Pathomolecular Diagnosis of Tropical Theileriosis in a Crossbred Cattle

Abstract

A Holstein Friesen cattle aged 2 years with a history of high fever (107°C) was presented to the clinics of GADVASU. Hematology revealed anaemia and neutrophilic leukocytosis with mild left shift along with piroplasms suspected to be of Theileria in RBCs. Lymph node smears also revealed Koch blue bodies in lymphocytes. The cattle later succumbed and was presented for necropsy in the Department of Veterinary Pathology, COVS, GADVASU, Ludhiana. At necropsy, pale mucus membranes, icterus and multiple foci on liver were observed. Abomasum showed typical multifocal necrotic bleeding ulcers. There was also splenomegaly, enlarged lymph node and hepatomegaly. For further investigation, heart blood and spleen tissue was collected for PCR. On histopathological examination, mucosal surface of abomasum showed discontinuity with infiltration of inflammatory cells suggestive of ulcers. Spleen showed lymphoid deletion. Marked congestion along with neutrophilic infiltration was observed in lymph node whereas liver revealed loss of hepatic cord pattern along with marked hepatocytic degeneration and moderate cytoplasmic vacuolation in peri portal areas. DNA was extracted from clotted blood of heart and spleen tissue. PCR performed by using published primers with sequence Tann N516F: 5’GTA ACC TTT AAA AAC GT 3’ and Tann N517R: 5’GTT ACG AAC ATG GGT TT 3’ confirmed the presence of Theileria annulate.