The article analyzes the powers of the Federal Service for Veterinary and Phytosanitary Surveillance to carry out federal state control (supervision) in the field of circulation of medicines for veterinary use, and also highlights the issues of assigning controlled objects to certain categories of risk of harm (damage) to legally protected values, which determines the range of preventive and control measures and their scope.

The updated regulatory framework in the field of circulation of medicines has been studied, data on the number of controlled facilities in the north-western interregional Rosselkhoznadzor administration in accordance with the assigned risk category, which is necessary to prevent emerging violations and to eliminate them in a timely manner, as well as data on the analysis of these indicators.

The article presents an analysis of the current legislation of the Russian Federation, the requirements of which must be observed by enterprises engaged in the disposal and incineration of organic waste, including biological waste.

Taking into account the diverse requirements of the current legislation, enterprises engaged in these activities need to be guided by the requirements of veterinary legislation, environmental and sanitary-hygienic.

It is also worth noting that in the Russian Federation there is practically no or very little infrastructure necessary for the full utilization of organic waste [1].

Modern livestock breeding technologies imply the maximum use of the productive potential of animals. Animal diseases of various etiologies are a significant obstacle to the fulfillment of this task, causing significant economic damage, consisting of a shortage of products, restrictions on its sale and treatment costs. One such disease is genital mycoplasmosis in cattle. The aim of our research was to study the effect of treatment of genital mycoplasmosis in cows with tulathromycin on some indicators of nonspecific resistance. Studies were carried out on two groups of pregnant cows, a group of animals with mycoplasmosis was treated with tulathromycin, healthy cows served as controls. In both groups of animals, the activity of lysozyme, bactericidal activity of blood serum, phagocytic activity and phagocytic index were determined. It has been established that the use of tulathromycin leads to the recovery of 75% of infected cows, and also leads to an increase in phagocytosis, which does not significantly differ from the level of healthy animals. To a lesser extent, the use of this drug in genital mycoplasmosis affects the bactericidal and lysozyme activity of blood serum.

Microorganisms resistant to antimicrobials pose a worldwide threat to humans and animals and are of interest to bacteriologists. Antibiotic resistance of E. coli is being studied all over the world as one of the most resistant and, as a result, dangerous types of microorganisms. Due to the enzyme complex (extended spectrum beta-lactamase) produced by the bacterial cell, E. coli hydrolyzes beta-lactam antibiotics, including third and fourth generation cephalosporins, which makes research in this area extremely relevant.

The aim of our study is to analyze the literature data on the distribution of enterobacteria producing beta-lactamase among cattle.

Analysis of published data with the results of studies of isolates obtained from cattle farms in Russia, Europe, Asia and Africa confirms the widespread distribution of beta-lactamase strains of E. coli.

The study of their phenotypic and genotypic features using MICs followed by genomic sequencing by scientific groups from different countries makes it possible to identify resistance genes in isolated E. coli and compile statistics on the occurrence of specific genes responsible for bacterial resistance.

Given the data obtained, it is possible to draw logical conclusions about the increase in the number of resistant pathogens on farms around the world, which is primarily due to the widespread use of antimicrobials at all stages of growing farm animals; about the danger posed by such strains; about the need to take measures to prevent the spread of resistant microorganisms by changing the principles of prevention and treatment of infectious diseases of farm animals.

Monitoring of the incidence of cats and dogs with infectious diseases, as well as the development of recommendations to owners to prevent infection of their pets with these diseases, are important elements of ensuring the epizootic well-being of cities. It was found that cats are more susceptible to infection with infectious diseases, for 2019-2021, the Veterinarian Advisory Center annually received 111 cats and 17 dogs with infectious pathology on average. The most frequently reported pathologies are calico- and herpesvirus infections of cats. There is no clearly predominant infectious pathology in dogs. A single dynamics of the incidence of infectious diseases in animals by year has not been revealed. When analyzing treatment regimens and preventive measures for infectious diseases of cats and dogs, we come to the conclusion that if there are effective means of complex therapy, animal owners need to focus their attention on their specific prevention with the use of Russian vaccines.

Obtaining healthy offspring with good productive qualities is an urgent task in the conditions of modern animal husbandry. Any diseases of pregnant animals affect the fetus to varying degrees. In this regard, of particular interest is the study of the state of cellular immunity of calves in the presence of genital mycoplasmosis in their mothers. Studies were carried out on 7–9-day old calves obtained from cows with genital mycoplasmosis and healthy cows. The presence of genital mycoplasmosis was confirmed by a PCR test for Mycoplasma spp., followed by serological identification of M. bovigenitalium. In calves, the absolute content of lymphocytes, the relative and absolute content of T- and B-lymphocytes were determined. The results of the study show that genital mycoplasmosis in mother cows leads to a deficiency of cellular immunity in their calves, which is manifested by a significant decrease in both the absolute and relative content of lymphocytes, as well as an imbalance in their subpopulations.

The aim of the work is to carry out bacteriological methods of isolation of enterobacteria from the feces of the maize fly and their identification.

Fecal masses were selected after molting from a male maize runner named Rabbit morphs Bloodred het Pied-Sided (Fig.1). Date of release from the egg: 06/19/2020.

The primary sowing of "tampon-loop" was carried out on chocolate agar and Endo medium. The final identification was carried out by the RapID ONE System test system (Thermo Fisher Scientific, USA).

As a result of the work, morphological properties were studied: gram-negative rods collected in groups or arranged singly, the presence of a capsule was established.

Isolated E.coli cleaved lactose, sugar aldehyde, glucose, mannitol, sorbitol, rhamnose, melibiose and arabinose, possessed enzymes lysine decarboxylase, ornithine decarboxylase, γ-glutamyltranspeptidase, reacted with aliphatic thiol.

Representatives of the genus Kocuria are found in soil, marine sediments, water, on the skin and oropharynx of mammals. This paper presents the results of a study to determine the biological properties of Kocuria sp. isolated from goat milk. There is evidence of association of opportunistic Kocuria spp. with the development of severe septic conditions, meningitis, endocarditis, cholecystitis, and osteomyelitis.

This paper presents several clinical cases of pathology of the urinary system - nephrolithiasis, special attention is paid to ultrasound diagnostics in the study of the pathogenesis of this disease. It has been established that with the help of ultrasound diagnostics it becomes possible to track the dynamics of pathological changes occurring in the organ, which makes it possible to increase the effectiveness of therapy. 

The paper presents the results of a morphological study of the blood of healthy dogs and dogs with acute enterocolitis. Also, a physical examination was carried out on sick animals. On external examination, it was noted that the dogs with enterocolitis were mostly apathetic, some took a forced lying position. Of the studied 10 sick dogs, 7 had satisfactory fatness, 3 dogs had unsatisfactory fatness. In a significant part of dogs with enterocolitis, the coat is matte, the coat is ruffled and poorly retained in the hair follicles, the skin turgor is reduced. The color of the visible mucous membranes in dogs with enterocolitis varies from pale pink to grayish with an icteric tinge. The main revealed pathological changes in the study of the digestive system of dogs with enterocolitis were: increased defecation, diarrhea, feces of a mushy consistency with mucus admixtures, sometimes with blood, oligophagia or anorexia, abdominal wall tension, intestinal soreness with penetrating palpation, increased peristalsis with mediocre auscultation. In animals with signs of enterocolitis, erythrocytosis, leukocytosis and hyperchromemia were noted. At the same time, the hematocrit index was 20.9% higher in sick dogs, compared with this indicator in healthy animals. When analyzing the leukogram of animals of both groups, no significant changes were found.

A test system has been developed for the diagnosis of polycystic kidney disease in dogs, including primers, probes, and a stub oligonucleotide for another allele. A solution of a control plasmid with a wild-type gene fragment, with a fragment of the mutant allele of the gene, or a mixture of both, imitating a heterozygote, was used as a template. The system is based on the TaqMan method. This test system allows for early diagnosis of animals with mutant alleles in order to monitor the state of health during ontogenesis, as well as exclude these dogs from breeding before their puberty.

The article presents the results of hematological studies in aged cats with chronic renal insufficiency. The aim is to study changes in hematological parameters in aged cats with chronic renal failure and to evaluate the effectiveness of treatment in small veterinary clinics. The studies were performed on sick animals belonging to private owners (n=24). A total of 66 samples of blood and blood serum were examined. Clinical and hematological studies were carried out according to methods generally accepted in veterinary practice.

Unidirectional changes in the level of red blood indicators were revealed in aged cats, which is associated with the depletion of compensatory capabilities of the red bone marrow. In the blood serum of age-related patients, the content of nitrogenous products (total protein, urea, creatinine) was increased, indicating the fourth stage of renal dysfunction on the IRIS scale. Thus, in aged animals with chronic renal insufficiency syndrome, a decrease in the rate of hematopoiesis and glomerular filtration of the kidneys, a tendency to hepatopathy, osseopathy and changes in the elemental composition of the internal environment of the body were established. The treatment was carried out with the transfer to the Renal series feed and the improvement of the drinking regime

Etiotropic therapy included oral administration of sinulox at the rate of 12.5 mg / kg of body weight, twice a day, for 5- 7 days. Substitution treatment included intravenous administration of saline solution. Symptomatic treatment consisted of intramuscular administration of pyridoxine and cyancobalamin, oral use of the drug "bio-iron" in courses of 10 procedures.

Two patients died. The 15 out of 22 cats showed an improvement in clinical indicators and an increase in body weight. The use of treatment of age-related patients with symptoms of stage IV chronic renal failure for 10 days allowed to stimulate appetite, improve diuresis and thirst, stop inflammatory processes in the body and support hematopoiesis, reduce the level of nitrogen-containing metabolites. But it is impossible to achieve a complete restoration of the functional activity of all organs.

The main methods of diagnosing these diseases, according to the analysis of world literature data, are the analysis of the patient's cerebrospinal fluid and magnetic resonance imaging (MRI). The analysis of cerebrospinal fluid (CSF) is carried out in order to detect changes characteristic of the diagnosis. With the help of MRI, it is possible to determine the localization of inflammation. A number of studies have been aimed at improving diagnostic methods by detecting new factors characteristic of autoimmune diseases of the nervous system. Data on the detection of antibodies corresponding to human antibodies in the cerebrospinal fluid of dogs and on changes in the concentration of various substances in it are presented. This allows for faster and more accurate diagnostics.

As a result of the generalization of the literature data, it was found that immunosuppressive drugs are used for the treatment of autoimmune diseases of the brain and spinal cord of dogs. According to the data presented, the most effective of the known methods of treatment of autoimmune meningoencephalitis is the use of a combination of prednisolone and imatinib mesylate. For the treatment of steroid-dependent meningoarteritis (SRMA), various corticosteroid drugs are used, the most optimal of which is the combination of prednisone and cytarabine.

The purpose of our study was to study modern Russian and foreign literature sources on autoimmune diseases of the brain and spinal cord in dogs, methods of diagnosis and treatment of these diseases and to review works that provide new data on their treatment, diagnosis and understanding of etiology and pathogenesis.

In modern veterinary practice, there is an acute problem of restoring the structure and function of damaged articular cartilage in animals, especially in one-hoofed animals. Cartilage tissue has a limited ability to regenerate due to the fact that it does not have blood and lymphatic vessels. With large defects, fibrous tissue or fibrous cartilage grows, which differ from hyaline cartilage in biochemical and biomechanical parameters. Subsequently, the cartilage undergoes degeneration, which in some cases may progress to osteoarthritic changes. Numerous studies have been conducted in the last few years in search of effective treatments. Among them is the use of mesenchymal stem cells (MSCs).

The purpose of this work was to review the results of studies presented in the current literature on the topic of articular cartilage regeneration using mesenchymal stem cells.

The search for original studies was carried out in the systems ResearchGate, PubMed, Liebertpub. Information about the properties of mesenchymal stem cells and the features of their use, the results of clinical studies, as well as the degree of knowledge and future prospects are given.

MSCs have the ability to self-maintain and differentiate into various mesenchymal cell lines (osteoid, chondrogenic, adipogenic). They are involved in the growth and development, restoration and regeneration of mesenchymal tissues. Based on the properties of MSCs, they represent a potential source of cells to induce regeneration of the affected articular cartilage.

Currently, MSC-based therapy is still in preclinical and 1 stage of research. Large-scale clinical trials are required to comprehensively assess the mechanism of action of MSCs, and subsequently address issues of its improvement.

A car accident is a type of injury that a patient receives as a result of a collision with a vehicle. This type of injury is a frequent occurrence in clinical practice, but despite this, careful monitoring of the condition of the wounds, the general condition of the patient, compliance with the rules of asepsis and antisepsis, and knowledge of how to use certain dressings is required. Dressings, with their proper use, contribute to the fastest possible healing of wounds without complications. The purpose of the study was to research the effect of various dressings on the wound surface in patients with scalped wounds. The object of the study was 10 animals with car injuries. The studies were carried out on the basis of the veterinary clinic of Dr. Sotnikov, in the intensive care unit. Evaluation of the nature of wound healing was carried out using daily visual examination, assessment of exudate from the wound, daily assessment of blood tests.

Dental disease is common in domestic rabbits. It manifests itself in a variety of clinical signs and can contribute to the development of rhinosinusitis and dacryocystitis. By itself, dental disease prevents the animal from eating normally, which contributes to the development of diseases of the gastrointestinal tract, exhaustion and death of animals. Over the past few centuries, rabbits have become widespread as pets, which has rather led to an increase in the popularity of dwarf rabbits. At the same time, in addition to the small size of the body, some brachycephaly of the head is observed in dwarf rabbits: shortening of the facial skull relative to the size of the body and brain skull. A number of authors argue that such morphological changes lead to an increased risk of developing dental disease and associated pathologies (dacryocystitis and rhinosinusitis).

Obstetric and gynecological diseases in cows, including endometritis, are one of the main obstetric and gynecological problems in animal husbandry. To date, the incidence rate of cows with endometritis of various etiologies is quite high and amounts to 37.5%. The arsenal of drugs used in veterinary obstetrics, gynecology, andrology and reproductive technologies is constantly growing and expanding. In recent decades, new veterinary drugs have appeared on the drug market, which are used in clinical practice to regulate reproductive function and for therapeutic purposes in domestic and wild animals. When analyzing registered veterinary drugs against animal endometritis, it showed that most of them are domestic drugs (83%), and the rest are foreign (17%). Of all drugs, the group of antibacterial drugs accounts for 44.4%: 25% of which can be attributed to the group of macrolides; 25% of the group of quinolones and fluoroquinolones; 12.5% belongs to the group of cephalosporins; 12.5% belongs to the tetracycline group; 12.5% refers to the group of aminoglycosides in combinations; 6.25% belongs to the group of penicillins; 6.25% other antibacterial drugs. A less extensive group of drugs against endometritis are antiseptic - 22.2%. Of these, 37.5% are based on iodine. Antihypoxants and antioxidants, vitamins and vitaminlike substances account for 5.6% of the total number of medicines. 22.2% includes drugs of different pharmacological groups. When analyzing the dosage forms used in the treatment of endometritis in cows, the following results were obtained: the share of liquid dosage forms for intrauterine administration accounted for 44.5%, liquid dosage forms for parenteral use 30.6%, solid dosage forms accounted for 11.1%, soft dosage forms 13.8%. A large group of drugs for the treatment of endometritis are antibacterial drugs, the choice of which is quite justified.

Pharmacokinetic modeling is a mathematical representation of the behavior of a pharmaceutical substance in the presence or anatomical and topographical area, created to describe pharmacological or refined kinetic characteristics. Pharmacokinetics is the science of basic processes observed over time and approaching the action of clinical manifestations. These nutritional patterns model biological processes, refer to the kinetic behavior of a drug after it has been introduced into the body, leading to a better understanding of its natural effects. Mathematical modeling is currently preferred, used in the study of research and biochemical systems. The spectrum of its use is from non-compartmental to large-scale multichamber models. In the case of compartmental models ("block model", "compartment model"), mass balance equations are used to represent each compartment. The number of compartments in the models depends on the rate of drug distribution over different topographic areas of the body. Most studies use one- or two-chamber models. When a substance is excreted from the body, its concentration in the systemic circulation and in all tissues decreases at the same rate due to the rapid distribution of distribution. This article is spent on the components of a one-component pharmacokinetic model specifically designed for various drug elimination models. The single-compartment open model is a simple way to describe the distribution and excretion of drug compounds from the body. This model assumes that drugs can enter or leave the body (an "open" model), and the whole body appears as a whole.

One of the urgent problems of aquatic toxicology is the increasing impact of heavy metals on hydrobionts. The aim of the study was to analyze the effect of high concentrations of lead acetate and copper acetate on carp gills during short-term exposure European carp (Cyprinus carpio carpio) was selected for the study weighing 1250 ± 136 g. During the experiment, 3 groups of 10 individuals were formed - a control group contained in water without a toxic agent; 1 experimental group of fish was contained in a solution of lead acetate (Pb(CH₃COO)₂) with a concentration of 0.6 mg/l (exceeding the maximum permissible concentration of lead for fishery reservoirs by 100 times); 2 the experimental group of fish was contained in a solution of copper acetate (Cu(CH₃COO)₂) with a concentration of 0.1 mg/l (exceeding the MPC of copper for fishery reservoirs by 100 times). The structure of the carp gill apparatus was studied by making a temporary wet preparation of the gill petals and its subsequent microscopy. The observed deviations in the state of the gills for the concentrations of copper and lead used included swelling and swelling of the gills, thickening of the epithelium, hypersecretion of the mucous cells of the gills.

There is growing evidence that micronutrient intake can lead to the development of poisoning and carcinogenesis caused by various chemicals. The article considers the question of the influence of the status of micronutrients on the toxicity of cadmium. After analyzing the literature data from both Russian and foreign databases (Scopus, Web of Science, RSCI), it was found that this topic on the effect of trace elements on the toxicity of heavy metals is relevant for scientists of various profiles.

Cadmium interacts with the metabolism of four metals necessary for a balanced diet: Zn, Fe, Ca, and Cu. As can be seen from the analysis of literature sources, one of the important aspects of cadmium metabolism is its interaction with the sulfhydryl protein metallothionein.

Like heavy metals, micronutrient availability in soil is affected by a number of factors. First, the availability of trace elements is directly or indirectly determined by the physicochemical and biological properties of the soil, such as pH, redox potential, soil organic matter content, complexing ligands, and underground biotic interactions. Based on the literature data, and analyzing the data obtained, it can be concluded that this issue remains relevant to this day. There have been few studies specifically designed to investigate the effect of micronutrient status on toxicity from non-essential metal exposure.

Thus, many factors other than diet can greatly influence the metabolism of toxicants in the body, and require further research.

One of the main problems of modern drug production is the assessment of bioequivalence during the life cycle of the product at the stage of preliminary approval (the stage of clinical trials) and at the stage after approval.

Getting a biowaiver is very important for pharmaceutical companies because of the significant savings in resources and time. However, if this is not done with scientific justification, safety and efficacy may be affected due to false positive decisions. Often differences in bioavailability are not found in pharmaceutical practice and hence are rarely reported.

A search of original studies in the scientific databases of PubMed, Elsevier Science (Scopus) and Clarivate Analytics (Web of Science) was carried out to determine the distinguishing features of the biowaiver methodology, followed by analysis of the data obtained.

In general, pharmaceutical development should relate in vitro dissolution to in vivo product efficacy. Under certain conditions, the results of a comparative bioavailability or clinical study can be extrapolated to all generic drugs. Biowaiver considerations include drug pharmacokinetics, dosage form type, manufacturing processes, and formulation proportionality. The article summarizes the unresolved issues associated with biowaiver based on the Biopharmaceutical Classification System (BCS), but also discusses the positive aspects of the prospect of further uses of the biowaiver procedure.

Unresolved issues that have arisen in the analysis of examples of false negative and false positive results described in the literature require further adjustment of regulatory requirements. Possible ways to solve these problems are the use of modeling and simulation, as well as the improvement of in vitro biorelevant tests, which are able to distinguish dosage forms with unequal in vivo efficiency, which potentially effectively allows the use of the biowaiver procedure.

The purpose of the studies was to study the cumulative properties of the drug Tildox. Tildox is a complex antibiotic in the form of a powder. One gram of antibiotic сontains as active ingredients doxycycline hyclate - 100 mg and tylosin tartrate - 100 mg and excipients.

The assessment of the cumulative properties of the drug Tildox was carried out on laboratory white rats males of the Wistar breed weighing 220-230 g. The rats were divided into 2 groups - experimental and control. There were 10 animals in each group. In the experimental group the drug was administered intragastrically once a day in accordance with the scheme in doses from 0.1 LD₅₀ to 1.12 LD₅₀.

The scheme of drug administration was as follows. From days 1 to 4 the dose was 350 mg/kg of doxycycline hyclate and tylosin tartrate; from 5 to 8 days - 525 mg / kg; from 9 to 12 days - 770 mg / kg; from 13 to 16 days - 1190 mg / kg; from 17 to 20 days - 1750 mg / kg; from 21 to 24 days - 2625 mg / kg; from 24 to 28 days - 3920 mg / kg. Control rats were injected with 0.9% sodium chloride solution in a volume of 2.0 ml. The duration of the experiment was 28 days.

As a result of the research it was found that LD₅₀ with repeated administration of the drug was 2659±183 mg/kg of animal weight. The cumulation coefficient was 0.76. Thus repeated parenteral administration of Tildox to rats leads to its accumulation in the body which causes a cumulative effect.

The most important side in breeding work is reproduction and its indicators. In modern conditions, domestic cattle breeds are losing their popularity, there is an intensive expansion of native breeds by Holstein bulls of American lines, which on the one hand leads to an increase in milk productivity, but at the same time leads to a decrease in the productive longevity of the livestock used. On the territory of the North-Western Federal District of the Russian Federation, mainly black-and-white root breeds are used, both locally selected, such as the Kholmogorskaya breed of cattle, the Yaroslavl breed, and "imported" ones.

The advantage of domestic cattle is that over the years, genotypically formed resistance to unfavorable paratypical factors has led to productive longevity, higher fertility rates than those of foreign-bred cattle used in the district. The young of native breeds have more advantages in terms of survival in the pre and postnatal periods of ontogenesis.

The study consisted in monitoring the realization of the reproduction potential among reproductive farms for the Kholmogorsky breed of cattle. The article presents materials on the monitoring carried out and their analysis is carried out, the indicators of reproduction on the territory of breeding farms are estimated. The analysis showed that the range of variability is about 10-15%, allowed us to draw conclusions about the need to control the quality of reproduction of young animals in livestock farms, confirmed the regularity (positive correlation) of live weight to the first insemination, as an indicator of growth and physiological development, created a number of recommendations for the zootechnical service of farms to improve the intensity of reproduction, increase the quality of the resulting repair livestock as a vector of improvement of the regional Kholmogorsky breed of cattle.

The nature of the Arctic creates unique conditions in which, in order to adapt and develop new cities, a person needs to take into account the experience of previously created northern economic regions. The article considers the main natural factors affecting the construction and urbanization of cities, assesses the prospects for the development of settlements beyond the Arctic Circle and analyzes environmental factors affecting the creation of a network of cities with a population engaged in oil-producing activities on a permanent basis.

To ensure the environmental safety of industrial solutions, it is necessary to purify wastewater from heavy metal ions, suspended particles and high-molecular decomposition products of the bio-mass during chemical and microbiological processes, while observing all the necessary conditions for local purification and recovery of industrial technical liquids. The purpose of the development of such a system is to control the process of wastewater treatment at all stages of its electrical reagent treatment. The objects of control were wastewater and natural waters in the process of purification by the electoreagent method, and ozonolysis was chosen as one of the most promising methods in this direction.

The aim of this study was to investigate the combined effects of thyme essential oil and Saccharomycetes on blood counts and body productivity in rainbow trout. The fishery complex demonstrates positive dynamics in all key economic indicators. The use of feed additives in a complete fish diet is one such practical solution that not only improves nutritional efficiency, but also helps to reduce stress and control diseases by strengthening the immune system of fish. The study was carried out in the fish farm of the Leningrad region, on rainbow trout. 3 groups were taken, 5 in each group. The control group received only the main diet, only Saccharomycetes were introduced to the diet of group 2, and thyme essential oil was added to the main diet of group 3 in addition to Saccharomycetes. The mixture was administered at a dose of 2% of the norm was the essential oil of thyme, and 0.1% of saccharomycetes. Physico-chemical indicators of water, including temperature, were at the same level in all groups, within the physiological norm. The experiment lasted 30 days; at the end of the experiment, blood was taken to study blood parameters. Statistical analysis was carried out using STATISTICA 6 software.

The present study showed that the combination of Saccharomycetes and thyme essential oil promotes the full development of fish and the efficient use of feed. Can theoretically successfully increase growth rates, survival rates, and digestive enzymes in farmed rainbow trout. Also, their inclusion in the diet can be useful for enhancing immune parameters and antioxidant responses and, therefore, can be included in the diet of this fish species as a safe feed additive.

Mineral metabolism in general and particularly electrolyte balance are integrated in all metabolic processes. The study of blood parameters deviations and ways of their correction in different animal species is an important and urgent task [1, 2]. Understanding the frequency of electrolyte disorders in dogs of small breeds, as the most common breeds of dogs of a large metropolis of St. Petersburg, will allow small pets veterinary specialists to prescribe additional studies competently and rationally, which in turn will improve the process of making the correct diagnosis and further treatment [5]. The purpose of the presented study was to identify the most common electrolyte disorders in dogs of small breeds (Yorkshire Terrier, Russian Toy Terriers and Pomeranian Spitz) in St. Petersburg with subsequent statistical processing of the results obtained. The object of the study was blood serum, in which the level of potassium, sodium, total calcium, ionized calcium, chlorides and phosphorus was determined according to generally accepted methods. The frequency of occurrence of electrolyte abnormalities in the group of old dogs (older than 12 years) was the highest (80%), electrolyte abnormalities were least common in adult dogs (from 1 to 6 years) (55%). In the group of aging dogs (from 7 to 11 years old), electrolyte disturbances occurred with a frequency of 72.73%. In 37.1% of all cases, two or more electrolyte level deviations were observed in all age groups. The most common violations of chloride levels were 40.32% (hypochloremia was observed in 1.61% of cases, hyperchloremia in 38.71% of cases). Violations of serum sodium levels were the least frequent – 3.23% (hyponatremia was not observed, hypernatremia was observed in 3.23% of cases). It should be noted that in order to more accurately determine the diagnostic significance and the possibility of determining forecasts, it is necessary to increase the number of animal samples with an assessment of indicators in dynamics.

Fasting (short or long term) is an important factor influencing physiological changes in immunity, survival and growth. During starvation, the most important processes in fish are supported by the accumulated nutrients. Structural components of the gastrointestinal tract and associated organs respond differently to food deprivation. We found that fasting had a profound effect on intestinal histology, which ultimately led to malabsorption and transport. In particular, there was hyperplasia of goblet cells, a decrease in the height of prismatic epitheliocytes with degeneration of microvilli on their apical surface. In some situations, fusion of the intestinal folds was detected. It should be noted that this issue has been poorly studied in the available domestic literature.

To date, many studies have been conducted on vascular vascularization of the colon in mammals, but few of them concerned the features of the course and branching of vessels, in particular intramural veins with possible surgical interventions on omnivores. In connection with the above about the relevance of rectal research, we set a goal to study venous vascularization of the rectum, and use Yorkshire piglets as a model. Cadaverous material for the study was delivered to the Department of Animal Anatomy of the St. Petersburg State University of Veterinary Medicine from the Idavang Agro pig breeding complex in Nurma village, Tosnensky district of the Leningrad Region. The study was conducted according to the third stage of development – the second dairy (22-45 days of the postnatal period), according to the periodization of the life of pigs. To achieve this task, a complex of traditional anatomical research methods was used: fine anatomical dissection, vasorentgenographic, photographing and morphometry. When examining the rectum of Yorkshire piglets, it was found that the main venous highway of this organ is the cranial rectal vein, as well as the presence of a wide network of anastomoses of the pelvic cavity organs should be taken into account when it is possible to spread the pathological process hematogenically from one organ to another. It was also found that the dorsal surface of the rectum is the most blood-supplied, as opposed to the ventral one. The obtained data are necessary for veterinary surgeons to determine the most rational methods of surgical interventions in operations related to pelvic organs.

Fish is a product that, under improper storage and transportation conditions, can quickly undergo putrefactive spoilage, therefore, one of the indicators of fish spoilage is the detection of free ammonia in fish samples. The determination of ammonia formed during fish spoilage is based on the fact that it forms a white cloud of ammonium chloride in the presence of hydrochloric acid. According to the intensity, the rate of cloud formation and its stability, the degree of spoilage of fish is judged. the purpose of our study was to determine the effect of the use of the drug "SmartBiotic", produced on the basis of humic acids, on the quality and safety of the fish products obtained, namely, the detection of free ammonia in the selected samples of rainbow trout.

Three groups of rainbow trout fingerlings (Oncorhynchus mykiss) were formed to conduct the study. One group served as a control, and the other two were experimental subjects. The first experimental group of fingerlings received the drug at a concentration of 0.15%, and the second experimental group – at a dose of 0.25%. In the control group of rainbow trout, the drug "SmartBiotic" was not used.

Fibrinogen (FG) is a protein that plays a key role in the hemostasis system and is most susceptible to oxidative modification compared to other plasma proteins. FG undergoes post-translational modifications that can potentially disrupt its structure and function.

For the first time, using high resolution mass spectrometry (HPLC/MS/MS), the consequences of hypochlorite (HOCl)- induced FG oxidation were studied, and a list of FG amino acid residue oxidatively modifications. Samples of nonoxidized and treated with 50 μM HOCL fibrinogen were analyzed by mass spectrometry and it was found that many amino acid residues localized in all three polypeptide chains and the main structural elements of fibrinogen, with the exception of the E region, are involved in oxidation.

Thus, the amino acid residues localized in the E region, which are involved in thrombin binding, were not subject to oxidative modification, which indicates the preservation of the thrombin-binding sites of the fibrinogen molecule during oxidation. The αС region contains the largest number of oxidizing sites, which confirms the hypothesis that this region can serve as a trap for reactive oxygen species (ROS) molecules.

The aim of the study was to evaluate the production of lymphokines by piglets' T-lymphocytes during the disease of acute nonspecific bronchopneumonia, in response to nonspecific mitogens in vitro. Blood from 3.5-month–old piglets of a large white breed was used as a model for the study (group 1 - patients with clinical signs of lung disease - underwent antibiotic and vitamin therapy in appropriate doses, group 2 - clinically healthy - intact were under observation). The functional activity of T-lymphocytes was evaluated in vitro, the level of lymphokine production in the reaction of inhibition of leukocyte migration (RTML) with nonspecific mitogens of T-lifmocytes - concanavalin A (Con A) and phytohemagglutinin (PHA) was taken into account before treatment and 7, 14 and 21 days after its initiation. In the first days of the disease, it was found that lymphocytes isolated from sick animals react differently to the introduction of concanavalin A and phytohemagglutinin cells into the culture – the reaction in response to PHA is more pronounced. The percentage of inhibition of leukocyte migration in response to the introduction of PHA and KonA was the lowest for the entire study period on the 7th day of treatment, which characterized the highest production of lymphokines in response to both mitogens. From the 14th day, the production of lymphokines in both cases was not as active. This is due to the fact that at the beginning of the inflammatory process, T-lymphocytes actively produced lymphokines that inhibit the migration of leukocytes, which should contribute to the formation of a focus of inflammation and limit secondary alterations. After antibiotic treatment and relief of the inflammatory process, chemotactic stimuli acquire the opposite orientation, this contributes to the dispersion of immunocompetent cells from the focus of inflammation and is necessary for the adequate course of proliferative processes in the lung tissue.

Common carp and African catfish belong to the Cyprinidae (Cypriniformes) and Catfish (Siluriformes) orders, respectively. They are characterized by a different habitat, as a result of which the structure of the gill apparatus has a number of features [3]. The article describes the macroscopic and microscopic morphology of the gills of the represented fish species. Each of them had four complete pairs of gills, and the fifth was rudimentary without gill filaments. The gill rakers of carp tended to be short and widely spaced compared to the long and thin rakers of catfish. The gill filaments of the carp were longer than those of the African catfish, indicating a larger area of the gill surface in the former species. All gill regions, as seen from light microscopy, are covered with mucous epithelium.

The paper presents the results of a morphological study of the blood of dogs of service breeds, in which signs of chronic kidney disease were detected. Often, the pathological condition of the kidneys develops as a secondary process due to intoxication of endo- or exogenous origin, infectious and invasive diseases. The danger of chronic kidney disease is that the owners or maintenance staff notice the appearance of animal health problems already in the late stages, when conservative treatment most often cannot give positive dynamics. During a clinical blood test, it was found that the dogs of the experimental group (patients) had erythropenia and hypochromemia, which were most likely associated with impaired renal function, and, as a consequence, decreased erythropoietin secretion. Of course, the decrease in the number of red blood cells caused a significant decrease in the hematocrit value to the level of 31.5 ± 5.6 l/l, which was 26.9% lower than the level of this indicator in healthy animals. When analyzing the leukogram, a picture of neutrophilia with a shift of the nucleus to the right was noted. The percentage of lymphocytes in the leukogram of sick dogs was 2.7 times lower than in healthy dogs, which can be considered a relative change in the percentage due to increased neutrophil counts. If we talk about the total content of leukocytes in the blood, no significant changes were found. Thus, during the study of the blood of dogs of service breeds with signs of chronic kidney disease, signs of hypochromic anemia were established.

ed in fur farming in the Russian Federation. In the literature, there are often materials on the anatomy of representatives of the mustelid family, such as the American mink, American polecat, American marten and others. Along with this, in modern morphology there is practically no information about the anatomy of sables, and in particular about the black Pushkin breed. The purpose of this study is to study the structural features of the liver in the Pushkin black sable breed, as well as to determine its morphometric characteristics in the studied animals. During the study, the corpses of the black sable Pushkin breed were used. In total, fifteen corpses of sables of the black Pushkin breed aged two to three years were examined. To study the structural features of the liver, traditional anatomical techniques were used. According to the results of the study, it was found that the sable of the black Pushkin breed has six lobes, since the average lobe has no independent significance in the anatomy of the liver; the most developed lobes of the liver are the right medial lobe and the left lateral, and the least developed square and caudate lobes.