Mud fever (pastern dermatitis) is a painful skin condition in horses caused by prolonged wet and muddy conditions, causing lameness and significant welfare harm during wet seasons.
Mud fever causes a specific type of chronic, low-level welfare harm that accumulates through wet seasons. Affected horses experience persistent skin pain and discomfort with every step. Because the condition develops gradually and horses often mask early discomfort, owners may not intervene until lameness has already developed. The welfare challenge is primarily one of recognition and prevention — maintaining dry standing areas, managing pasture sacrifice areas, and regular leg inspection in wet conditions. Treating active cases requires patience and compliance as scab removal and daily cleaning are themselves uncomfortable procedures.