Mycobacteriosis in domestic dogs. Report of two cases in São Paulo, Brazil

Abstract

In veterinary dermatology, domestic carnivores sporadically are found with ulcerated lesions characterized by a prolonged course of evolution and by relative unresponsiveness to the usual drug therapy; this condition can be due to infections caused by microorganisms of the Genus Mycobacterium. Due to the scarcity of its description in Brazilian literature, and due to the inusitate lesions and response to preconized therapy, two cases of canine mycobacteriosis attended at the University Veterinary Teaching Hospital of the FMVZ/USP are then described. The adult bitches (German Shepherd and Doberman Pinscher) were found with ulcerated lesions at the posterior side of the pinna w ith granulomatous aspect and with exudation and covered by hemorrhagic crusts without showing any detectable satellite lymphadenomegalia or any symptoms in other systemic organs. Physical, hematologic and radiographic examinations were performed and lesions have been curetted and biopsied through punching technique, and specimens were examined histologically using Holst-Mitchinson and Radhakrishna and Ziehl-Neelsen staining, and throught culture methods using Lowenstein-Jensen and Stonebrink & Leslie media at different temperature of incubation. Intradermal tuberculin test using PPD tuberculin of mammalian and avian origin were performed. Presence of alcohol-acid resistant bacilli were detected throught histopathologic examination. The growth of bacilli, however, were not confirmed by the use of conventional media, even being incubated at different temperatures, although found with typical pyogranulomatous tissue reactions. After introducing the topical therapy, represented by the Domeboro’s solution, rifamycin. and parenteral use of rifampicin, lesions showed marked remission. Etiology, pathogeny and other diagnostic and therapeutic maneuvers are also discussed.