Case report

Attempted Treatment of a Cow with Mycobacterium paratuberculosis Enterocolitis

Abstract

A Holstein-Friesian dairy cow naturally infected with Mycobacterium paratuberculosis, and suffering from enterocolitis, was treated orally with a combination of rifampin, pyrazinamide and streptomycin (30, 50 and 25 mg/kg/day, respectively) for seven months. Clinical and hematological evaluations were regularly performed beginning on the day of admission, extending throughout treatment and continuing until four months after therapy was terminated. Therapy was associated with normalization of hematological and serum biochemical parameters, and a 440 lb (200 kg) weight gain. This positive effect was observed during the entire treatment period and persisted for nearly four months after the end of therapy. Microscopic examination of Ziehl-Neelsen stained fecal samples was negative for M. paratuberculosis from the second day, and remained negative until the fourth month after therapy was completed. Fecal cultures remained positive for M. paratuberculosis throughout the observation period. The cow was harvested four months after cessation of therapy. These observations suggest that chemotherapy results in improvement in clinical signs, and might induce a transient reduction of Mycobacterium paratuberculosis shedding. It did not eradicate the infection or eliminate shedding of the organism.