Topical treatment using amphotericin b and dmso for an atypically located equine cutaneous Pythiosis / Pitiose cutânea equina de localização atípica tratada topicamente com solução de anfotericina B e DMSO

ABSTRACT

Background: Cutaneous lesions by Pythium insidiosum infection are commonly observed in horses, especially in those living at fl ooded environments. Equine pythiosis is characterized by the development of tumoral masses that are frequently located at distal limbs, ventral abdômen, thorax, breast and face. The lesions are usually granulomatous, serosanguineous and ulcerated, most often destroyed by self-mutilation due to the intense pruritus. The proposed treatment includes surgical excision followed by antifungal drugs administration, which can be done systemically or topically. Amphotericin B and dimethyl sulfoxide (DMSO) in association has been successfully used for cutaneous pythiosis topical treatment due to the DMSO property to carry any substance through plasmatic membranes.Case The present report concerns a 12-year-old mixed breed gelding presenting with self-mutilation of a tumoral mass located at the left fl ank. The owners reported that the horse had initially presented a small wound that had evolved to a 20-cm in diameter mass in 4 weeks. Tissue samples were collected, processed and stained by the Gomoris methenamine silver (GMS) method. The histopathological analysis revealed Pythium insidiosum hyphae in a granulomatous tissue, especially located at peripheral region, where kunkers were present. Surgical excision of the mass followed by cauterization was indicated

RESUMO

Background: Cutaneous lesions by Pythium insidiosum infection are commonly observed in horses, especially in those living at fl ooded environments. Equine pythiosis is characterized by the development of tumoral masses that are frequently located at distal limbs, ventral abdômen, thorax, breast and face. The lesions are usually granulomatous, serosanguineous and ulcerated, most often destroyed by self-mutilation due to the intense pruritus. The proposed treatment includes surgical excision followed by antifungal drugs administration, which can be done systemically or topically. Amphotericin B and dimethyl sulfoxide (DMSO) in association has been successfully used for cutaneous pythiosis topical treatment due to the DMSO property to carry any substance through plasmatic membranes.Case The present report concerns a 12-year-old mixed breed gelding presenting with self-mutilation of a tumoral mass located at the left fl ank. The owners reported that the horse had initially presented a small wound that had evolved to a 20-cm in diameter mass in 4 weeks. Tissue samples were collected, processed and stained by the Gomoris methenamine silver (GMS) method. The histopathological analysis revealed Pythium insidiosum hyphae in a granulomatous tissue, especially located at peripheral region, where kunkers were present. Surgical excision of the mass followed by cauterization was indicated