Aspectos epidemiológicos e patológicos de salmonelose em bovinos no Sul do Brasil

EnglishSalmonellosis is a bacterial disease that affects several domestic animal species, and is commonly diagnosed in cattle, horses, and pigs. This study aimed to describe the epidemiological and pathological findings of eleven cases of enteric salmonellosis and two cases of salmonellosis with pulmonary involvement in cattle in Rio Grande do Sul State, Brazil. Clinical signs included fever, yellow diarrhea, sometimes with blood streaks, and dyspnea, with a clinical course ranging from 1 to 30 days. Eight cases occurred as outbreaks, whereas five cases occurred individually. Risk factors included inadequate handling practices, such as overcrowded facilities and comorbidities, including anaplasmosis. The main gross finding of the enteric presentation was fibrinonecrotic enterocolitis, occasionally associated with button ulcers, mesenteric lymphadenomegaly, splenomegaly, cholecystitis and hepatomegaly. In addition, one steer with a chronic clinical progression presented severe segmental thickening of the ileum, associated with intestinal rupture and peritonitis. In the respiratory system, the main findings were reddened, non-collapsed lungs, with multifocal areas of atelectasis. The main microscopic findings were observed in the small and large intestines, and these were characterized by severe necrosis and mucosal ulceration, associated with marked inflammatory infiltrate of neutrophils and fibrin deposition intermixed by rod-shaped bacterial aggregates, and fibrosis, as well as interstitial pneumonia. Seven cases yielded positive bacterial cultures for Salmonella spp. and three serovars, namely Typhimurium, Dublin, and Panama were identified. All cases exhibited immunolabeling for Salmonella spp. using immunohistochemistry portuguesSalmonelose e uma doenca bacteriana que afeta inumeras especies animais, especialmente os bovinos, os equinos e os suinos. O presente estudo teve como objetivo descrever os aspectos epidemiologicos e patologicos de onze casos de salmonelose enterica e dois de salmonelose pulmonar em bovinos no estado do Rio Grande do Sul, Brasil. Os sinais clinicos incluiram febre, diarreia amarelada, por vezes com estrias de sangue, anorexia, perda de peso e dispneia, com curso clinico que variou de um a 30 dias. Em oito casos, a doenca ocorreu em forma de surtos e cinco foram individuais. Identificou-se fatores de risco relacionados ao manejo inadequado com os bovinos, como alta lotacao, alem de comorbidades associadas, como anaplasmose. Os principais achados macroscopicos da forma enterica consistiram em enterocolite fibrinonecrotica, por vezes associada a formacao de ulceras botonosas, linfonodos mesentericos e baco aumentados, colecistite e hepatomegalia. Ainda, um bovino com quadro clinico cronico apresentou acentuado espessamento segmentar da parede do ileo associado a ruptura intestinal e peritonite. Na forma respiratoria, os principais achados incluiram pulmoes nao colabados, avermelhados, com areas multifocais de atelectasia. Os principais achados microscopicos foram observados no intestino delgado e grosso e foram caracterizados por acentuada necrose e ulceracao da mucosa, associada a acentuado infiltrado inflamatorio de neutrofilos e deposicao de fibrina entremeada por agregados bacterianos cocobacilares e fibrose, alem de pneumonia intersticial. Sete casos foram positivos para Salmonella sp. no cultivo bacteriano, com identificacao dos sorovares Typhimurium, Dublin e Panama. Ao exame imuno-histoquimico para Salmonella sp. todos os casos apresentaram marcacao positiva nos orgaos avaliados