Source: Texas A&M University

While many skin lumps on horses are harmless, others may be cancerous and require prompt veterinary care, says Dr. Leslie Easterwood of Texas A&M College of Veterinary Medicine. Common noncancerous bumps, like eosinophilic granulomas, often result from insect bites, while more serious tumors include sarcoids and squamous cell carcinomas (SCC). SCC is common in light-skinned horses and appears around sensitive areas like eyelids and lips, while sarcoids often develop in areas of prior injury or irritation.
Early detection is crucial to prevent tumor spread or complications. Treatments vary by tumor type and include photodynamic dye therapy for SCC and surgical removal with chemotherapy for sarcoids. Although skin tumors have no single cause, genetic predisposition, sun exposure, and viruses like bovine papillomavirus all play roles. Preventive steps such as fly control, regular skin checks, and sun protection can help reduce risks. Staying vigilant ensures better outcomes and keeps horses healthy and comfortable.