Vol. 9, Issue 3, Part C (2025)

Babesiosis is a significant disease affecting yaks and yak-cattle hybrids, caused by Babesia bigemina. Present study reports a case of Babesiosis in a 5-year-old female yak. The yak showed symptoms of loss of appetite, lethargy, no milk secretion, high fever exceeding 104°F and brown-colored urine. Blood sample was collected for microscopic examination and detection of Babesia spp. polymerase chain reaction (PCR). On the basis of the clinical presentation, the yak was promptly treated for Babesiosis with Berenil (3.5 mg/kg body weight) and ivermectin (200 mcg/kg body weight), however the animal died the next day. Post-mortem examination revealed pale and icteric mucous membranes, watery blood, an enlarged icteric liver with a distended gallbladder, and a markedly friable and enlarged spleen. The kidneys appeared black, and the urinary bladder contained brown-colored urine. Microscopic examination of Giemsa-stained blood smears revealed the presence of Babesia sp., which was further confirmed using polymerase chain reaction (PCR) with B. bigemina-specific primers.