The purpose of the study is to establish the mechanisms of development of oxidative stress during long-term low-dose exposure to cypermethrin on the animal organism and to substantiate possible risks. The work was carried out using Wistar rats, which were intragastrically injected daily with cypermethrin at a dose of 1/1000 LD50 for 60 and 120 days. At the same time, control animals received an appropriate volume of saline solution inside. When removing animals from the experiment, blood was taken to determine the number of red blood cells, the concentration of hemoglobin, glucose, lactic and uric acids, and total bilirubin. In the study of erythrocytes and liver, biochemical parameters characterizing carbohydrate and purine metabolism, processes of xenobiotics biotransformation, pro- and antioxidant processes were determined. Long-term lowdose exposure to cypermethrin for 60 days causes hematotoxic effects in animals, enhancement of xenobiotic biotransformation processes, and slight compensatory restructuring of metabolic processes in the liver. Exposure to 1/1000 LD50 of cypermethrin for 120 days, in addition to the above effects, causes the development of acidosis, enhances pro-oxidant processes, and suppresses the function of the antioxidant defense system and the pentose cycle. The decrease in the activity of the liver antioxidant system is due to glutathione deficiency due to the activation of xenobiotic biotransformation systems and suppression of the activity of glutathione reductase and glucose-6- phosphate dehydrogenase, which ultimately leads to the development of oxidative stress. Long-term exposure of animals to low doses of cypermethrin causes hemolysis of erythrocytes, lactic acidosis, activation of prooxidant systems, and inhibition of the antioxidant defense system. Deficiency of carbohydrates and suppression of the activity of the pentose cycle indicate a decrease in the functional activity of the liver and an increased risk of immunosuppression.

The purpose of the research is the analysis of the range of antiparasitic drugs for pig breeding as registered in the Russian Federation and included in the State Register of Medicinal Products for Veterinary Use.The control of parasitic diseases is an essential element of veterinary support for animal husbandry, and its constituent part is the use of antiparasitic drugs. The State Register contains more than three hundred drugs to control parasitic infections of animals of various species. Forty-eight drugs are allowed for use in pig breeding. The analysis of drug compositions found that they contained a limited list of compounds as active substances. For example, 17 antiparasitic drugs contained compounds of the avermectin class as active substances (12 of them had ivermectin as the active substance); 8 drugs against endoparasites contained albendazole in their composition. At the same time, the composition of combined drugs lack distinction and is a combination of two or more active substances produced in mono-preparations. To prevent the resistance in parasites, it is advisable to use a minimum required list of drugs which allows the availability of a reserve for drug rotation in the future. Simultaneous or sequential use of different drugs (including insectoacaricides based on neonicotinoids or synthetic pyrethroids to treat premises in the presence of animals) complicates the assessment of the individual drug effect on animal health and can induce immunological stress, which creates favorable conditions for infectious diseases including opportunistic infections.

The thyroid gland is very sensitive to various stress factors, including chemical ones. Meanwhile, the effect that many ecotoxicants have on the animal endocrine system has not been studied. The effect of cyanide-containing synthetic pyrethroids on the synthesis and secretion of thyroid hormones during prolonged low-dose exposure remains an open question. This research was aimed at assessing the morphofunctional state of the thyroid gland in laboratory rats under the specified exposure regime. The studies were conducted on 48 male Wistar rats. When modeling the effect of low doses of deltamethrin on animals, the substance was administered to rats at a dose of 1/100 LD50, and the experiment lasted for 120 days. The concentrations of thyroid-stimulating hormone, total thyroxine (T4), triiodothyronine (T3), and the ratio T4/T3 were determined in the rats' blood. The solid-phase enzyme immunoassay method was used to determine hormones. For histological examination, the thyroid gland of animals was fixed in a 4% neutral formaldehyde solution. Sections of paraffin blocks were stained with hematoxylin and eosin. Prolonged low-dose exposure to deltamethrin caused hypofunction of the thyroid gland in laboratory rats, which was accompanied by a decrease in the level of thyroid hormones in the blood serum. The stimulating effect of the pituitary gland increased compensatorily due to the additional release of thyroid-stimulating hormone. At the same time, there was a change in the ratio of T4/T3 in the blood. The histological patterns of the thyroid gland were characterized by a decrease in the thyrocyte area, growth of follicles, and colloid densification.

The control of endo- and ectoparasites of animals takes an important place in the complex of medical and preventive measures carried out on farms and livestock enterprises of industrial type. Considering the risk of adverse effects of anti-parasitic drugs, we analyzed the changes of biochemical parameters of blood serum in swine (commercial hybrid) with a single subcutaneous injection of Ivermin (A.D. Ivermectin) at a dose of 0.2 mg/kg with subsequent introduction of a double Azoxivet immunostimulator (A.D. Azoximer bromide) in a dose of 0.5 mg/kg and the carbon enterosorbent Zoocarb at a dose of 0.2 g/kg 2 times a day for 3 days. In 14 days after the start of the experiment, biochemical analysis of blood serum was performed using the Screen Master Analyzer and a set of reagents from the company “Human” (Germany). Statistical data processing was performed using the Student’s parametric T-Test for independent samples. The correlations between variables were evaluated using Spearman’s Rank Correlation Coefficient. It turns out that Ivermin, when administered in a single therapeutic dose causes changes in the biochemical parameters of blood serum, indicating a high risk of hepatotoxic and nephrotoxic effects. The number of correlations of symptoms with the introduction of Ivermin increases. Pharmacocorrection allows minimizing the marked changes. Statistically significant correlations of variables disappear, and this indicates a decrease in adaptive stress.

The introduction of intensive technologies in modern agricultural production involves the widespread use of chemicals to protect plants and animals, including insecticides and acaricides. However, the development of arthropods resistance to the used drugs significantly reduces the efficiency of the chemical method of controlling insects and mites. The article describes the basic mechanisms of the development of resistance on which the study of a comprehensive strategy of combating pests and pathogens in plants and animals based on. Multiple resistance in case of revealed resistance of target objects to multiple substances is of particular importance. Necessity for the development of new insecticidal and acaricidal preparations as well as the improvement of the principles of their application to slow down the development of resistance in arthropods is required. In animal husbandry, the problem is compounded by developing parallel resistance of infectious agents to antimicrobial agents. This requires the development of a scientific-based methodology of pharmacological prevention and treatment of infectious and parasitic diseases of animals, as well as chemical protection of plants against pests and diseases.

Due to diffuse distribution in the environment and migration along the food chains, pesticides affect non-target organisms, including during embryonic development. The prenatal period is a “critical window” of development for the body when the basic organs and systems are laid and formed. Even a slight effect on the body of ecotoxicants in this period can lead to developmental defects and further increases the risk of diseases and reproductive dysfunction. The studies examined regarding a low-dose, without visible clinical manifestations in mothers, prenatal exposure to pesticides, imitate the real conditions for the intake of toxicants in small quantities during pregnancy at different stages of embryonic development. The authors found that pesticides are capable of causing metabolic shifts and delayed behavioral changes in the offspring, which are a manifestation of the non-monotonous dose-response reaction associated with the presence of epigenetic mechanisms.

Many toxic substances in low doses daily enter the body of animals and humans with food. In this case, the main burden of the transformation and excretion from the body have the organs of excretion and detoxification. This review summarizes the results obtained on different experimental models and reflecting the impact of pesticides on the gastrointestinal tract, liver and kidneys at low doses chronic intoxication. It is established that, entering the body in low doses, pesticides cause a change in the morphological structure of the intestine and the enzymatic activity of the enterocytes, as well as help reduce the barrier function of the gastrointestinal tract and the development of dysbiosis. When exposed to pesticides there are also changes of biochemical processes in the liver and decrease its functional activity, impaired kidney structure. The original state of health and genetic features of stress-limiting systems determine the severity of the changes and level of post-toxic complications risk.

Adsorption properties of modified carbon sorbents with respect to pesticides used in agriculture as insectoacaricide means, ivermectin and deltamethrin, were studied. The distinctive features of the adsorption of the pesticides by carbon sorbents, associated with their porous structure and with the nature of modifiers and given preparations, were determined under model conditions on real systems.

The role of pesticides in the development of endocrine disorders and neurodegenerative diseases of humans and animals is currently being actively discussed. Epidemic and model studies confirm the link between the use of pesticides in agriculture and the occurrence of adverse changes in the nervous and endocrine systems of people and animals. But the mechanisms underlying pathological changes have not yet been identified. Among the leading links in the pathogenesis of neurotoxicity, oxidative stress, neuroinflammation and epigenetic modification can be distinguished. The cause of endocrine disorders may be low-dose hormone-like effects of pesticides, leading to changes in the synthesis and metabolism of the body’s own hormones. Due to the difficulty of establishing cause-effect relationships, as well as the presence of significant gaps in the study of the pathogenesis of chronic pesticide intoxications, further studies of the biological effects of low doses of pesticides are necessary in order to establish patterns of their influence on the population health of people and animals.