Granulomatous lesions in multiple organs in a horse caused by Halicephalobus gingivalis

Abstract

The present report describes the clinical, macroscopic and histologic findings associated with Halicephalobus gingivalis infection in a male Arab horse, in the state of Minas Gerais, Brazil. The animal presented with acute neurologic signs that quickly progressed to a comatose status. Due to the lack of response to therapy, rapid progression of signs and poor prognosis, the horse was euthanized. Post-mortem examination revealed large granulomatous nodules in the kidneys. Renal and internal iliac lymph nodes were enlarged and with loss of corticomedullary distinction. Histopathology revealed granulomatous encephalitis, nephritis, lymphadenitis and focal granulomatous pneumonia associated with marked and chronic infection caused by H. gingivalis. This is the first report of H. gingivalis infection in horses in Minas Gerais. H. gingivalis infection should be included in the list of differential diagnosis of equine neurologic diseases in the state of Minas Gerais.