Melanomas are extremely common in grey horses, often affecting periorbital tissues. Welfare management of this common tumor requires monitoring for welfare-impacting complications.
Most equine melanomas cause minimal welfare harm for years — many grey horses live normally with widespread melanomas throughout their lives. However, specific locations create welfare problems through compression or obstruction of vital structures. Periorbital melanomas impair eyelid movement and normal blinking, causing chronic corneal irritation, epiphora, and photosensitivity. Tumors compressing the rectum or urethra cause defecation or urination difficulties with associated welfare harm.
Monitoring for progression and welfare-impacting complications is the cornerstone of melanoma management in grey horses. Regular measurement of tumor dimensions, veterinary assessment of functional impact, and early intervention when welfare-critical locations are affected prevents the escalation of manageable to severe welfare problems.