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

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.

1. Aida Y., Okada K. Amanuma H. Phenotype and ontogeny of cells carrying a tumour-associated antigen that is expressed on bovine leukemia virus-induced lymphosarcoma. Cancer Res. 1993; 53 (2): 429–437. PMID: 8380256.

2. Wu D., Takahashi K., Murakami K., Tani K., Koguchi A., Asahina M., et al. B-1a, B-1b and conventional B cell lymphoma from enzootic bovine leukosis. Vet. Immunol. Immunopathol. 1996; 55 (1–3): 63–72. DOI: 10.1016/s0165-2427(96)05631-0.

3. Mirsky M. L., Olmstead C. A., Da Y., Lewin H. A. The prevalence of proviral bovine leukemia virus in peripheral blood mononuclear cells at two subclinical stages of infection. J. Virol. 1996; 70 (4): 2178–2183. DOI: 10.1128/JVI.70.4.2178-2183.1996.

4. Nekoei S., Hafshejani T. T., Doosti A., Khamesipour F. Molecular detection of bovine leukemia virus in peripheral blood of Iranian cattle, camel and sheep. Pol. J. Vet. Sci. 2015; 18 (4): 703–707. DOI: 10.1515/pjvs2015-0091.

5. Mustafaev A. R. Specificity of bovine leukemia virus depending on the breed, age and type of animal. Veterinaria i kormlenie. 2020; 4: 42–44. DOI: 10.30917/ATT-VK-1814-9588-2020-4-15. (in Russian)

6. Gillet N., Florins A., Boxus M., Burteau C., Nigro A., Vandermeers F., et al. Mechanisms of leukemogenesis induced by bovine leukemia virus: pros pects for novel anti-retroviral therapies in human. Retrovirology. 2007; 4:18. DOI: 10.1186/1742-4690-4-18.

7. Gulyukin M., Barabanov I., Ivanova L., Stepanova T., Kozireva N., Simonian G., et al. Monitoring of epidemiologic situation with bovine leukemia in production and breeding herds of Russian Federation in 2014–2015. Veterinaria i kormlenie. 2016; 4: 5–41. eLIBRARY ID: 26383305. Available at: http://vetkorm.ru/magasines/veterinariya-i-kormlenie-4-ijul-avgust-2016g/. (in Russian)

8. Makarov V. V., Lozovoy D. A. Epizootological features of modern cattle leukemia. Vestnik of the Russian Agricultural Sciences. 2020; 1: 53–58. DOI: 10.30850/vrsn/2020/1/53-58 (in Russian)

9. Mischenko V. A., Petrova O. N., Karaulov A. K., Mischenko A. V. The problem of bovine leukemia. Vladimir: FGBI “ARRIAH”; 2018. 38 p. Available at: http://www.arriah.ru/sites/default/files/private/books/problema-leykoza-krupnogo-rogatogo-skota-va-mishchenko-petrova-ak-karaulov-av-mishchenko-2018/problema_leykoza_pechat.pdf. (in Russian)

10. Mustafaev A. R. The comparative analysis of spread of the leukosis of cattle in the Republic of Dagestan. Veterinarnyj Vrach. 2019; 2: 25–30. DOI: 10.33632/1998-698X.2019-2-25-30. (in Russian)

11. Methodical instructions for diagnosis of bovine leucosis [Metodicheskie ukazaniya po diagnostike lejkoza krupnogo rogatogo skota]: approved by Veterinary Department of the RF Ministry of Agriculture on August 23, 2000 No. 13-7-2/2130. Available at: http://docs.cntd.ru/document/1200118749. (in Russian)

12. Methodical instructions for epidemiological study of bovine leucosis [Metodicheskie rekomendacii po epizootologicheskomu issledovaniyu pri lejkoze krupnogo rogatogo skota]: approved by Academician A. M. Smirnov, Veterinary Medicine Department of the Russian Academy of Agricultural Sciences, on June 19, 2001. М., 2001. 28 p. (in Russian)

13. Mustafaev A. R., Gulyukin M. I., Gaydarbekova Kh. M. The analysis of the epizootic situation of the virus of cattle leukosis in the Republic of Dagestan. Veterinaria i kormlenie. 2017; 5: 25–27. eLIBRARY ID: 30352854. Available at: http://vetkorm.ru/magasines/veterinariya-i-kormlenie-5-sentyabr-oktyabr-2017g/. (in Russian)