Melanomas affect the vast majority of grey horses as they age, but proactive monitoring and strategic management can maintain good quality of life for affected horses through their senior years.
Grey horse melanoma welfare management is fundamentally about informed monitoring combined with strategic intervention at appropriate thresholds. The majority of affected horses live comfortably for many years with slow-growing tumors that require only monitoring. The welfare-critical decisions arise when tumors grow to affect comfort or function at sensitive sites - under the tail affecting defecation, at the eyelid affecting vision, or at the parotid affecting swallowing. Early surgical intervention at these sites, before tumors become too large for complete excision, prevents the welfare deterioration that occurs when tumors restrict normal function. Establishing baseline documentation from early in a grey horse's life enables objective assessment of change rate and informs treatment timing decisions.