In the conditions of the Republic of Belarus there were determined the parameters of acute and subacute toxicological characteristics of the developed in the Vitebsk State Academy of Veterinary Medicine anthelmintic preparations of durable action Febolvetum-О for control of sheep strongylatosis and Febolvetum for control of strongylatosis of cattle young stock. Data on determination of toxicological parameters of the prolonged action bolus were presented. Research results showed that the preparations did not render negative influence on laboratory animals (white mice). According to the parameters of acute oral toxicity the Febolvetum was qualify as the third hazard class. In accordance with the results of study of subacute toxicity parameters of the preparations, it was concluded, that in the conditions of free feeding of Febolvetum boluse in combination with forages in course of 30 days in doses of 200 mg/kg; 150 mg/kg; 100 mg/kg of body weight in animals there were found no signs of intoxication; there were not stated any is not fixed deviations in physiological state; and were stated no mice death.

The methods and results of determination of safety and relative biological value of carps (Cyprinus carpio) with philometroidosis and breams (Abramis brama) with ligulosis depending on infestation intensity with application of test-object Tetrahymena pyriformis realized in the conditions of the Republic of Belarus were presented. Research results showed that lowering of reproduction degree of protozoan on 20-30% could testify to the presence of light toxicity. Suppression of infusoria reproduction up to 30% with the simultaneous lowering of actions activity, disturbance of its character and availability up to 10% of inflected cells could testify on the moderate degree of toxicity. Lowering of infusoria reproduction degree on 30-50% with the simultaneous presence of 10-20% of cells with the affected character of motion, form and dead testified to evident toxicity of products. Lowering of infusoria toxicity on 50% and higher, presence of cysts, distorted cells, and ghosts testified to high product toxicity. Research results established that in case of high invasion intensity meat of carp philometroidosis had low toxicity (2 points). Meat of breams with ligulosis and moderate invasion intensity had low toxicity level (2 points), and in case high invasion intensity – moderate (3 points). The relative biological value in case of philometroidosis was on 13,29-28,41% lower in comparison with meat of healthy carps, and in case of ligulosis - on 18,66-57,29% in comparison with healthy breams meat

Belarus concerns a biogeochemical province with the lowered content in environment of such microelements, as iodine, selenium, copper, cobalt, manganese, zinc and some other. It conducts to infringement of intensity and an orientation of processes of an exchange of proteins, carbohydrates, lipids, and finally - to decrease in their growth and development of an organism of young growth. High cost of foreign preparations for treatment and preventive maintenance of an alimentary anaemia, low bioavailability of iron and toxicity do not provide purposeful disesase control and immunodeficiencies arising on its background. The special urgency is got by research of means of complex preventive maintenance of an alimentary anaemia and immunodeficiencies. It has been established that the recipes N1-3 have proved to be non-toxic for laboratory animals and have no effect on the meat quality.

Studying of toxicity of enterosorbent produced the basis of mixture of filtering pulvis of perlite, kizelgur and activated carbon was realized in the conditions of the Republic of Belarus by the example of healthy white mice of both sexes with body weight of 18-25 grams. Animals were divided in three groups. The tested substance was entered insitu to ventricle on an empty stomach after 12-hours of absolute diet. The first group animals were administrated the enterosorbent in doze of 5 g/1 kg, the second group animals - 2,5 g/1 kg. Glucose content increased from 3,8 +/- 0,47 to 4,3 +/- 0,17 mmol/l on the 30-th experimental day and decreased on 8,2 % on the 60-th experimental day. Cholesterin and triglyceride content lowered on 9,5 % and 11,1 %,respectively. Enzymes concentration of aspartate transaminase and alkaline phosphatase decreased from 120,0 +/- 3,87 up to 117,0 +/- 2,58 units/l and from 396,3 +/- 3,78 to 345,3 +/- 2,97 units/l, respectively. Urea increased from 3,7 +/- 0,16 to 3,9 +/- 0,17 mmol/l on the 30-th experimental day. Research results showed that mixture of filtering pulvis after the single oral administration in dose of 2,5-5 g/1 kg did not cause mice death. The analyzed mixture could be referred to the class of low-toxic substances. The mixture did not have irritation action and did not render chronic toxic action on the experimental mice

Determination of chronic toxicity of a new selenium-containing preparation Aesel was realized in the conditions of the Republic of Belarus. There was realized endermatic administration of the experimental preparation to laboratory white mice. Studying of sensitivity of some organs and systems of mice and revelation of a degree of reversibility of processes caused by active substances of the drug was realized. The main clinical, pathomorphologic, biochemical, hematological changes in the organism of laboratory animals with induced chronic toxicity were determined.

In the conditions of the Republic of Belarus by an example model of a purulent wound at rats there was realized an experimental study of pharmacological activity of a medical remedy PhytoMP (containing active substances of Macleaya microcarpa (Maxim.) Fedde of Papaveraceae family; and Plantago major L. of Plantaginaceae family) in the form of powder. It was established, that the intensity wound-healthing effect depended on a ratio of the components plume poppy / greater plantain 1 + 1:1, 2:1, 1:2. Studying of the remedy safety showed that PhytoMP in the maximal dozes was not toxic for animals after a single unitary intragastric administration in dose of 50000 mg/kg to mice and in dose of 20833 mg/kg to rats. The mentioned above indexes surpassed the recommended for human dose after application tonsilles (1,428 mg/kg) in 35014 and 14589 times, and also the recommended for human doses for application at a wound with size of 2x2 square cm (11,424 mg/kg) - in 4377 and 1824 times, respectively.

In the conditions of the Republic of Belarus there was realized clinical, biochemical, pathological-anatomical and histologic analysis of the efficiency of the national Tsinkovet (Zincovet) preparation doses in cases of experimental liver dystrophy caused by tetrachloromethane of white mice. For the modeling of toxic hepato-dystrophy there was applied tetrachloride carbon. Five tested and 2 controlled groups of scrub white mice were prepared. There were 23-29 mice in each group. Weight of mouse was 18 – 20 g. Conditions of feeding and keeping were the same in each group. 181 mice were used in the test. 5 ml/ kg of carbon tetrachloride was entered subdermal to tested group and the first controlled group mice once a day two days along. Tested dozes were estimated based on preparation toxicity. Maximum doze was 3 mg in 0,5 ml of distilled water for one mouse (1-st group - 3 mg, 2-nd group - 2, 75 mg, 4-th group - 2, 25 mg and 5-th group - 2 mg). Mice mortality was noticed during the experiment. Results of influence of different doses of the studied preparation on liver specific weight and variations of body mass were presented. Activity of amplifiers (succinate dehydrogenase (SDH), glutamate dehydrogenase (GLDH), aspartate aminotransferase (GOT), alanine-aminotransferase (GPT) in blood serum of mice after administration of tetrachloromethane and Tsinkovet preparation was analyzed. Drawings of liver acinus of hepatic steatosis were given. Research results proved that the analyzed zinc containing preparation substantially lowered the toxic action of tetrachloromethane and promoted the regeneration of liver cells

Determination of influence of long acting antihelminthics (Aversictini boluses and boluses with albendazole) and influence of usual antihelminthics (farmatsin, alverm, fenbendavet) on first stomachanimal digestion, as well as on quantity and quality composition of microflora and microfauna in first stomach and large bowel was realized in the conditions of the Republic of Belarus. In course of the experiment there were used 6 groups of calves infested with helminths (Neoascaris vitulorum, Strongylata sp.). Research result showed that different antihelminth preparations to a greater or lesser degree rendered negative influenced on quantity and quality composition of microorganisms in first stomach and large bowel of cattle. Alverm and boluses with albendazole rendered the least influence on microflora and microfauna that could be explained by low toxicity of active substance (albendazole) of the above preparations. Aversictini boluses, fenbendavet, and farmastin changed the composition of microorganisms. It could be explained by high toxicity of preparations containing aversictini which rendered influence not only of gastro-intestinal tract but also on the whole organism. Active ingredient of mentioned above preparations (Aversektin C), being the product of microbial synthesis, rendered the antagonist action on the normal microflora of digestive tract. Negative influence of fenbendavet was caused by the chemical composition of the preparation and neurotoxic action of fenbendazol

Development of new selenium preparations in a complex with vitamins for the purpose of decrease of trace element toxicity and increase of its bioavailability is the topical problem of veterinary science. A new antioxidant water-soluble complex Aesel, which includes selenium as the activated product of interaction of methionine and sodium selenite, vitamins A and E, is researched. Lethal doses of the preparation for mice and rats were identified through intragastric and subcutaneous introduction. Due to the results of the research it was determined that Aesel is rated among the forth class of danger, so it is dangerous to a very little degree. Lethal doses of the preparation on the pure selenium, calculated on Pershin method, for rats at parenteral introduction is equal 5,48, at enteral introduction - 39, for mice at parenteral introduction - 7,72 mg/kg. Lethal doses of the preparation calculated on all making components equal to 39000 mg/kg.