Epizootic situation on cattle tuberculosis in the Omsk region

The purpose of research is to study and assess the current epizootic situation regarding tuberculosis in the administrative-territorial formations of the Omsk Region based on the results of allergic and bacteriological studies. The paper presents the results of an analysis of data from allergic and bacteriological studies on bovine tuberculosis conducted in the Omsk Region from 2016 to 2022. It is shown that after an increase by 2018 to 0.28 % of cases of detection of positive reactions in animals to intradermal administration of tuberculin subsequently noted a gradual decrease in their number to 0.10 % by 2022. As the compiled cartogram showed, over the entire observation period, the greatest degree of spread of delayed-type skin hypersensitivity was recorded in cattle in the southern districts of the region (Moskalensky, Isilkulsky and Pavlogradsky) with the absence or isolated cases of its manifestation in the northern districts. Due to the wide distribution of non-tuberculous mycobacteria in the region, which are the main cause of non-specific reactions during allergic testing, all animals that gave a positive reaction to intradermal injection of tuberculin are examined by palpebral test, which prevented the unreasonable slaughter of a significant number of cattle. Of the responders, from 1.73 to 4.32 % of heads with pronounced swelling were identified annually when the allergen was introduced into the thickness of the eyelid, with the most frequent cases of reaction observed in the Kalachinsky, Sargatsky, Lyubinsky, Pavlogradsky, Moskalensky and Isilkulsky Districts. When conducting bacteriological studies of biological material from forcedly killed animals over the entire period of observation, 33 strains of bovine mycobacteria and 7 strains of NTM of groups II and III according to the Runyon classification were isolated. Despite the significant improvement in the epizootic situation, the problem of bovine tuberculosis in the Omsk Region remains relevant today due to cases of registration of isolated foci of infection in the Isilkulsky, Tavrichesky and Muromtsevsky Districts of the Omsk Region.