Data on working out a quantitative polymerase chain reaction (PCR) for revealing of virus of infectious bovine rhinotracheitis realized in the conditions of the Republic of Belarus was presented. The development of the qualitative PCR was realized in the following stages: analysis of viral genome and selection of primers; synthesis of primers and control of their specificity; optimization of conditions for PCR; obtaining of positive control and determination of its concentration; obtaining and testing of probe and optimization of its concentration for PCR; testing of the developed method and determination of sensitivity. The obtained method made it possible to determine not only presence of infectious bovine rhinotracheitis, but also its initial amount in sample. Due to application of probe constructed in accordance with molecular beacon technology the presented method proved to be highly specific. That was connected with the fact that fluorescence was registered only when the probe connected to complementary part of DNA, in other case the result was negative. Research results showed that the sensitivity of the given procedure made it possible to define in a sample presence of a virus with concentration 2 lg that corresponded to 2 DNA copies

Data on changes of infectious titer of Porcine Reproductive & Respiratory Syndrome (PRRS) virus depending on variability of cultivation conditions was analyzed in the conditions of the Republic of Belarus. There were determined the regimes of cultivation which made it possible to minimize the terms of virus containing material production up to 3 days. The following factors influenced the infectious titer of PRRS: adaptation to cell culture; completeness of cell culture monolayer; number cells moving into stage of logarithmic growth; infectious dose of virus; storage duration; usage intensity.

There were presented data on etiology, specific prophylaxis and treatment of the most widespread infectious diseases of fishes in the Republic of Belarus: aeromonosis, pseudomonosis, swim bladder inflammation (air bladder disease), viral branchionecrosis. For the preparation of highly efficient specific medical and veterinary preparations it was recommended during the outbreaks of fish diseases to allocate the local pathogens on the basis of which it was recommended to produce vaccines both for perinatal and immersion administration for their wide use both for commodity fishes and for different ages and categories

A method of development of highly purified antigen of a virus of classical swine fever (Sinlak strain) for definition of antibodies in enzyme multiplied immunoassay (ELISA) was tested in the conditions of the Republic of Belarus. There were determined parameters of sensitivity and specificity. There was developed a method of partial purification of the antigens by means of obtaining of infected leukoconcentrate, settling of virus by means of ammonium sulfate with the further ultrafiltration through a membrane