The aim of this study was to compare serum nitrotyrosine concentrations in healthy dogs with those in dogs with myxomatous mitral valve disease (MMVD). Fifty client-owned dogs were included in this study. Based on echocardiographic results, dogs were categorized into healthy (control), mild-, moderate-, and severe-MMVD groups. Serum nitrotyrosine concentrations were determined from enzyme-linked immunosorbent assays. No significant difference between control dogs and dogs with mild MMVD was detected (p = 0.31). However, dogs with moderate MMVD had significantly higher serum concentrations of nitrotyrosine (p = 0.04) than that in controls, and dogs with severe MMVD had significantly lower serum concentrations of nitrotyrosine (p = 0.03) than that in moderate MMVD dogs. There were negative correlations in the association of serum nitrotyrosine with age (n = 30, R2= 0.067, p = 0.27), left atrial-to-aortic root diameter ratio (n = 30, R2= 0.02, p = 0.57), and platelet count (n = 30, R2= 0.39, p = 0.003); however, only the platelet correlation was significant. Among dogs with MMVD, there was no significant difference in serum nitrotyrosine concentration between males and females. The results of this study suggest that tyrosine nitration end-products might be potential biomarkers for the detection of MMVD in dogs.

In the conditions of the Republic of Belarus there was produced a trial series of hyperimmune serum against livestock animals colibacillosis and there was realized the quality control of the analysed biological preparation. Research results proved that the developed serum was sterile, safe and had high immunogenetic activity. In course of quality control there were considered the following indexes: determination of physiognomy, colour, presence of visually accessible particulate matters; determination of safety and harnfullness; determination of activity; determination of concentration of hydrogen ions; determination of sterility; determination of serum volume in consumption package. For serum production there were used strains E.coli O9, O78, O0, O117, O26, O139, O15, O41, O55, O115, O141, O8, K88, K99, F41, 987P. For the production of trial series there was realized cultivation of Escherichia on the special nutritive media. There used bulls as serum producers

Analysis of data on distribution of clinicopathologic symptoms of rhinotracheitis, parainfluenza-3, bovine viral diarrhoea, clamidiosis, rhinosyncytial virus, adenovirus diseases, rotaviral diseases, coronavirus infections of cattle, viral transmissible gastroenteritis, and respiratory reproductive syndrome of swine, rinderpest, rabies and Aujesky disease of agricultural animals in the conditions of the Republic of Belarus was realized. There were given descriptions of diagnostic tests and vaccines for disease prevention used in Belarus and other countries. Treatment regimen and methods and other elements of prophylaxis were presented. There was given an analysis of prophylactic efficiency of produced medicine drugs

Analysis of the epizootological situation in infectious diseases in the world and the Republic of Belarus was presented. The prevention and eradication control strategy of mentioned diseases in Belarus was defined. In Belarus there was stated no cases of special danger infectious diseases of cattle: bovine spongiform encephalopathy; highly pathogenic poultry flu; aphthous fever; since 1982 - Bang's disease; since 1980 - Newcastle disease; since 1999 – anthrax. Preventive maintenance of 30 infectious diseases was based on application of specific prophylaxis.

In the conditions of the Republic of Belarus there was developed a production technology and there were produced samples of lyophilizated live vaccine against Aujeszky's disease of swine which corresponded to all parameters of control. The vaccine had an expressed phylactic power, induced the development of long-lived immunity of vaccinated piglets.

Usage of biological preparation of high antibacterial activity allows to decrease the air pollution by bacteria of colon bacillus group at 25-100%, increase productivity at 17-67 g, safety – at 0,4%, resistance, protein metabolism, protein fractions and some other indices (lysozyme and betalysine activity, leucocytes, erythrocytes, hemoglobin, calcium, phosphorus, iron, magnesium, AST, ALT, urea, cholesterol, bilirubin and glucose)

Application of antiviral preparation Mixoferon for poultry is studied. It is established, that Mixoferon application does not influence negatively on organism of hens, increases intensivity of protein metabolism, including the maintenance of antibodies in blood whey. Mixoferon in dozes of 2,5 ml (500000 МЕ), 1,5 ml (300000 МЕ), 0,5 ml (100000 МЕ) can be used for preventive maintenance and therapy of virus infections of hens

For the well-timed prevention and treatment of sick animals there was analyzed the therapeutic efficiency of a produced survivor serum against acute respiratory diseases of sheep and lambs, as well as Catosal in combination with Nitox 200 against the mixed flow of parainfluenza-3, adenovirus, respiratory syncytial, chiamydial and pasteurellosis infection. Comparative efficiency of all mentioned preparations was presented. Research results showed the correct and timely application of drug preparations as well as their qualitative selection made it possible to lower the death cases. Application of the presented survivor serum in combination with Nitox 200 and Catosal made it possible to lower the loss of cattle in 4-5 times and increase the viability rate of animals

In the conditions of the Republic of Belarus there was determined the therapeutic efficacy of combined application of a complex antibacterial veterinary drug (containing lincomycin and spectinomycin) and Trivitim for the treatment of calves with respiratory diseases. In course of the study of 12 1-1,5 month old calves with respiratory diseases there were analyzed the hematological blood indexes, white blood cell differential and content of total protein in blood serum before the beginning of treatment and on the seventh and fourteenth days after beginning treatment. Research results showed that application the antibacterial veterinary drug in complex therapy with Trivitim in treatment of calves proved to be efficient. Their administration shortened the terms of recovery and prevented animal death as well as promoted the normalization of hematological and biochemical blood indexes.

Results of serological examinations of blood serum of sheep on revelation of virus respiratory infections (parainfluenza-3, adenovirus and respiratory syncytial) realized in the conditions of the Kyrgyz Republic were presented. Research results showed that in farm and peasant farm holdings of all studied districts of the Kyrgyz Republic of three types of pneumo viral infections simultaneously give high levels of antibody titers in relation to parainfluenza-3 – 1:128, adenovirus – 1:32, respiratory syncytial infection – 1:16. In some districts sheep population was diseased only by parainfluenzal infection in relation with titer of specific antibodies 1:256