Fishing is one of the most significant factors of anthropogenic influence on the fish population of water bodies. However, when assessing fishery activities, often limit themselves to studying only industrial fisheries undeservedly ignoring amateur fishing. At the same time, the catches of amateur fishermen are not only comparable with the industrial ones, but often significantly exceed them. The Gorky and Cheboksary reservoirs are located on the territory of six constituent entities of the Russian Federation. This area is densely populated and subject to significant anthropogenic impact. Recreational fishing is widespread here and, in most cases, is uncontrolled, which makes it one of the strongest factors affecting aquatic biological resources. The article provides information about the features of amateur fishing in the Gorky and Cheboksary reservoirs. The work used a comprehensive epizootic approach, expert assessments and verification methods. It was found that the attendance of the Cheboksary reservoir by amateur fishermen is higher than that of the Gorky one. The main gear used in reservoirs are bottom gears, spinning and float fishing during the open water period; fishing with a jig in winter. There is a significant by-catch of smaller fish. The main object of amateur catches is perch. For other dominant species, catches in water bodies differ. On the Cheboksary reservoir, amateur catches have a high proportion of silver bream, bream, and roach. Thus, when assessing the level of fishing load in the reservoirs of the Middle Volga, it is necessary to take into account the scale of amateur fishing, including unorganized fishing

The Cheboksary reservoir is a highly productive reservoir with large capabilities receiving capacity for phytoplankton (silver carp), benthos (sterlet, carp), low-value and non-commercial fish species (pike). During the entire existence, the Cheboksary reservoir did not have its own compensatory object - a spawning and growing farm (NVH). The work uses a comprehensive epizootic approach, factorization, expert assessments and verification. Information was collected characterizing the artificial reproduction of fish in the Cheboksary reservoir during the existence of the reservoir. An assessment was made of the reservoir's receiving capacity in terms of the fodder base and the possibilities of stocking it with young sterlet, carp, pike and silver carp were analyzed. Analysis of data on the release of juveniles into the Cheboksary reservoir in recent years (2009-2019) shows that the actual volumes of stocking are many times lower than the potential capabilities of the reservoir in terms of receiving capacity. With the full development of the possibilities of emissions juveniles of commercially valuable fish species, productivity will increase by more than two orders of magnitude (110 times) from 0.333 to 36.8 kg / ha or from 36 to 3974 t. Currently, of fish stocking volumes is scanty - 0.3 % of the potentially possible. To realize the high potential fish-producing potential of the reservoir, it is necessary to regularly artificially release juveniles of commercially valuable fish species. Emissions of juveniles occur in small volumes and irregularly. It is necessary to build permanent compensation facilities - spawning and growing farms.

The Russian Federation is a country officially recognized by the OIE as free from peste des petits ruminants (PPR). The Russian Federation is a country officially recognized by the OIE as free from transboundary animal disease. The non-free from PPR border countries creates threat of the introduction of this infection into the Russian Federation. The aim of the study was to establish the possible rate and extent of the spread of peste des petits ruminants both between farms and within farms when the infection is introduced into the territory of the Russian Federation. To estimate the possible number of secondarily infected animals and farms, an approach based on the concept of the base rate of reproduction with exponential initial growth was used. Monte Carlo simulation was used. The results show that 22 (95 % confidence interval: 6-30) animals may be infected within 1 week after the introduction of PPR into an intact herd, while at the inter-herd level, a secondary outbreak may occur 5 (1-17) days later. The data obtained allow us to speak about the minimum required level of depopulation of 19 % of farms and vaccination of 89 % of livestock in farms of the threatened zone. The results of the study create prerequisites for the development of measures to manage this risk within the framework of maintaining the welfare status of the Russian Federation for peste des petits ruminants.

In the work, a detailed study of drugs for dogs was carried out: azinox, albena and azinox-plus. Corresponding experiments were carried out on dogs and puppies that were infected with helminths. They were examined twice to reveal the presence of helminths using different methods. Here are the results of the analyzes. The effectiveness of these drugs was found out separately for each type of helminths. Against monoxenic helminths, Azinox effectiveness 10 days after treatment of the animal reached IE 74.3-79.0 %, and EE 75.7-76.5 %. The same drug against cestodes was effective in 95.6-94.0 %and 98.7-98.8 %. We consider it necessary to note that on the twentieth day, the effectiveness of the drug against cestodes was EE 100 % and IE 100 %. Against nematodes, its effectiveness on the twentieth day ranged from 84 to 100 % and from 87 to 100 %. The next drug, Azinox-plus, showed high, 100 % efficacy against helminths such as cestodes and nematodes. Speaking about Albene (a highly effective anthelmintic drug used against dangerous endoparasites), it should be noted that after ten days against cestodes, its effectiveness reached 93 and 94 %. Against nematodes, the same drug was effective up to 93 and 93 %. Twenty days after the treatment of the dog, the effectiveness of Alben against cestodes was 97-98 and 95-96 %, and against nematodes 96-98 % and 99-99.4 %. The given data show that the effectiveness of these drugs ranges from 75.7-100 %.

In trematodes contaminated farms there is an increase in the culling of young animals and cows at the beginning of lactation with signs of hepatitis, jaundice, digestive disorders and a decrease in productivity against the background of general exhaustion. The aim of the study is to study the age and seasonal dynamics of infection with trematodes in cattle. The study of the epizootology of dicrocoeliasis of cattle was carried out at different times of the year according to coprological surveys of 278 heads. Intravital diagnostics was carried out by examining fecal samples by the flotation method and the results of helminthological dissections of the liver and gallbladder in 55 animals in July, October, December and April, taking into account the data of the state veterinary and sanitary examination laboratories of the Altai region. The extensiveness of invasion increased with the age of the animals and up to a year was 2.9% when finding 11.2 ± 1.5 eggs of dicrocoelium. The increase in extensity and intensity of invasion is associated with the accumulation of helminths in the body of animals with annual infection in the grazing period and a high lifespan of dicrocoelium. According to the data of parasitological studies, it has been established that cattle are infected with dicrocoelium during the year. The extent of invasion varied from 2.9 to 10.8 %.

Diseases of the respiratory system occupy a priority position among the non-infectious pathology of young animals. The greatest economic damage to farms of various types is caused by bronchopneumonia. The treatment of this disease brings high economic costs, in contrast to preventive measures, and especially aerosol administrations of herbal preparations. In this regard, the study of the nature and degree of the effect of herbal preparations on the animal and the improvement of preventive measures are an urgent topic of research. The authors have carried out a large amount of work on clinical research, morphology, biochemistry and immunology of blood. Based on the studies carried out, the authors have established a positive preventive effect, which is directly related to the activation and strengthening of immunity. Experiments carried out on the prevention of bronchopneumonia in calves using biostimulants of plant origin have shown high efficiency. After all treatment cycles, no culling of animals was observed, which was noted in the control group. The results obtained make it possible to recommend the aerosol use of Echinacea purpurea tincture in a dose of 3 ml per 1 m3 of the chamber for the prevention of bronchopneumonia and anemia, as well as for maintaining immunological homeostasis and the formation of the defenses of the body of calves in the farms.

The main goal of our research is to assess the applicability of various for accounting methods, to determine their limitations and to provide recommendations for their further use for assessing trends in tiger abundance and distribution. The paper analyzes the methodology for accounting for the Amur tiger and the interpretation of the primary material. The article points out the contradictions in the assessment of the number. It has been shown that, on the one hand, survival conditions deteriorate (felling intensifies, the number of the main prey species decreases), and on the other, an increase in the tiger population. Due to the death of most of the wild boar population due to the influence of African swine fever, many resistant groups of the Amur tiger will turn into separate scattered foci, and most foci may disappear. The basis for counting the number, as well as assessing the state of the tiger population, should be based on knowledge of the characteristics of the biology and the spatial and ethological structure of the population of the species. It is these tasks that the proposed express method solves, which makes it possible to identify the remaining foci (small territorial groupings). The proposed express method has a number of significant advantages. First, when using it, researchers are not dependent on the presence of snow and the season (the method can be used all year round, although the optimal seasons are autumn-winter-spring); secondly, this work is available to a small team of specialists; thirdly, the method does not require any special equipment, except for a GPS navigator. However, its main advantage is the elimination of subjectivity in assessing the presence and distribution of foci or reproductive nuclei, characteristic of the method of one-time registration, where the presence of a trace is taken as a unit of measurement.