An interpretation of concepts 'norm' and 'pathology' in the veterinary medicine and medicine from the point of dialectic and materialistic theory was analyzed. There was given an interpretation of 'norm' as a complex of average indexes of state of vital function of body; interpretation of pathological process, pathological conditions and diseases. There was analyzed the philosophical concept of reasons and consequences in etiology and pathophysiologic mechanisms of diseases, as well as criticism of terms causalism and conditionalism

State of immune system of broiler chickens after administration into their diets of nonspecific immunostimulative drugs – bacterial liposaccharide Alveozan and spore-forming aerobic bacterium Bac. Alvei (KMIEhV-11) and probiotic on the basis of lactic acid bacillus Dialakt was studied in the conditions of the Republic of Belarus. In course of the study there was proved that the analyzed preparations had expressed immunogenic activity, rendered the positive influence on natural resistance of broiler chickens. Under action of preparations Alveozan and Dialakt in broiler chickens there were stated the following changes: improvement of protein absorption from gastro-intestinal tract in chickens at the age up to 19 days; there was achieved a hepatic protection effect at birds at the age up to 36 days. The specified changes did not depend on application regimen of the given preparations.

Research on working out of a new fodder additive on the basis of rape (Brassica napus) phospholipids which included mineral substances necessary for normal functioning of cattle was realized in the conditions of the Republic of Belarus. Results of biochemical analysis of 35240 blood samples revealed that 15-40% of studied animals had abnormalties in vitamin, protein and mineral metabolism and lowering of immunobiological disease resistance. There was correlation dependence between the degree of metabolic orders and the state of forage reserve of a forage reserve. The lowering of forage reserve caused the increasing of metabolic disorders. As a whole forages of the surveyed farms were low in content of copper, zinc, cobalt and selenium and could not provide physiological requirements of animals without introduction into rations of specialized additives

Study of subclinical chlamydial endometritis of black and motley cows of 2-5 lactations with 5000-6000 kg milk per year was realized in the conditions of the Republic of Belarus. Research results showed that reaction of pH medium of uterus content of healthy ill cows with subclinical chlamydial endometritis did not change and was within the limits of 8. Diagnostics of subclinical chlamydial endometritis during estrum was realized according to presence of estrous mucus in purulent inclusions, as well as of neutrophil in tissue smear and by colouring by Stamp of tissue smears from a uterine lining and in serological reactions. In inter-estrous cycle it was possible to establish a latent chlamydial endometritis according to slightly opened uterus channel, state of uterus walls and presence of yellow bodies in an ovary, increasing of titers in antibodies in two and more times in dual tests of serum.

Data оn evaluations of therapeutic efficacy of albendazol and fenbendazol agaonst acute and chronic forms of larval cestodiasis of animals were studied in the conditions of the Republic of Belarus by an example of experimentally infested sheep and rabbits. Application of albendazol and fenbendazol both separately and in complex with antioxidant vitamin and mineral additive against the chronic forms of cysticercosis tenuicollis and cysticercosis pisiform was inefficient. But application of albendazol against acute form of cysticercoses caused the lowering of invasion intensity in shepp and rabbits in 3 times, fenbendazol – in 2,6 times. Application of anthelmintic agents in complex with vitamin and mineral composition promoted the lowering of invasion intensity (in 5 and 4,1 times, respectively) and prevented the disease development in 60% of animals.

In the conditions of the Republic of Belarus there was developed a concept for differentiation of eimeria and helminthes using a system of identification indexes as mathematical expressions of morphometric correlations of eimeria oocystae and helminth eggs morphology. There was developed a method for identification eimeria species on the basis of two-dimensional mathematical analysis of oocysts using a new identification index which represented a duplication proportion of contour perimeter to surface area of an oocyst.

Realized in the conditions of the Republic of Belarus experimental infestation of American mink with monoinvasion of Strongyloides martis and parasitocoenoses of Strongyloides martis and Eimeria vison caused significant changes of hematological blood indices. Associations of the nematodes and coccids caused more intensive changes of blood morphological composition in comparison with monoinfection. The level of hemoglobin and erythrocytes at monoinvasion decreased on 18,8 % (р less than 0.05) and 23,3 % (р less than 0.05); in the conditions of an associative form - on 19,1 % (р less than 0.05)) and 31,4%, respectively; at the same time the quantity of leukocytes increased at monoinvasion on 41,3 % (р less than 0.05)), at the associative form - on 54,2 % (р less than 0.05)). In leucogram there were stated an eosonophilia and netrofilia.

Development of highly efficient antigens for an early immunodiagnosis of cattle fascioliasis (Fasciola hepatica) and studying of its main properties was realized in the conditions of the Republic of Belarus. Received in result of the experiment antigens possessed high specificity and were suitable for use in fascioliasis immunodiagnostics. Research results showed that use of indirect fluorescent (IFA) test and immunodiffusion test for fasciolasis immunodiagnostics of cattle excludes false positive results caused by tuberculosis and hypodermotosis (p less than 0,001).

Determination of interactions of monoinfestations and associations of parasites with the normal microflora of intestines of sheep was realized in the conditions of the Republic of Belarus. In the conditions of low associative infestations with Moniezia sp., Strongylata and Strongyloides nematodes, Eimeria protozoa there were stated changes in intestine microflora of sheep: sharp decrease of quantity of bifidus bacteria and lactic acid bacillus, colibacilli with the simultaneous presence of lactose-negative Bacillus coli, increasing number of aerobic bacteria. Recovery of monieziae in the conditions of presence in parasitocoenosis composition of nematodes of suborder Strongylata and Strongyloides species, Eimeria promoted the restoration of quality and quantity composition of microflora of sheep gastrointestinal tract

Analysis of synchronization of oestrus of cows by means of Ovsynch and Pre-Synch methods was realized in the conditions of the Republic of Belarus. Research results showed that estrus synchronization by means of Pre-Synch method proved to be more efficient by means of higher percentage of fertilization after the first and second insemination in comparison with Ovsynch method. Treatment of cows with the substances Surfagon and Tetravit for synchronization of oestrus did not render negative effect on milk quality and safety.