PATHOLOGICALINVESTIGATIONOF BOVINE TUBERCULOSIS EMPHASIZED ON TUBERCU! HYPERSENSITIVITY TEST

Abstract

The study was designed to investigate the pathological conditions of bovine tuberculosis (BTB) emphasized on tuberculin hypersensitivity test in HSTU campus, Dinajpur and it’s surrounding regions during March —December, 2011. A total of 150 cattle (over the age of 6 months) were selected for tuberculin test by mammalian PPD (purified protein derivative) at caudal fold area in intradermal route regardless of sex and breed. In the present study, 5 (3.33%) out of 150 cattle showed tuberculin positive reaction (distinct and visible swelling) and 6 (4.00%) cattle showed doubtful reaction (indistinct and invisible swelling). Hematological examination showed an increase in TLC; decrease in TEC, Hb, and PCV% in tuberculin positive animals compared to negative ones and an increase in Globulin content, decrease in total serum protein and albumin in tuberculin positive animals in case of biochemical examination but was statistically insignificant. Grossly congested, consolidated localized nodular type lesions found in the lungs and small nodule found also in liver and histopathologically granulomatous nodular lesions with purple coloured necrotic mass surrounded by various reactive cells and fibrous connective tissues were found in lungs pursued by necropsy of selected tuberculin positive animal. But acid fast bacilli were not found in aspirate smears of lungs and spleen by classic Ziehl—Neelsen staining. The study dictates a positive correlation among the tuberculin hypersensitivity test, gross and histopathological study of visceral organs, hematological and biochemical examinations.