Mud fever (pastern dermatitis) causes painful skin lesions on horse legs from prolonged wet conditions and is a common but preventable welfare problem in wet climates.
Mud fever causes genuine discomfort and pain in affected horses, with lesions that are sensitive to touch and can progress to lameness if untreated. The welfare challenge is that treatment — which requires removing scabs to allow medication to reach the skin beneath — is itself painful and resisted by horses. Early detection and treatment, before lesions become established and extensive, is both less painful and more effective. Prevention through pasture management is preferable: improving drainage, providing dry turnout areas, and avoiding excessive leg washing that removes protective skin oils significantly reduces incidence. Horses prone to mud fever due to pink skin or feathered legs require closer monitoring and earlier intervention during wet seasons. The welfare-centered approach is prevention first, early detection second, and prompt, appropriately analgized treatment when lesions develop.