Survey of Cutaneous Neoplastic and Nonneoplastic Lesions of Horses From Central-West Brazil

A retrospective study was designed to determine the occurrence of cutaneous neoplastic and nonneoplastic lesions in horses from Central-West Brazil by examining the hospital records of horses submitted for biopsy at the Universidade de Cuiabá, Mato Grosso, during January 1998 to December 2013. During this 15-year period, biopsy specimens of 133 horses were received for histopathological diagnosis; most of these (69.9%; 93/133) were cutaneous biopsies. No significant difference was observed between the genders of horses with a cutaneous diagnosis; 51.6% (44/93) were males, 47.3% (44/93) females, and the sex of one animal was unspecified. Mixed-breed horses were predominant (35.3%; 33/93), followed by the Quarter Horse and Pantaneiro breeds (25.8%; 24/93). A definite seasonal pattern relative to the occurrence of cutaneous disease was not observed. Cutaneous diseases were more frequent in horses that were more than 1 year of age. Nonneoplastic cutaneous lesions (73.1%; 68/93) were more predominantly diagnosed relative to neoplastic disease (19.4%; 18/93). Pythiosis was the most frequent (50%; 34/68) nonneoplastic lesion and represented 36.5% (34/93) of all cutaneous lesions diagnosed. Squamous cell carcinomas (44.4%; 8/18) and sarcoids (38.9%; 7/18) were the most frequently diagnosed neoplastic lesions. These findings suggest that cutaneous lesions are common in horses from the Central-West region of Brazil, and the age, gender, and breed per se of the affected horse were not determinant factors relative to the occurrence of skin lesions in horses from this geographical region.