Four crossbred cows, 3-5 year- old, naturally infected with Mycobacterium avium subspecies paratuberculosis (MAP) were sacrificed and necropsied. Clinically, they showed profused diarrhoea, emaciation and rough coat with an area of alopecia on the tail. The most prominent macroscopic lesions were thickening, oedema and corrugation of the wall of small and large intestines. The mesenteric lymph nodes were enlarged and oedematous. Microscopically, all cows presented granulomatous enteritis. The inflammatory exudates varied from accumulation of lymphoid cells mixed with some epithelioid macrophages and giant cells to sheets of epithelioid macrophages intermingled with some lymphoid cells. The lymphatics in the submucosa of both the small and large intestines were dilatated and filled with pink homogenous proteinous materials. Acid-fast bacilli (AFB) were demonstrated in the infiltrating epithelioid macrophages and giant cells. Culture of inocula from the small and large intestines and the mesenteric lymph nodes of all animals showed small, round, smooth and glistening colonies 5-7 weeks following incubation in Herrold's Egg Yolk Medium at 37°C.
Pathology, Cattle, Naturally, Mycobacterium paratuberculosis, Khartoum, Sudan