Bovine leukosis incidence in Republic of Dagestan in 2021

Results of epizootological analysis of data on bovine leucosis (BL) incidence in the Republic of Dagestan in 2021 are reported. Bovine blood was diagnostically tested for leukosis in 32 veterinary laboratories and diagnostic offices including SBI RD Republican Veterinary Laboratory. 720,489 sera were serologically tested and 7,188 (1.0%) samples were serologically positive for bovine leukaemia virus (BLV). Among the infected animals, 527 ones were subjected to haematologic testing. Persistent leukocytosis was reported in 153 (29.03%) blood samples of haematologically tested BL diseased cattle. Statistical analysis of BLV prevalence in the republic was performed for 41 Raions and 8 municipalities. High percentage of BLV infection in the animal population was reported in fourteen Raions: Kumtorkalinsky (5.8%), Gunibsky (5.3%), Tarumovsky (3.3%), Karabudakhentsky (2.9%), Akhvakhsky (2.0%), Kizlyarsky (1.8%), Charodinsky (1.7%), Kazbekovsky (1.6%), Babayurtovsky (1.5%), Tlyaratinsky (1.1%), Dakhadayevsky (1.04%), Sergokalinsky (1.02%), Novolaksky (1.0%), Shamilsky (1.0%), and in four municipalities: Makhachkala (2.0%), Izberbash (1.14%), Khasavyurt (1,1%) and Yuzhno-Sukhokumsk (1.0%). In 21 Raions and two municipalities, BLV seropositivity was below 1.0%. No BLV infected animals were detected in the Agulsky, Akhtynsky, Dokuzparinsky, Magaramkentsky, Khivsky, Suleiman-Stalsky Raions and in Derbent and Dagestanskiye Ogni municipalities. Studies of BLV prevalence in 2015–2021 demonstrated that the highest level of the animal infection was reported in 2015 (13.9%) and the lowest – in 2021 (1.0%). However, the number of animals serologically tested in 2021 exceeded the number of animals tested over the whole study period. Therefore, the Republic of Dagestan remains BL infected region.