Ovine rhinofacial pythiosis - A case report

Pythiosis is an emerging infectious disease caused by the aquatic oomycete Pythium insidiosum, a fungal-like organism. The present report highlights the pathomorphological features of pythiosis recorded in the nasal cavity of a 2-year-old female non-descriptive sheep presented to the Veterinary Clinical Complex, Rajiv Gandhi Institute of Veterinary Education and Research, Puducherry, India. Clinical examination revealed serosanguineous nasal discharge from the left nostril and a growth which was intact with the maxillary bone. Incisional biopsy sample fixed in 10% neutral buffered formalin was processed by routine paraffin embedding technique and sections stained with H&E. Histopathological examination revealed a characteristic pyogranuloma with central amorphous eosinophilic area surrounded by neutrophils, degranulated eosinophils and karyorrhectic debris. Gomori methenamine silver staining revealed thin-walled, non-parallel and sparsely-septate hyphae with ballooning dilations. Based on the clinical signs, histopathology and histochemistry the case was diagnosed as ovine rhinofacial pythiosis.