MUD fever, which is often referred to as cracked heels or mud rash, is a common but painful condition found on horses’ legs, where the skin becomes inflamed and scabby. Sometimes the leg may ooze a yellowish fluid and the pastern, coronet and heels of the foot may become cracked.

Mud fever is typically found in the back legs of horses, though any leg can be affected. White legs (pink skinned) are more prone to mud fever than darker coloured legs. In severe cases, the horses’ leg can swell and cause lameness.