Investigation of Anaplasma marginale, Babesia bovis, Babesia bigemina and Trypanosoma vivax in the brain and spleen of dairy cows of Rio Grande do Sul

Cattle tick fever and bovine trypanosomosis are diseases that negatively impact cattle production in Brazil, causing considerably productive losses and animals death. In this study, the objective was to investigate the presence of the four hemoparasites that mostly affect dairy herds (A. marginale, B. bovis, B. bigemina and T. vivax) using the qPCR technique in discarded dairy cows in the northwestern region of Rio Grande do Sul. For this purpose, brain and spleen tissue biopsies were collected at a local slaughterhouse from 64 dairy cattle from this region. DNA extraction from the samples was performed using the Brazol® reagent, their quantity and purity were obtained through spectrophotometer analysis with NanoDropTM. In the brain samples, DNA detection was performed for T. vivax and B. bovis, and in the spleen, DNA of the four agents was verified. From a total of 64 brain samples analyzed, 14.06 % were positive for Babesia bovis. For spleen samples, Babesia bovis was detected in 17.19 % of the samples, while 29.69 % tested positive for B. bigemina and 37.50 % for Anaplasma marginale. Regarding Trypanosoma vivax, none of the analyzed samples resulted in a positive diagnosis in both tissues. Thus, the findings highlighted that B. bovis, B. bigemina and A. marginale are present in the dairy cattle herd of the northwestern regions of Rio Grande do Sul, with a higher percentage of A. marginale; on the other hand, T. vivax was not diagnosed in the present study.