The success of artificial insemination is determined by many factors, including the quality of sperm extenders used and the correctness of cryopreservation protocols. The purpose of this study is to test a protocol for cryopreservation of Holstein bull sperm. The ejaculate was collected, evaluated, and pre-prepared (centrifugation, dilution, cooling). The freezing process was carried out using the method presented in the article by AnsariM.S., RakhaB. A. et al. (2015) for buffalo sperm: the straws were kept above liquid nitrogen vapor at a distance of 5 cm for 10 minutes, and then immersed in a Dewar flask. Sperm motility was assessed 3 times: after sperm collection, after cooling, and 0 hours after thawing. The negative impact of the cryopreservation process on the morphofunctional characteristics of sperm was determined. The study noted a decrease in the motility of progressively moving sperm by 21.53%, as well as a sharp increase in immobile sperm before and after cryopreservation from 6.8% to 33.82%. The number of nonprogressive spermatozoa was reduced from 9.12% to 2.91%. Changes in the morphological parameters of sperm as a result of cryopreservation (after cooling and 0 hours after thawing): the number of normal sperm decreased by 12%, the number of sperm with tail defects increased by 11% and head by 2%. Based on the data obtained, we can conclude that the use of this cryopreservation protocol, with preliminary preparation, helps preserve sperm viability. Further research will be aimed at studying and creating cryoprotectors that increase the safety of sperm of breeding bulls during deep freezing.

In recent years, due to the increase in the consumption of dairy products, the need to increase the productivity of animals has increased. One way to achieve this goal is to inseminate the heifers early. In the context of a specific production technology, it is necessary to establish the optimal, most profitable terms for the initial sexual use of heifers.
Studies have been conducted to examine the milk productivity and duration of use of heifers inseminated at 12 months of age compared to animals at a later date of insemination.
Analysis of live weight changes during growth showed that heifers of the 1st group grew intensively at all age periods, ahead of peers in live weight. The study of milk productivity indicators showed that for 305 days of the 1st lactation and for the entire lactation, animals of the 1st group (early insemination) were infeIn recent years, due to the increase in the consumption of dairy products, the need to increase the productivity of animals has increased. One way to achieve this goal is to inseminate the heifers early. In the context of a specific production technology, it is necessary to establish the optimal, most profitable terms for the initial sexual use of heifers.
Studies have been conducted to examine the milk productivity and duration of use of heifers inseminated at 12 months of age compared to animals at a later date of insemination.
Analysis of live weight changes during growth rior only to animals of the 2nd group in the amount of milk, but differed in high fat content (3.93%). The yield on the 1st day in animals of the 1st group was lower by 0.4-0.8 kg. According to the results of the 2nd lactation, there were no differences in productivity between animals of different groups.
Analysis of data on the duration of use of dairy cows of different insemination ages showed that under the current conditions of feeding, keeping and using animals in the study farm, cows with an early insemination period (12.0 months) were used longer than others - 1.4 lactation.
The body sizes of the first calves, namely the width in the sacrum, were estimated in animals of the 1st group by 3 points, which is worse than in the first calves of other groups.

Cryopreservation of rooster semen has found wide application in creation of reproductive cell’s cryobanks. Compare to other farm animal’s semen, quality of frozen/thawed bird semen are often lower. This factor makes choice of individual ejaculates for the purposes of cryopreservation more difficult. In our study, we considered the possibility of improving frozen/thawed semen performance by adding enzymatic antioxidants to diluents. It has been shown that during the vitrification of reproductive cells, the addition of exogenous enzymatic antioxidants reduces the destructive effect of reactive oxygen species, which indicates the possibility of improving method by reducing oxidative stress to cells. When added to the diluent for cryopreservation rooster’s sperm LKS-1 superoxide dismutase in amount of 75 IU cell viability increased by 3,65 %, when was added catalase in amount of 200 μg/ml, cell viability increased by 5,27 %.

The studies were conducted on lactating cows of Red-Motley Holstein and Simmental breeds with subclinical mastitis aged from 1 to 8 lactations. Four groups of animals of 10 animals each were selected. The first group was treated with the complex ointment “Uberosept” once a day, externally for 5 days. The second group received “Uberosept” 1 time per day, externally for 5 days, “Mixoferon” 3 ml intramuscularly 2 times a day for 7 days. The third group received “Uberosept” 1 time per day, externally for 5 days, “Submastin-KRS” 10 ml intramuscularly 1 time per day for 3 days. Blood samples were taken from all experimental groups to study morphobiochemical indicators and indicators of lipid peroxidation, antioxidant protection and endogenous intoxication. The samples were taken before treatment, immediately after the course of treatment and 7 days after treatment. The highest therapeutic effectiveness of the treatment regimen for subclinical mastitis used in the second experimental group was 90.0%. In the first experimental group, the therapeutic effectiveness was 60.0%, in the second experimental group - 80.0%. This was confirmed by morphobiochemical studies; in the group of animals that were injected with “Mixoferon” + complex ointment “Uberosept”, immunity indicators were higher than in the group of cows that were treated with “Submastin-KRS” + complex ointment “Uberosept”. At the same time, in the animals of the third experimental group, a more pronounced decrease in the processes of endogenous intoxication, lipid peroxidation and activation of antioxidant protection was observed.

Aim. Comprehensive analysis of the morphofunctional state of somatic (cumulus) and germ cells (oocytes) of Sus scrofa domesticus subjected to intraovarian vitrification using silicon dimethylglycerolate (SDMG) are presented.

Materials and methods. Fragments of porcine ovaries (FsPO) 15×20 mm in size were gradually kept in cryoprotective agents (CPA) prepared in phosphate-buffered saline (PBS) with 20% fetal bovine serum (FBS): 25 min. in CPA-1 [7.5% EG (ethylene glycol) with 7.5% DMSO (dimethyl sulfoxide)] and 15 min. in CPA-2 (15% EG with 15% DMSO and 0.5 M sucrose). The composition of the CPA-2 in experimental groups was modified by addition of SDMG (at concentrations of 2%, 6%, or 10%). FsPO were stored in liquid nitrogen. FsPO were devitrified by exposure 1 minute in solution 1 (80% PBS, 20% FBS, 0.5 mol/l sucrose) and 5 minutes in solution 2 (80% PBS, 0.25 mol/l sucrose). The following indicators of cryoresistance of devitrified cumulus-oocyte complexes (COCs) were analyzed: degree of cumulus cells expansion; oocyte morphology and the functional status of lipidome in female gametes (fluorescence intensity of Nile red /lipid droplets complex - FILDs).

Results. The addition of SDMG into cryoprotective media reduced the level of denuded oocytes after vitrification. The level of gamete with different degree of cumulus cells expansion (low, medium, high) in the experimental group with 10% SDMG tended to indicators in the group of native cells. The level of native oocytes with the signs of morphological degeneration (7.7%) had no significant differences with the level of intraovarian vitrified gametes with 10% SDMG (11%). The proportion of native oocytes with low FILDs (38.9%) exceeded the level of oocytes with the above indicator in vitrified oocytes of the control (16.5%) group and in experimental groups of cells with the addition of 6% SDMG (4.8%) and 10% SDMG (11.8%, P<0.001).

Conclusion. In general, comprehensive monitoring of indicators cryoresistance of COCs in Sus scrofa domesticus subjected to intraovarian vitrification revealed the cryoprotective properties of SDMG. The effects were dose-dependent and were expressed in the stabilization of oocyte-cumulus communication, a decrease in the level of oocytes with the signs of morphological degeneration, and features of the lipidome functioning in intraovarian vitrified female gametes using SDMG at various concentrations.

The article presents an analysis of the work carried out on the basis of dairy farms in the Smolensk region for the period from 2008 to 2022. The application of new antimastitis drugs annually was carried out in order to prevent the formation of resistant strains of microorganisms, the main causative agents of mastitis and the selection of modern medicines for highly effective therapy of breast disease, as well as to create stable immunity and general resistance of the organism of lactating cows.
Over the years of research, the high therapeutic efficacy of medicinal products was observed in the range of 82.3 - 98.2% and was evaluated in three days of treatment of cows with mastitis.
Among the medicines used, the most effective were colimast and multiject 98.2% (2017), primalact 96.7% (2020), mastinone 95.0% (2019). When the were used, the signs of the inflammatory process of the mammary gland disappeared gradually, but by the 3rd day of treatment, milk secretion was completely restored and the condition of the animal as a whole improved significantly.

The use of Expert Renal PSC in the complex therapy of dietary diets for adult cats of all breeds led to a decrease in urea level by 1.7 times, creatinine by 29%. The decrease in protein in the diet made it possible to reduce the content of inorganic phosphorus in the blood of experimental animals by 20%. It can be concluded that the use of Expert Renal PSK dietary diets for adult cats of all breeds in the complex therapy of chronic kidney disease, initiated at stage 2, contributes to the stabilization of kidney function and reduces the progression of renal failure.

Veterinary medicine at the present stage of development requires the search for new ways to assess the lesions of the musculoskeletal system. Due to the need for a clear detailed differentiation of types and types of neuropathies, new methods of functional diagnostics are being introduced into veterinary practice, one of which is an electroneuromyography (ENMG) examination. This diagnostic method is the most complete, reflecting the state of both nervous and muscular structures. The issue of this study is to determine the type of neuropathic pathology: axonal or demyelinating. During the measurements carried out, typical electrophysiological markers characteristic of different types of neuropathic pathologies were noted in the studied animals. Together with the neurological examination, the type of peripheral neuropathy was determined for each animal, on the basis of which the most effective treatment regimen was selected in the future.

The article is devoted to evaluating the effectiveness of methods for diagnosing foreign objects in small domestic animals in the digestive tract radiography, esophagogastroduodenoscopy, ultrasonography. The algorithm of conducting diagnostic studies in case of suspected presence of foreign bodies of the gastrointestinal tract depends on the localization, physical characteristics and configuration of foreign bodies. It was found that a more informative endoscopic examination allows to determine the location of a foreign object, to assess the condition of the mucous membrane of the digestive tract organs simultaneously and after their extraction. However, the jejunum and the large intestine cannot be fully evaluated by the endoscopic method.

The results of a study of changes in some laboratory parameters and the use of instrumental research methods for ovarian leiomyoma in dogs are presented using the example of a clinical case. The animal observed increased frequency of urination, episodes of enuresis, and an increase in abdominal volume. It was determined that there are no special morphological changes in the blood associated with leiomyoma, but pronounced lymphopenia of unknown origin was determined. Urine examination also did not reveal significant deviations in its composition. An ultrasound examination revealed a solid formation in the area of the left ovary measuring 15.22*9.80 cm, displaced towards the spleen, hypoechoic, with areas of heterogeneous echogenicity, its contours are unclear. During intraoperative removal of the tumor and its histological examination, a benign formation was revealed - leiomyoma. It is a tumor of diffuse structure, formed by chaotically intertwined, distinctly arranged, large bundles of spindle-shaped cells. Tumor cells are long, elongated, with well-defined eosinophilic cytoplasm, with indistinguishable cell boundaries. The nuclei are medium-sized, elongated, normochromic and lightcolored, with finely dispersed chromatin. Cellular and nuclear polymorphism is weakly expressed, single mitoses are detected. In bundles of tumor cells, a large amount of eosinophilic matrix is detected, visually merging with the eosinophilic cytoplasm of the cells.

Among the methods that make it possible to obtain and evaluate biochemical indicators that characterize the direction of metabolism, the state of health and the course of the pathological process in the body, the blood examination occupies an important place. There are several ways to take blood in animals and birds. The literature often describes the classic methods of one -time obtaining blood in animals and birds. And if in the case of animals serial taking blood became a routine method, with birds, due to increased blood coagulation, the situation is more complicated. To ensure convenient access to venous vessels in order to obtain serial blood samples to study biochemical indicators in dynamics, the use of peripheral venous (intravenous) catheters is recommended. The use of catheter makes it possible to minimize a stress factor in birds, which is inevitable when using a syringe with each piercing of a vein, as well as avoiding the occurrence of hematomas. The catheterization method has been used for a relatively long time, however, when installing catheter on chickens, there are a number of unresolved issues on the correct selection of catheter and their correct use.
In this regard, the purpose of the work was the approval of the use of peripheral venous catheter for interval capture of blood. During the testing of the method, it was found that, despite the increased blood coagulation of chickens, the correctly selected catheter is not clogged with blood clots. Therefore, for the selection of a catheter of the optimal size, it is necessary to take into account the size of the covering vein, because The catheter incorrectly selected in size can lead to injury to the vein (with the prevailing diameter of the catheter over the diameter of the vein), or to the blockage of the catheter (with a small diameter of the catheter). For catheterization of the covenant vein of chickens, the use of peripheral venous catheter with the dimensions of the G22 and G24 is recommended.

In order to validate the methods used to determine the toxicity of drugs, researchers usually turn to the most authoritative scientific literature, the system of state standards, or alternative systems. One of them is the OECD (Organization for Economic Co-operation and Development) regulations on testing chemicals.
The article provides a brief analysis of the OECD regulations for testing chemicals (in particular, Chapter 2 “Effects on Biotic Systems” and Chapter 4 “Effects on Health”), which is a set of internationally recognized specifications for testing chemicals approved by the Organization for Economic Co-operation and development.
The basic principles of conducting an experiment, the requirements for biological models for research, and the general system for assessing a particular type of toxicity were assessed.
The main benefit of applying the OECD regulation in the context of toxicological studies is that it ensures uniformity of approaches and methodology in assessing chemical safety at the international level. This facilitates the comparison of research results, as well as the exchange of information between countries and organizations. Data quality control and adherence to GLP principles also provide confidence in research results, which is the basis for decision-making in chemical regulation and the protection of human, animal and environmental health. In general, OECD regulations in the context of toxicological research play an important role in ensuring safety and protecting public health and the environment. It provides standards and recommendations that facilitate the effective assessment of chemical safety and the development of appropriate measures to ensure it.

Pharmaceutical companies face global competition, economic instability, regulatory restrictions, rising costs, patent restrictions and generic drug production. Despite the fact that the most important conditions for the release of analogues within reference countries and registration of drugs for bioequivalence are commercial factors, a clear regulatory framework and post-marketing data are required.
The purpose of this work is an international review of enterosorbents based on the active substance in Russia and other EU countries, an overview of the modern veterinary market and a reflection of development trends in the pharmaceutical market for this group of drugs.
The evaluation included both medicinal products and feed additives. To evaluate medicines and feed additives of the sorbent group, by active ingredients, we analyzed the Unified Register of Registered Medicines of the Eurasian Economic Union [4], the Register of Registered Medicines for Use in Veterinary Medicine, Diagnostic Systems, Means for Antiparasitic Treatments of Animals and Feed Additives. During the research, methods of statistical analysis and content analysis were used. Based on data from state registers of Medicines for veterinary use in Russia (URL: https://galen.vetrf.ru), Belarus (URL: http://www.dvpn.gov.by), Kazakhstan (URL: https:// gov.kz) and Armenia (URL: http://www.pharm.am).
Thus, after conducting statistical analysis and content analysis, it was concluded that the distribution of drugs depends primarily on the needs of the market of a given country and the solution of the tasks assigned to doctors and production. Thus, a large number of feed additives, which contain sorbents, are registered in the Russian Federation, and are completely absent in the Republic of Armenia.

The design of drugs that allow the unlimited use of animal products is an important area of veterinary pharmacology. In this regard, in the production of a new complex ointment intended for treating the skin of the udder of cows, natural components were selected. The formula for “Uberosept” ointment includes ichthyol, pine resin and camphor. One of the important stages of preclinical study of new drugs is to identify their toxic properties and evaluate their efficacy. Therefore, the purpose of our work was to determine the toxicity class and study the wound-healing effect of “Uberosept”.
The acute toxicity of “Uberosept” ointment was tested during intragastric administration using a fixed dose method (GOST 32296-2013) on female white mice. The wound healing effect was studied in a full-thickness skin wound model in female rats.
It has been established that “Uberosept” ointment can be classified as hazard class 5. When administered intragastrically at a maximum dose of 5000 mg/kg during the first 30 minutes and the next 14 days, no signs of intoxication were detected in all experimental mice.

Preclinical testing of the new drug «Prazid®-complex», developed by LLC «Apisenna» (Russia, Moscow, Smolenskaya-Sennaya sq., 27, building 1A, apartment 74), containing 102 mg of praziquantel in 1 ml, 5 mg ivermectin, 100 mg of fipronil and excipients were carried out on non-linear laboratory mice purchased from the branch of the National Research Center «Kurchatov Institute» PNPI - PLZh «Rappolovo». The acute toxicity of the drug was determined according to GOST 32644-2014 and «Guidelines for experimental (preclinical) study of new pharmacological substances» (2005)» on 6 mice (3 females and 3 males in each group. To determine the LD50 of the drug, five experimental groups of six animals each (3 males and 3 females) were formed from 30 mice. To calculate the parameters of acute toxicity, we used the method of determining LD50 using probit analysis according to Litchfield and Wilcoxon, which is based on taking into account the mortality of animals from administered doses of the drug under study. The hazard class of the drug was determined according to GOST 12.1.007-76. It was found that the drug «Prazicide®-complex» in doses of 2.0; 3.5; 5.0; 6.5 g/kg causes death in 100% of experimental animals within 24 hours.
When the drug is administered at a dose of 0.5 g/kg body weight for 14 days, death is observed in 50% of experimental mice. LD50 of the Prazitsid®-complex drug is 0.5 g/kg body weight. According to the classification (GOST 12.1.007-76), the drug «Prazid®-complex» should be classified as a low-toxic compound (hazard class 3) and used for clinical trials on animals.

In veterinary pharmacology, radiopharmaceuticals play a key role in the diagnosis and treatment of various diseases. These are special preparations containing radioactive isotopes, which provide high sensitivity and accuracy of visualization of internal organs and tissues as part of radionuclide diagnostics. In this regard, the production and use of radiopharmaceuticals requires strict adherence to certain requirements that ensure the safety and effectiveness of their use.
Regular monitoring and safety assessment of the use of radiopharmaceuticals in veterinary medicine are mandatory measures to maintain a high level of professional animal care and protect the environment.
The article discusses the main regulatory documents regulating the production and use of radiopharmaceuticals.
In general, requirements for the production and use of radiopharmaceuticals are aimed at ensuring the safety of animals, personnel and the environment, as well as guaranteeing the high quality and effectiveness of the drugs used. Only strict compliance with all requirements will allow the medical community to fully exploit the potential of radiopharmaceuticals for the diagnosis and treatment of various diseases.

L-carnitine is a vitamin-like compound that is synthesized in the human or animal body from the amino acids methionine and lysine. Today, L-carnitine is used in cardiology, neurology, gastroenterology and is a substance necessary for the functioning of the body. It normalizes metabolic processes, stimulates cellular energy exchange, eliminates energy deficiency, strengthens the immune system, relieves overwork and fatigue, increases the body's adaptive capabilities, and reduces muscle weakness. Protected L-carnitine is used in dairy farming for metabolic diseases, but only as a feed additive.
The purpose of our research is to study the injectable form of L-carnitine, which has not previously been registered in the Russian Federation.
Toxicity studies were conducted on outbred rats in October 2021 in the vivarium of the St. Petersburg State University of Veterinary Medicine. The study involved females weighing 190-210 grams, purchased from the Federal State Unitary Enterprise “Nursery of Laboratory Animals “RAPPOLOVO”. When studying subchronic toxicity when administered subcutaneously, L-carnitine was administered at 2 dose levels. Doses were determined based on the results of the acute toxicity experiment: 1/5 and 1/10 of the maximum tolerated dose. The first experimental group (n=10) received the drug subcutaneously at a dose of 0.08 mg/kg (1/5 of 2000 mg/kg). The second experimental group (n=10) received the drug subcutaneously at a dose of 0.04 mg/kg (1/10 of 2000 mg/kg). The control group (n=10) received subcutaneous sodium chloride 0.09% at a dose of 1/5 of 2000 mg/kg. The drug was administered subcutaneously daily for 42 days. Slaughter and sampling of biological material from 5 animals from each group were carried out the next day after the end of the drug administration (day 43), and 10 days after the last drug administration (day 53).
As a result of studies of subchronic toxicity on laboratory animals of the drug L-carnitine for veterinary use when administered subcutaneously, it was established that a dosage of 1/5 of the maximum tolerated, and a dosage of 1/10 of the maximum tolerated, does not cause external signs of toxicosis and death in rats . No significant changes were found in the biochemical parameters of the blood of animals in the experimental and control groups. 

Currently, the healthcare system of the Russian Federation and veterinary legislation are undergoing a stage of systemic changes in order to meet modern requirements and fulfill the tasks assigned to it.
More than 100 new medicines are registered every year, and the demand for veterinary services in large cities is increasing. There is a need to find the optimal therapy at the lowest price. Pharmacoeconomics offers various methods that help select the best treatment option that is the most cost-effective. This contributes to capacity building as it helps optimize the resources needed by organizations and communities and various commissions to adapt and improve their capabilities.
The purpose of our study was to study the main indicators and existing methods for assessing the effectiveness of a drug from an economic point of view.
The main methods adopted in different countries and validated are QALY, EuroQoL group questionnaire.
Thus, in medical articles, such indicators as Cost-utility analysis, Willingness-to-pay threshold, Budget impact analysis are often found. Our recommended set of guidelines can become the basis for further discussion and help determine the final set for official inclusion in the Russian regulatory framework for assessing the use of pharmacological agents in veterinary medicine. This recommendation will be useful both for the manufacturers themselves, and for experts who are members of the authorities that control pharmaceutical turnover in the Russian Federation. Which in the future will serve as the foundation for creating a common basis for the EAEU countries in the system of circulation of medicines in veterinary practice.

Feeding hygiene in beekeeping solves the problems of the quantity and quality of feed, increasing its usefulness, as well as monitoring the quality of feed and feed base. Providing bee colonies with a sufficient amount of carbohydrate feed of proper quality is an important component of beekeeping technology, especially in the natural and climatic conditions of the middle taiga subzone, where the honey bee (Apis mellifera) is located on the edge of the natural habitat. Noncompliance with food hygiene in such conditions dramatically reduces the adaptive capabilities of the bee organism, and can be considered as the main reason for reducing the resistance of the organism of beneficial insects. In the article, the authors touched upon the problems of hygiene of carbohydrate nutrition of honey bees, showed the possibility and real implementation of the implementation of a full-fledged carbohydrate diet in the conditions of the North-West of Russia. Carbohydrate feeds and nutrition are considered by the authors as factors determining the normal functioning of all systems of the bee organism and a means of preventing feed toxicosis.

In the system of sanitary, anti-epidemic and anti-epizootic measures that ensure the well-being of the country in terms of infectious diseases, increasing animal productivity and the sanitary quality of products, raw materials and feed of animal origin, disinfection occupies one of the important places. Disinfection is understood as the destruction of objects or the removal from them of pathogenic and conditionally pathogenic microorganisms. The main purpose of disinfection is to break the epizootic chain by influencing its important link - the factor of transmission of the pathogen from the source of infection to the susceptible organism. Given the variety of existing disinfectants and their constituent components, preparations with high bacterio- and virusstatic activity are very limited, which does not allow effective disinfection of contaminated surfaces, especially those contaminated with organic substances. The problem of introducing new highly effective disinfectants has become particularly relevant in connection with the spread of highly pathogenic microorganisms throughout the country.

This study draws attention to the current problem of pollution of aquatic ecosystems with microplastics and its potential impact on humans through food products. The level of microplastics in smelt Osmerus eperlanus, caught from the Neva River in St. Petersburg, was assessed. The research methodology included collecting fish samples and examining their internal organs and muscle fibers for the presence of microplastics. The results showed that microplastic particles were present in all samples examined, especially in female smelt. The study also found the presence of microplastics in the muscles of the fish, indicating the possibility of their entry into the human body through fish consumption.

The work examines the results obtained when feeding feed additives to quail. A preparation containing the bacteria Bacillus subtilis was used as a feed additive for the birds of the first experimental group; feed yeast was introduced into the diet of the experimental group; all birds received supplements starting from the first day of life. In the control group, the birds were given only the basic diet, represented by an industrial combined feed for quail, in accordance with their age. Control weighing of birds in the experimental and control groups was carried out on the 28th, 42nd and 56th days. Blood was also obtained from the axillary vein for its biochemical study. As a result of the work, it was determined that when feed additives were introduced into the diet of quails, growth and development indicators increased, namely, in the first 42 days of the experiment, there was an increase in the growth rate in the first experimental group of birds by 60.2%, in the second experimental group by 56.8 , while the growth rate of quails in the control group from the first day of the experiment was 55%. By the 56th day of the experiment, the growth of the birds had slowed down significantly and no significant differences in the dynamics of this indicator were observed. During a biochemical study of blood obtained on the 56th day of the experiment, it was determined that the experimental birds had higher concentrations of total protein, an increase in ALT activity and a decrease in AST activity.

For the purpose of practical application of the method of determining the mass fraction of protein according to Barnstein for various one-component feed raw materials of animal and vegetable origin, we conducted a series of experiments on four types of raw materials: fish meal, meat and bone meal, corn gluten, sunflower cake. To do this, each sample of feed was divided into 2 samples and an additive was introduced into each (one additive contained protein, and the other non– protein nitrogen). Determination of the protein nitrogen content in feed was carried out under the same conditions as the analysis of the initial samples. When comparing the theoretically calculated value and the practical result for all types of feed samples, reliable results were obtained. The conducted studies have shown the need to control raw materials to establish the true protein content in order to exclude the possibility of contamination with nitrogen-containing substances of non -protein origin.

Currently, the problem of processing various types of organic waste from agricultural and food production is becoming more pressing, since they most often have to be disposed of by paying for this service. At the same time, the cost of protein components and, as a consequence, feed is constantly increasing.
The development of new technologies and technical solutions is becoming relevant.
One of these technologies, which makes it possible to produce feed products for fattening animals, is the biothermal processing of organic waste using special installations.
Technological solutions used in ECO biocomposters made it possible to create a completely autonomous machine for processing food and organic waste of various volumes.
In our article we publish the results of a chemical analysis of the resulting compost after processing plant waste - vegetables and root crops - for compliance with certain indicators of GOST 9268-2015 (concentrated feed for cattle).
The studies carried out established compliance with GOST for a number of indicators: the mass fraction of crude fat, crude protein, soluble carbohydrates, phosphorus and nitrogen was normal. An increased content of moisture and crude fiber was observed, which is associated with the composition of the starting material and the features of the technology.

The relationship between the height of filling of test tubes with blood and quantitative indicators of platelet plasma obtained by centrifugation was studied on blood samples of Wistar rats. The test tube filling height of 6.0 cm and 3.0 cm was chosen as the comparison criteria. In combination with another criterion, such as the volume of blood placed in a test tube, a total of four (4) variants of platelet plasma production were investigated and analyzed. In the first variant (No. 1), the tubes contained 4.0 ml of blood, the height of filling the tubes was 6.0 cm. In the second variant (No. 2), the tubes contained 2.0 ml of blood, the filling height of the tubes was 3.0 cm. In the third variant (No. 3), insulin syringes were used, which contained 1.0 ml of blood, their filling height was 6.0 cm. In the fourth variant (No. 4), insulin syringes were also used, which contained 0.5 ml of blood, their filling height was 3.0 cm. All test tubes/syringes were centrifuged in the same mode (3000 rpm – 1.0 min + 1000 rpm – 10.0 min) on an OPN-3 centrifuge with a bucket rotor. Further, the concentration of platelets in the separated plasma was immediately determined at different distances from the upper layer of the erythrocyte sediment. Then the plasma was completely sampled, the platelet concentration and its volume were determined.
The results were processed by methods of variational statistics. Analysis of the results showed that in variants No. 1 and No. 3, the concentration of platelets in the resulting plasma was almost 30% and 10% higher than in variants No. 2 and No. 4, respectively. Considering that the total amount of plasma obtained, expressed as a percentage relative to the initial amount of blood, was approximately the same in all variants, it can be concluded that a higher level of filling of test tubes with blood before centrifugation makes it possible to obtain plasma more saturated with platelets.

This article presents the results of a comparison of the activity of indicator enzymes of the hepatobiliary system in horses - alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) with the activity of gamma-glutamyltransferase (GGT). The results of a biochemical blood test were grouped according to the activity of gamma-glutamyltransferase and, in connection with this, 4 groups were formed with an enzyme activity step of 10 IU/l. When conducting a correlation analysis, a strong positive relationship was revealed between the level of GGT and AST (r = 0.97) and ALP (r = 0.88), and when comparing GGT and ALT, a moderate positive relationship was found (r = 0.64). The absence of natural changes in ALT activity with increasing GGT is explained by the induction of the enzyme to ensure the optimal rate of transamination in metabolic reactions, and not a consequence of liver pathology. A statistically significant increase in AST and ALP activity was found in the group with GGT activity exceeding standard limits, compared with the minimum values by 59.1% and 29.7%, respectively (P<0.05). An increase in GGT activity above the upper limit of the reference limits is accompanied by a significant increase in aspartate aminotransferase and alkaline phosphatase levels, which indicates the presence of pathology of the hepatobiliary system involving both the liver parenchyma and the biliary tract.

The taste organs have a species-specific structure in different animal species. The development of the taste bud in different species of fish occurs at different periods of ontogenesis. The purpose of our work was to study the morphological features of the structure of the taste bud in Clarias gariepinus.
Analysis of our studies made it possible to determine the histological features of the structure of the mucous membrane of the esophageal wall. The taste bud is an important structure in the digestive system of the African clary catfish. It is round in shape and consists of specialized cells that have a number of features, each of which has a specific function. In the region of the taste pore at the apical pole, neurosensory cells are equipped with cilia, through which the signal is transmitted to the afferent nerve fiber.
The data obtained can be used to study the microstructure of Clarias gariepinus organs, as well as to determine taste preferences, which will allow optimizing the operation of enterprises producing feed and therapeutic and prophylactic drugs for these fish species.

The nervous system is one of the leading integrating systems of the body. In combination with the cardiovascular and endocrine systems, it unites the body into a single whole. The nervous system controls the level of adaptive reactions of a living organism to changing environmental conditions. The Nile bat (Rousettus aegyptiacus) is a typical representative of the order bats. The purpose of our study is to study the macromorphology of individual anatomical structures of the brain of the Nile bat (Rousettus aegyptiacus). The material for the study was four different-sex animals of the Nile bat species (Rousettus aegyptiacus) aged 10-14 years, obtained from private veterinary clinics. The methods for studying the brain of the Nile bat were: fine anatomical dissection, morphometry, photographing, weighing. The work was performed on the basis of the Department of Animal Anatomy of the St. Petersburg State University of Veterinary Medicine. As a result of the study, it was found that due to the strong development and large size of the auditory posterior tubercles of the quadrilateral, it is possible to judge the predominance of the auditory analyzer, while the anterior tubercles of the quadrilateral have a relatively small size, most of the structures of the visual analyzer are contained in the neocortex. It was found that there is no division of the cerebellar fragment into anatomical structures in the brain, and the size of the flocculonodular lobe of the cerebellum in this species is on average 1.30x1.10±0.15x0.10 mm. The absence of pronounced lobes and furrows was revealed, and the Nile bat (Rousettus aegyptiacus) belongs to lysencephalic animals. The obtained materials can be used as a reference material for continuing research on the brain of the Nile bat (Rousettus aegyptiacus), as well as in comparative morphology and physiology of humans and animals.

Modern industrial pig farming involves the intensification of production and the search of methods to reduce costs in the production of pork, observing veterinary and sanitary requirements. All this is aimed at solving the issue of food security of the country and solving the issue of import substitution. Nevertheless, the intensification of pig farming is accompanied by a violation of the physiological needs of the animal's body, as well as a decrease in its resistance and exacerbation of existing diseases. A healthy metabolism in the body of lactating sows lays the foundation for the further health and productivity of her offspring.
The purpose of the study was to assess the effect of different doses of the «LikvaFid» supplemental nutrition complex on the biochemical parameters of the blood of sows during lactation. During the experiment, biochemical parameters were analyzed: total protein, albumins, globulins, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, urea, total cholesterol, triglycerides, calcium, phosphorus, magnesium, iron, zinc and copper. To conduct the experiment, 4 groups of analogues were formed from sows with a history of 2 to 5 farrowing. The first experimental group (n = 10) of sows received the probiotic additive «LikvaFid» at a dose of 40 g, the second (n = 10) – 50 g and the third (n = 10) – 60 g per 1 ton of consumed water. The animals of the intact group (n=10) did not receive a probiotic supplement. Blood sampling from all sows was performed once from the jugular vein before weaning the young.
According to the results of the study, it was found that the use of different doses of the probiotic complex «LikvaFid» to sows during lactation has a beneficial effect on the biochemical parameters of blood serum. The studied indicators characterizing protein and lipid metabolism mainly did not go beyond the reference values, which indicates the physiological course of metabolic processes in the body of sows. Against the background of the use of «LikvaFid», hepatocellular metabolism is normalized and the concentration of vital micro- and macronutrients increases. Positive changes in the biochemical composition of sow blood are associated with normalization of the intestinal microbiome and improved absorption of nutrients throughout the gastrointestinal tract.

Alimentary osteodystrophy occurs as a result of an unbalanced diet, which leads to a violation of metabolic processes, one of which is protein metabolism. The purpose of this study was to analyze the main indicators of protein metabolism, such as total protein, α - globulins, β - globulins, γ - globulins, as well as to determine the concentration of glycoproteins and sialic acids in highly productive cows with alimentary osteodystrophy.
The research was carried out on the basis of a livestock complex in the Leningrad region and at the Department of Biochemistry and Physiology of the FSUE HE "SPbGUVM". To conduct the experiment, two groups of animals were formed using the method of pairs of analogues. The first control group consisted of clinically healthy animals in the amount of 15 heads. In the second - experimental group, animals with alimentary osteodystrophy in the amount of 15 heads. Blood was taken from cows from the tail vein into vacuum tubes. Before taking blood, clinical examination and thermometry of animals were performed.
When analyzing the data obtained, a tendency was revealed to decrease the concentration of total protein in the group of sick animals, there was a decrease in albumins (significantly lower (p<0.05) by 1.8 times) compared with the group of healthy cows, as well as a significant increase in the blood content of alpha-globulins in the blood of sick cows by 2.4 times compared with healthy ones. The content of glycoproteins in sick animals was 1.8 times higher (p<0.05) than in healthy animals, the index of sialic acids was 3.4 times higher than in healthy cows (p<0.05). Thus, in the course of research, it was revealed that the state of alimentary osteodystrophy is accompanied by changes in the concentrations of indicators characterizing the protein metabolism of animals.
Thus, highly productive cows diagnosed with alimentary osteodystrophy are characterized by an increase in the blood of the α-globulin fraction of proteins, which includes proteins of the acute and chronic stages of inflammation, as well as glycoproteins and sialic acids, which are a marker of the degree of destructive processes in connective and cartilage tissue.

One of the indicators of behavioral activity in response to the impact of environmental factors is acoustic signaling as an element of sound communication of birds. The purpose of the research work was to study acoustic signaling of turkeys of Highbrid Converter cross, grown in conditions of poultry breeding enterprise of Tyumen region. The object of research were turkeys of different groups of different age (1, 12, 41, 56, 69 days) and sex. Loudness of sounds issued by the bird was measured by a noise meter, with fixation of maximum, minimum and average values of sound loudness. Audiometry was carried out in the morning and evening. 76 audiograms were recorded. In the course of background research it was noticed that turkeys constantly make sounds characteristic for the species, communicating among themselves birds do not stop shouting at night, and the noisiest are males. It was found that the average maximum values of loudness level of signals of birds in groups not divided by sex, in 41-day-old birds (81.3 dB) in the evening and in day-old chicks (71.6 dB) in the morning. In 41-day-old birds, the loudness level of acoustic signaling increases (by 5.2 dB) toward evening, and in dayold birds, loudness is 5.1 dB lower in the evening than in the morning. The amplitude of loudness increase has a sharp character. At the same time, the signal volume of day-old chicks in the morning has maximum values (82.0 dB), which are also found in the groups of older chicks (69 days). However, in the evening, the maximum values of day-old chicks' buzzer loudness decrease by 11.5 dB. In groups of chicks separated by sex at 56 days of age, the acoustic signals of males are louder (by 1.2 dB), both in the morning and in the evening (by 1.3 dB). It was also found that the loudness level in both the group of males (by 3.8 dB) and females (by 3.7 dB) increased towards evening. In the group of 69 day-old turkeys, female signals were 1 dB louder than male signals in the evening. Maximum loudness values were recorded in the male group (85.5 dB, 86.4 dB, 87.4 dB). 

This research was aimed at studying the effect of species-specific recombinant bovine interferon lambda (IFN-λ) on the generation of reactive oxygen species (ROS) in mouse liver and bone marrow cells under conditions of mitomycin Cinduced oxidative stress. The experiment included female white laboratory mice. There were formed four groups of 6 animals each: the negative control group (group I); the group of mice that received a three-fold injection of IFN-λ at a dose of 0.1 ml/kg (group II) and mice that, in addition to IFN-λ, were administered a cytotoxic drug that induced free radical oxidation processes - mitomycin C at a dose of 10 mg/kg (group III), as well as the animals receiving only mitomycin C (group IV). We studied the concentration and viability of a cell suspension obtained from the liver of mice, as well as the relative content of intracellular ROS in the liver and bone marrow cells of animals, assessed by the fluorescence intensity of the oxidized form of 2',7'-dichlorodihydrofluorescein diacetate. The concentration and viability of cells in the liver suspension of healthy mice did not change with the introduction of IFN-λ (group II), indicating the absence of a toxic effect of IFN-λ on these cells. An increase in the level of ROS in the studied cells was detected when IFN-λ was administered to mice of group II (an increase in the level of ROS by 1.3 times in liver cells and by 2.9 times in bone marrow cells, relative to the mice of group I) and a decrease in the level of ROS in the mice under conditions of oxidative stress induced by mitomycin C (reduction in the content of intracellular ROS by 1.9 and 7.2 times in liver and bone marrow cells in the animals of group III, relative to the mice of group IV). The presented changes may indicate the normalization of IFN-λ redox balance in the body and, probably, appear in connection with the immunomodulatory activity of IFN-λ.

In veterinary practice, hepatopathy in animals is quite common, the occurrence of which is preceded by either autoimmune damage by autoantigens or direct damage to the liver by various etiological factors. Such factors can be medications in the treatment and prevention of various invasive diseases, in case of erroneous dosage or in the individual reaction of the animal. The purpose of the work is to study in a model experiment the effect of a toxic drug (carbon tetrachloride) on the functional activity of hepatocytes in rats. The work shows that the toxic effect of carbon tetrachloride is manifested by a pronounced clinical picture of liver damage and changes in transaminase activity. The changes have a cascade character - at the first contact of the toxicant with hepatocytes, damage to the cell membrane and activation of ALT occurs; subsequently, an increase in the activity of AST and ALТ is observed, indicating systemic disorders, first of the liver, and then of the heart muscle.

The purpose of the study is to determine the validity of culling of pigs with morphological changes that occur when stunned before slaughter by carbon dioxide, according to Veterinary Rules of animal slaughter No. 68718 02.06.2022. As the research material, lung samples of 8 healthy slaughter pigs aged 6.5-7.5 months, weighing 95-105 kg, including 3 pigs stunned by electric shock, and from 5 pigs that were stunned by carbon dioxide were used. The samples were fixed in a 10% solution of neutral formalin. Histological sections were made, they were stained with hematoxylin and eosin. In the lungs of 3 pigs, which were stunned with electric shock and then exsanguinated, during post-slaughter examination, a uniform staining of the organ in light red color, elastic consistency was established, which corresponded to a normal lung. In the lungs of 5 pigs, which were stunned with carbon dioxide and then exsanguinated, heterogeneous staining was established during post-slaughter examination; there were areas of dark red color and compacted consistency, frothy liquid was released from the surface of the incision. In histological preparations of the lungs of pigs that were stunned with carbon dioxide, edema of the alveoli and congestive hyperemia of blood vessels were detected, which should be recognized as the result of insufficient exsanguination. In histological preparations of the lungs of pigs, which were stunned with electric shock, fullness of blood vessels and pulmonary alveolar edema were found. The rules of veterinary and sanitary examination do not indicate the culling of lungs with hyperemia and edema, that is, they are not subject to disposal and destruction. Assuming the exact execution of directive documents and careful treatment of animal slaughter products, it makes sense to officially recognize such lungs as either subject to destruction or suitable for a certain use.

According to the literature, sensitive digestion in dogs is quite common. About 25% of visits to veterinary clinics are related to diseases of the gastrointestinal tract. Sensitive digestion is a feature of the gastrointestinal tract associated with the body’s intolerance to any substances. As a rule, this condition is accompanied by disruption of enzymatic processes in the gastrointestinal tract, deterioration of absorption in the intestine and diarrhea.
A clinical blood test allows you to evaluate the number and morphology of red blood cells, the concentration of hemoglobin in the blood, the hematocrit value and a number of red blood cell indices that reflect the physical characteristics of red blood cells. With a comprehensive assessment, these indicators give an idea of the presence or absence of anemia and dehydration, and also allow one to assess the degree of their severity.
Changes in red blood levels during sensitive digestion are usually explained by a lack of vitamins and microelements, which develops as a result of decreased digestibility of food, as well as losses of fluid and nutrients as a result of diarrhea.
In this article, red blood parameters in a group of dogs with sensitive digestion are assessed using standard hematological testing techniques to obtain baseline data and compare these indicators with the results that will be obtained after correcting the condition of the gastrointestinal tract with specially designed therapeutic diets.

The Eurasian lynx is widely popular among wild feline animals. It is often the object of domestication and it is bred on fur farms for the extraction of fur products. Heart vascularization in domestic and wild mammalian animals has not been studied enough and is still an urgent area of research, our goal was to study the anatomy of the left coronary artery of the Eurasian lynx heart and establish its anatomical and topographic patterns. To study the anatomy of the heart, the corpses of the Eurasian lynx were taken at the age of two or three years. In total, five corpses of the Eurasian lynx were examined. Cadaver material was delivered from private fur farms of the Leningrad and Moscow regions to the Department of Animal Anatomy of the St. Petersburg State University of Veterinary Medicine. To study the vascularization of the heart of the studied animals, classical and modern anatomical techniques were carried out, such as fine anatomical dissection and the manufacture of corrosive preparations using latex. According to the results of the study, it was found that the left coronary artery in the Eurasian lynx is sufficiently developed and supplies blood to the structures of the left and right half of the heart, and the subsinuous artery does not belong to the branches of the left coronary artery, in connection with which it can be concluded that the uniform type of blood supply in the Eurasian lynx. The results of the study can be used by veterinary specialists, in particular surgeons, to establish operative access to the heart in the form of a pattern of branching of the left coronary artery of the heart in the Eurasian lynx.

The aim of the study is to assess the impact of prolonged irregular search and rescue operations on the biochemical blood parameters of medium–breed service dogs.
The study was conducted on dogs of medium breeds: Border Collie, Australian Shepherd, Nova Scotia Retriever. The age of the studied animals ranged from four to ten years, and the body weight from 16.2 to 22.0 kg. Assessment of the condition of animals before and after their participation in search and rescue operations was carried out based on the results of clinical examination and biochemical blood analysis. Biochemical blood analysis was performed on a Stat Fax 4500 analyzer. The following parameters were determined: calcium, phosphorus, potassium, sodium, chlorides, magnesium, urea, creatinine, ALT, AST, alkaline phosphatase, total protein, albumin, globulin. Glucometry was performed at the beginning of the study. Blood sampling was carried out from the peripheral vessels of the ear using scarifiers. Most dogs received treats and were not hungry, which was taken into account when interpreting the results. A CareSens N glucose meter was used to measure blood glucose levels. Based on the data obtained, no signs of any diseases were detected during the physical examination, all animals were clinically healthy. However, the occurrence of obvious stress was noted in all animals. Blood sampling for biochemical analysis was carried out after at least eight hours of a starvation diet, from the lateral subcutaneous vein of the thoracic limb, taking into account compliance with the rules of asepsis and antiseptics.
It was found that the loads during prolonged irregular search and rescue operations have an impact on the biochemical picture of the blood, expressed in a decrease in the average value of phosphorus, total protein, globulin, as well as in an increase in the average value of calcium, potassium, sodium, chlorides, magnesium, urea, creatinine, ALT, AST, alkaline phosphotase, albumin, glucose.

Relevance. The skin of cattle consists of the epidermis and dermis. The dermis, or the skin itself, in turn consists of papillary and mesh layers. However, in the literature we have not found studies on the morphometry of different topographic areas of the skin of cattle. The aim of the study is to conduct comparative morphometric studies of the skin of various topographic zones in adult cows.

Methods. For morphometric studies, histological preparations prepared according to the generally accepted method from skin samples of different topographic areas in adult cows were used. The research was carried out at the of the St. Petersburg State University of Veterinary Medicine Department of Pathological Anatomy and Forensic Veterinary Medicine and at the Department of Biology, Ecology and Histology. Morphometric studies of histological preparations were used to study the thickness of the dermis proper, as well as bundles of collagen fibers of the mesh layer of the dermis. The results of the studies were processed using the "Biostat" program.

Results. Morphological features of the skin of different topographic areas in adult cows have been established, which are manifested by differences in the thickness of the skin layers and bundles of collagen fibers of the dermis. The morphometry performed allows us to expand the data on the morphological structure of the skin of adult cows.