Systemic aspergillosis in a foals- Equus caballus

Abstract

The Aspergillus genus comprises globally distributed species of saprotrophic fungi, with the Aspergillus section Fumigatus known to cause diseases in humans and immunocompromised animals. Clinical signs depend on the affected system, exhibiting mild fever, severe colic, pneumonia, guttural bag mycosis and occasionally lesions in the central nervous system. The present work aims to report the clinical signs, necropsy findings and histology of a case of systemic aspergillosis in an eight-months-old foal. The animal had enterogastric reflux, increased peristalsis, pasty feces, abdominal pain and severe dehydration. The condition evolved to death and the cadaver was sent for necropsy. Macroscopically, there were suffusions and ecchymosis in the serosa of the gastrointestinal tract and ulcerations in the mucosa of the small intestines. In the lung, there were multifocal, whitish and firm nodules that were cystic when cut with a friable winey internal lining. The heart had whitish multifocal areas in the myocardium and the kidneys contained reddish nodules in the cortical and medullary regions. In the brain there were yellowish and hemorrhagic multifocal areas with reddish borders. Microscopically, multifocal areas of necrosis with granulomatous inflammatory infiltrate were observed in the intestine, lung, brain, myocardium and kidneys. Intralesional and intravascular fungal were observed in the brain and lung. Structures with phenotype compatible with Aspergillus fumigatus were observed in the fungal culture. In virology, samples were positive for equine herpesvirus (HVE) types 1 and 4. The diagnosis of systemic aspergillosis was determined due to the clinical history, immunosuppression, macroscopic and histological findings, fungal isolation and concomitant HVE infection.