One of the negative factors of ionizing radiation on the body is the formation of active oxidants, which are protected by the antioxidant system. The effect of high doses of radiation on the antioxidant system of animals has been studied well, but there is not enough information about the long‐term effects of low doses. The study of the effect of pre‐threshold radiation doses on the main indicators of antioxidant protection of cattle was the purpose of our research. The research was carried out in JSC "Osminskoye" of Slantsevsky district and JSC "Plemzavod " RAPTI" of Luga district of Leningrad region on healthy lactating cows aged 3–4 years in the amount of 8 heads from each farm. Radio ecological characteristics of agricultural land JSC "Osminskoe" was as follows‐the density of radioactive contamination of the soil on 137Cs more than 1 Ci/km2, the power of the exposure dose on the ground 35–48 μr/h. Similar indicators of land in JSC "Plemzavod" RAPTI " were less than 0.5 Ci/km2 and 6–19 μr / h. Both farms use their own fodder base (hay, silage, root crops), concentrated feed produced by JSC "LKKZ", the animals are kept in summer walking, which allows us to talk about a similar dose load due to external and internal irradiation. In cows, catalase activity was determined in serum, and malone dialdehyde concentration and superoxide dismutase activity were determined in plasma. The results of the study showed that the activity of superoxide dismutase in cows from JSC "Osminskoye" was 4.15±0.46 U/mg Hb, catalase ‐ 14.54±1.03 mkat/l, and the level of Malon aldehyde ‐ 3.71±0.68 μmol/l. Similar indicators in animals from JSC "Plemzavod "RAPTI" were as follows ‐ 6.3±0.75 U/mg Hb, 9.77±0.62 mkat/l and 2.23±0.12 μmol/l. Intergroup differences of the studied indicators were statistically significant. Analyzing the results of the study, we can say that chronic stimulation of the antioxidant system by active oxidants leads to a decrease in the level of superoxide dismutase in cows by 34.1%. Probably, as compensation, there is an activation of other enzymes, in particular, an increase in catalase activity by 1.5 times. However, the compensatory capabilities of other elements of the antioxidant system are not able to fully neutralize free radicals, as evidenced by an increase in the concentration of malon dialdehyde by 66.4%.The study shows that cows long‐term in conditions of higher pre‐threshold doses of external and internal radiation occurs chronic oxidative stress, manifested by an imbalance of individual links of the antioxidant system.

No abstract

Chukotka is the only region of the Russian Federation where traditional fishing of marine mammals, including the gray whale Eschrichtius gibbosus, is conducted. More than 70% of the indigenous population of the coastal settlements of the Chukchi Peninsula eat the meat of marine mammals. Due to the huge distances between communities, lack of infrastructure, limited access to medical and veterinary care, isolated studies of marine mammal infestation with trichinella larvae are being conducted. For the first time, trichinella in the Pacific walrus Odobenus rosmarus divergens in Chukotka were recorded in the coastal zone of the Bering and Chukchi Seas in the 1970s. In the future, trichinosis has not been studied in this region, which confirms the relevance of our work. Infection of marine mammals was studied by trichinelloscopy (compressor and biochemical). Bioassays were collected during fishing by sea St. John's wort in the village of Lorino. Infection rates were determined. Studies conducted on the Chukchi Peninsula confirmed the infection with trichinosis of the Pacific walrus and revealed the larvae of trichinella in lakhtak Erignathus b.nauticus and ringed seal Phoca hispida, and later in larga Phoca largha. The extent of invasion varied from 0.9% in larga to 4.3% in lakhtak. The gray whale is the most popular food item in the diet of the indigenous inhabitants of Chukotka. According to the results of the research, out of 119 individuals of gray whales, trichinella were not found. Given the trophic‐chorological connections of marine mammals, it is difficult to imagine a way of transmission of trichinella in marine ecosystems. However, previously obtained research results allow us to do this. On the Arctic coasts, especially near settlements, there are a large number of corpses of dogs, cats, rats, voles, carcasses of small seals that fall into marine ecosystems. Invertebrates, their adult and larval forms, as well as vertebrates ‐ fish and birds ‐ occupy an important place in the process of disposal of corpses. Studies have shown that various types of invertebrates from 1 to 59 hours, and vertebrates from 28 to 95 hours can be direct or indirect sources of the pathogen of invasion and contribute to their mechanical transfer. Thus, in the conditions of coastal Arctic marine ecosystems, successful circulation of trichinella is carried out, thanks to human economic activity and the specifics of the trophic‐horological relationships of obligate and potential host species. Therefore, monitoring of trichinella invasion in these regions is vital.

Many stress factors influence pets in urban areas. The goal of this research is to understand the effects of an adaptogen called Klim Pet. Our study presents how Klim Pet affects dogs and specifically its psycho‐emotional, and somatic levels. The study involved 15 dogs aged from 1.5 to 12 years. All of them live in urban environments with symptoms of chronic stress caused by various factors. For example, loss of the owner, participating in exhibitions, active breeding, moving to a new place of residence, and the fear of loneliness. All animals were given Klim Pet for 21 days in a dosage of 1 pill per 10 kg of weight one time per day. The blood sample was taken before and after consuming the drug for morphological and biochemical research. As a result, we got a significant decrease in white and red blood cell count, as well as a decrease in the concentration of hemoglobin and ESR. The ratio of leukocytes in the leukogram approached the normative values, and the level of protein and albumin reliably increased. As a result, we got a decrease in urea and creatinine levels, as well as a significant decrease in the level of bilirubin and enzyme activity ‐ ALT, AST, and alkaline phosphatase. All of these factors represented a normalization of anabolic processes. Changes in blood composition were accompanied by positive clinical manifestations. Animals noted the normalization of appetite and digestion on the 5th‐10th day after taking the drug. The neurological symptoms were leveled (destructive behavior, tremors, unmotivated aggression, obsessive behavior) after 14‐18 days of taking the adaptogen. By the 20th day, we recognized an improvement in the condition of the skin and fur. The shedding mostly stopped or decreased, and the coat has become thick, shiny. The use of the drug Klim Pet had positive effects on clinical conditions. It neutralized the action of various stress factors and had a hepatoprotective effect. Klim Pet optimized metabolism, as well as the immune and nervous systems, and improved the condition of pet's fur and skin.