Multiple Simultaneous Proliferative Lesions on the Prepuce and Penis of a Gelding

Skin lesions are among the leading diseases in equids, and the urogenital region is considered the third most frequently affected body location with tumors and tumor-like skin lesions in horses. Tumor-like skin lesions or multiple tumors of different types in the equine prepuce and penis are a challenging clinical presentation leading to misdiagnosis and subsequent ineffective treatment. An 18-year-old 395-kg male mixed-breed gelding was referred for evaluation of preputial enlargement. Clinical examination revealed a 2.5 × 2.0 × 0.8 cm proliferative ulcerated lesion on the penile mucosa, five ulcerated and circumscribed hardened wounds on the preputial skin fold from 2.0 to 6.0 cm in diameter, and multiple variable-sized raised exophytic lesions ranging from 2.0 mm to 2.3 cm cauliflower-like lesions throughout the prepuce and penis. Pathological and immunohistochemical findings confirmed the definitive diagnosis of three distinct proliferative lesions: squamous cell carcinoma, squamous viral papilloma and cutaneous habronemiasis. Additionally, we present features of concurrent habronemiasis and squamous cell carcinoma and highlight the importance of proper diagnostic approach in the prognosis and correct treatment selection.