Vol. 9, Issue 11, Part A (2025)

Babesiosis is a tick borne infectious disease caused by haemoprotozoan of genus Babesia. Occurrence of babesiosis is associated with the increased activity of the ticks during autumn and summer season. A carcass of one year old heifer was presented for necropsy examination at postmortem facility, division of pathology, Indian Veterinary Research Institute with the history of dullness, high fever, tick infestation, and abnormal gait. All the visible mucus membrane were pale and yellowish discoloration of fascia was observed. Prescapular lymph nodes were enlarged and edematous and the cortical area had haemorrhages. Pericardial cavity was filled with about 20-30 ml of yellowish brown fluid and severe suffusive haemorrhages were seen in the endocardium of right ventricle. Anteroventral lobes of both the lungs were severely congested with patchy area of consolidation. Peritoneal cavity was filled with about 100-150 ml of straw colour fluid. Liver and spleen were enlarged and gall bladder was distended with about 60-80 ml of dark viscid yellowish-green bile. Brain showed cherry red discolouration with congested cerebral blood vessels. Urinary bladder was distended with about 80-100 ml reddish brown urine. Centrifugation of urine at 1500 rpm for 10 min revealed red coloured supernatant with no precipitate indicating haemoglobinuria. Microscopic examination of Giemsa stained blood smear from the peripheral blood vessels revealed piroplasm of babesia in more than 10-20% of RBCs under oil immersion. Histopathological examination of the lungs tissues revealed vascular congestion and alveolar edema alongwith desquamation of the bronchiolar epithelium. Heart showed myocardial degeneration and congested myocardial blood vessels. Centrilobular necrosis was seen in the liver and the sinusoids were dilated. Mild to moderate lymphoid depletion was seen in the lymph nodes and spleen. Severe tubular degeneration was seen in the kidney with medullary congestion and renal tubules were filled with eosinophilic homogenous fluid. Cerebral vessels were severely congested and satellitosis and neuronophagia was seen in the grey matter. Hemosiderin pigment accumulation was observed in Hematoxylin & Eosin stained. Tissue sections of liver, spleen, lymph node and lungs revealed brownish granular deposit of hemosiderin, which on Pearl’s prussian blue staining were observed as bluish deposits. Microscopic examination of the tissues revealed piroplasms within erythrocytes in blood capillaries in the sections of lymph nodes and cerebrum. Based on the gross and microscopic examination the case was diagnosed as babesiosis. Babesia is associated with destruction of erythrocytes leading to hypoxia, anoxia and death.