Valdaisky National Park is a protected area located on the territory of the Novgorod region of the Russian Federation. The park was created in 1990 to preserve the natural complex of the Valdai Upland, and to organize ecological tourism on its territory.n important part of the park are water areas: within the boundaries of the park there are more than 270 lakes, the largest of which form the boundaries of the park. One of the most significant - Lake Veljo - has been the object of environmental research over the past decade. However, small lakes (Ukleinskoye and Pavlovo), which are part of the Velyo system, have not been investigated. The task of the study was to determine the ecological state of such lakes and assess their impact on the state of the lake. Vello.For the water of each studied reservoir, the main hydrochemical parameters were determined. Based on the results of the research, a water pollution index was calculated for each lake, according to the results of which they were assigned a water quality class. Both studied reservoirs belonged to the II class of quality, which characterizes them as clean. Previous studies of the Veljo waters showed the same results. Thus, on the basis of this, it can be tentatively assumed that the negative impact of the Pavlovo and Ukleinskoe lakes on the lake. Vello is missing. However, further studies of the waters of these lakes are necessary, since for many reasons the situation may change for the worse. Pollution of small lakes will also affect Veljo, which will lead to negative consequences in various industries.

Okkervil is one of the small rivers of St. Petersburg, the source of which is located on the territory of the Leningrad Region, and the mouth is within the city of St. Petersburg. The length of the river is 18 kilometers, and in its course it passes through several rapidly developing settlements, including the village of Novosergievka and Kudrovo. The Okkervil River and its coastal zone, both within the city and beyond its borders, are actively used for various purposes, including recreation and amateur fishing. However, like many other rivers flowing through the territories of large cities, the river. Okkervil is subject to diverse anthropogenic pressure, leading to water pollution. Thus, the water quality of this river may not be of adequate quality for use in fisheries and recreational purposes. The main objective of this work is to determine the chemical composition of the waters of the river and to establish its suitability for fisheries and recreational water use. Sampling was carried out during the open water period at three points with different types of anthropogenic load: outside the city, near the village of Novosergievka; at the entrance to the city; and in the residential area, near the Prospekt Bolshevikov metro station. At each point, the main hydrochemical indicators were determined: the concentrations of iron, copper, ammonium ions, phosphates, nitrates and nitrites, heavy metals, as well as the concentration of dissolved oxygen and BOD5. At all sampling points during the research period in the river, the standard values for the content of nitrites, phosphates, iron and copper were exceeded.The results obtained indicate a high level of pollution associated, among other things, with the ingress of untreated storm drains into the river, and untreated and undertreated household waste. The highest level of water pollution was noted at a point located in a residential area. The water here corresponded to the V class of quality (dirty). Both in the spring-summer and autumn periods of the study, the water of the Okkervil River in the other two sections corresponded to III-IV quality class (moderately polluted - polluted). The water quality of the Okkervil River deteriorates from the source to the mouth. In all the studied areas, the river is unsuitable for fisheries and recreational water use.

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.