Squamous cell carcinoma (SCC) of the third eyelid is a locally invasive neoplasm arising from squamous epithelial cells and one of the most frequent ocular tumors in horses.
Clinical presentation may include:
• Proliferative, ulcerative, or plaque-like lesions on the third eyelid
• Redness, swelling or chronic ocular discharge
• Progressive enlargement of the third eyelid and failure to respond to routine medical therapy
Predisposing factors:
• Chronic ultraviolet (UV) light exposure
• Lack of pigmentation around the eye
• Increasing age
Diagnosis & management:
Diagnosis is based on physical examination and confirmed via histopathology. Early intervention is critical, as SCC is locally aggressive and can invade surrounding ocular structures. Treatment options may include surgical excision of the third eyelid, sometimes combined with adjunctive therapies such as cryotherapy or chemotherapy, depending on lesion size and extent.
Prognosis is significantly improved with early detection and treatment.
If you observe any persistent or progressive ocular abnormalities in your horse, contact us at Central Lakes Equine for prompt evaluation and treatment planning. Early action helps preserve ocular comfort, function, and long-term outcomes!