Sarcoidosis in Polo Ponies: Case Study of Argentine-Cross Breeds

Equine sarcoid is the most common tumour of horses and accounts for over half of all equine skin tumours.Six different types of sarcoids based on gross appearance and clinical behaviour have been described including occult, verrucous, nodular, fibroblastic, mixed and malevolent.Physical examination was done by the over-reaching of horse while galloping during polo games before 8-10 months ago.The history was reported for each one, in addition clinical signs with morphological and histopathological examinations.On histopathology, lesions appeared ashyperkeratosis and hyperplastic changes at the cross section of the hair follicle shaft.Cross section of rete pegs indicated characteristic of sarcoid histopathology alteration where rete pegs extended deep into the dermis.The microscopic change also showed an interlacing fibrous connective tissue with collagen pattern (red circle) and spindle shaped fibrocytes indicated characteristic histopathologic changes seen in sarcoid cases.