Analysis of the episootic situation of cattle leukemia in the Siberian Federal District

The analysis of the epizootic situation of cattle leukemia in the Siberian Federal District as a whole and in individual regions of the district is given. The study was carried out in the Republics of Altai, Tuva and Khakassia, in the Altai and Krasnoyarsk Territories and in five regions: Irkutsk, Kemerovo, Novosibirsk, Omsk and Tomsk. The materials of diagnostic studies obtained by veterinary specialists of the Siberian Federal District for 2017-2019 are presented. This information has been analyzed and summarized both for the Siberian Federal District as a whole and for its individual constituent entities. Studies show the spread of bovine leukemia virus infection in the whole district. A tense epizootic situation with cattle leukemia was noted, since the Siberian Federal District ranks second in Russia in terms of the number of adverse locations (322). However, compared to 2017, the number of adverse locations in 2019 decreased by 57, sick animals - by 977 heads, infected animals - by 70836 heads. The number of adverse locations has decreased slightly, while the number of infected animals in some regions has increased. As of January 1, 2020, no hematologically sick animals were found in the Republics of Altai, Khakassia, Buryatia and Tuva, but the number of animals infected with BLV increased. The experience of individual regions of the country that are free from BLV infection (Sverdlovsk, Vologda, Leningrad, Murmansk, Arkhangelsk, Kostroma, Kirov regions, Khanty-Mansi Autonomous District, etc.) shows that bovine leukemia is an infection that can be controlled. It is possible to eliminate the disease in herds of cattle with any level of BLV infection as a result of carrying out complex health-improving measures, as well as organizational and veterinary-sanitary measures with the obligatory removal of sick and BLV infected animals from the herd.

Study of episootic situation and dynamics of episootic and infectious processes of bovine leukemia infection

One of the problems in dairy cattle breeding has become bovine leukemia since the middle of the 20th century in the Republic of Belarus. Initially, isolated cases of the disease were recorded according to the data of clinical signs and pathological changes in the case of death of animals and the results of veterinary sanitary examination at the section of meat processing plants. After the establishment of the infectious etiology of the disease and the introduction of the immune diffusion reaction into veterinary laboratory practice, the massive nature of its spread was established with corresponding economic losses for the livestock industry. Under the prevailing conditions, it was necessary to reliably study the indicators of the epizootic situation and the trends of the epizootic process affecting the spread of infection with the bovine leukemia virus in order to take effective measures to eliminate it. The authors considered the methodological approaches to the study of the epizootic situation and the dynamics of the epizootic process of bovine leukemia virus infection in the Republic of Belarus formed the basis of the developed monitoring system. It included 132 epizootic significant indicators, divided into 8 groups, reflecting the epizootic situation of bovine leukemia virus infection, taking into account age, sex, production, territorial and other characteristics of infectious and epizootic processes of the disease in the conditions of the Republic of Belarus, established the procedure for collecting and transmitting epizootic information for making management decisions. This made it possible to control the epizootic situation and predict its development, to determine the features and patterns of the epizootic process, to evaluate the results of diagnostic studies, the effectiveness of anti-leukemic measures and their socio-economic significance. The use of epizootic, clinical, pathomorphological, laboratory methods of research with subsequent statistical processing of the data obtained and their analysis in the monitoring system of infection of the cattle leukemia virus in the Republic of Belarus made it possible to control the epizootic situation, predict its development, determine the features and patterns of the epizootic process, evaluate the results of diagnostic research, the effectiveness of anti-leukemic measures and their socio-economic significance.