Epidemic situation on enzootic bovine leukosis in public and individual farms in the Republic of Dagestan

Abstract

The spread of the bovine leukemia virus impedes the development of livestock production and causes considerable losses. Despite the measures implemented, the problem of bovine leukosis eradication remains relevant in different regions of Russia. The article presents data on distribution of enzootic bovine leukosis in the Republic of Dagestan. Over the past five years, the lowest level (1.02%) of leukemia virus infection in cattle in the Republic was recorded in 2020. Laboratory tests for bovine leukosis were carried out in 41 raions and 7 municipal districts: no disease was diagnosed in 12 raions and 4 municipal districts, and the animal seropositivity index in the rest of areas was less than 1%. A high level of animal infection with the leukemia virus was recorded in the following raions: Dakhadaevsky (10.3%), Shamilsky (7.9%), Tarumovsky (3.1%), Kizlyarsky (2.3%), Babayurtovsky (2.2%), as well as in the town of Yuzhno-Sukhokumsk (3.8%). In other districts, the parameter’s values ranged from 1 to 2%. In total, 524,930 animal sera samples were serologically tested using the immunodiffusion method, out of which 5,362 samples were seropositive in 2020. 1,265 sera samples from animals infected with the leukemia virus were tested using the hematological method, 251 animals (19.8%) with persistent leukocytosis were identified, which is the average for the past years. Comparative analysis of the morbidity rate for bovine leukemia virus in farms of different categories showed that in public farms of the republic the percentage of infection level was higher (3.3%) than in the individual sector (0.7%). Thus, bovine leukemia infection level in the republic tends to decrease. Nevertheless, the infection and morbidity rates in cattle remain high in some raions and municipal districts, in particular, in the public sector.