Salmonelose equina em Minas Gerais

Abstract

Salmonellosis is a bacterial infectious disease of worldwide importance in several species, with great zoonotic potential. Young, immunocompromised, hospitalized horses or undergoing prolonged antibiotic therapy are more susceptible to the disease. Although significant, the disease is often neglected and undiagnosed in herds. In horses, the disease is caused by S. enterica subsp enterica, with the most important serovars Salmonella Anatum, Salmonella Typhimurium, Salmonella Newport, Salmonella Enteritidis, Salmonella Heidelberg, Salmonella Arizona, Salmonella Agona and Salmonella Abortusequi. The aim of the study was to evaluate the cases of salmonellosis in horses submitted to the Veterinary Pathology Sector of UFLA, from January 2010 to March 2019, with description of the main clinical, gross, histological and epidemiological findings. Of 156 horses with concluded diagnosis, 59 (37,8%) were diagnosed with infectious disease, and of these, 19 (32,2%) had gross and histological lesions compatible with salmonellosis. Of these horses, 11 were females and eight males, whose age ranged from fifteen days to 17 years and there was variation in the management system. No seasonal variation was observed, considering the time of the year when the deaths occurred. The predominant clinical signs were diarrhea, colic and neurological signs, with sudden deaths, superacute and acute to chronic clinical presentations. The main gross findings were liquefied, fetid and dark contents in the small and large intestine, hemorrhages in the intestinal mucosa and whitish foci in the liver. Histopathology showed necrosis of the intestinal mucosa with fibrin deposition, mixed inflammatory infiltrate or composed predominantly of neutrophils, besides thrombosis submucosa vessels. In the liver, there was multifocal necrosis associated with thrombosis and a mixed inflammatory infiltrate. Gut samples of twelve of the horses with lesions compatible with salmonellosis were evaluated by immunohistochemistry using antiSalmonella spp. antibody, which confirmed the diagnosis in all the cases. The disease can exhibit high mortality rates, even with treatment. Salmonellosis has variable clinical features, according to sanitary and epidemiological factors, hindering the clinical diagnosis, so that the post mortem examination is of great importance for the diagnostic conclusion.