Samples from intestines, liver, and lymph nodes were collected from a dairy steer with clinical suspicion of paratuberculosis. The samples were processed for histologic examination with hematoxylin-eosin and Zihel-Neelsen (ZN) staining for the detection of acid-fast bacilli (AFB), and submitted to immunohistochemistry (IHC). Macroscopic changes were observed in the small intestines, with thickening and corrugation of the mucosa. The main microscopic changes were found in small intestines, lymph vessels in the mesentery, and mesenteric lymph nodes characterized by enteritis, lymphangiectasia, and lymphadenitis. Liver presented with granulomatous hepatitis, an uncommon histopathological feature for paratuberculosis. The clinical features associated with positive culture of Mycobacterium avium subsp. paratuberculosis and detection of AFB by ZN and IHC in the cytoplasm of macrophages (epithelioid) in the intestinal mucosa and submucosa, lymph nodes, and liver were important to confirm the diagnosis of paratuberculosis.

O estudo se propõe a avaliar a etiologia e a susceptibilidade de estafilococos isolados de cães com dermatite. Os isolados foram identificados por provas bioquímicas e testados quanto a sua susceptibilidade a 15 antimicrobianos. Trinta e nove isolados de Staphylococci foram obtidos, e S. pseudintermedius foi mais freqüente (47,4%). Todos isolados apresentaram resistência a pelo menos uma droga e 77,1% foram multirresistentes. A oxacilina foi a droga mais eficaz. O estudo demonstra níveis alarmantes de resistência antimicrobiana nos Staphylococcus de pioderma canino.

The study aimed to determine the etiology and antimicrobial resistance of staphylococci isolated from canine pyoderma. Samples were obtained from dogs with pyoderma and isolates were identified by biochemical reactions and tested for susceptibility to 15 antimicrobials. Thirty nine staphylococci isolates were obtained, and S. pseudintermedius was the most frequent (47.4%). All isolates showed resistance to at least one drug and 77.1% were multiresistant. The most effective drug was oxacillin. The study reports the alarming antimicrobial resistance of Staphylococcus isolated from canine pyoderma samples.