Although the condition is traditionally associated with mud coating the legs, many horses go through the whole winter in muddy fields without developing any signs. The conclusion is that it is not mud but constant wetting of the skin that is the main cause. Mud fever is also often rife in yards where the legs are washed frequently, and virtually absent from yards where the legs are almost never washed. It is always better to leave the mud to dry naturally on the legs (leg wraps or bandages applied over the mud will ‘wick’ away the moisture) and then brush off the next day.
Waterproofing the lower limbs, the heels especially, before exercise or turn out is good practice. Thick creams such as zinc and castor oil cream, ‘Sudocrem’ or proprietary barrier creams are effective. Udder cream although popular is a bit too thin and hence not very long lasting.
Leaving the lower legs unclipped does little to prevent the problem. Indeed mud fever may be more common in horses with hairier legs, due in part to the longer time these take to dry out and to the difficulty in spotting early lesions. If the legs must be washed then they must be dried also. Sulphur powder sprinkled generously on the heels is very effective (even when sprinkled on wet legs) this is probably due to the fact that they have a marked drying effect.
Get into the habit of running your fingers upwards against the direction of the hair at the back of the pastern every few days to detect the very small scabs indicating an early problem. if treated immediately these small lesions will respond very quickly.
What Is Summer Mud Fever (Leukocytoclastic vasculitis)
Very similar in appearance to mud fever, this condition occurs in hot dry conditions. It is believed to be an interaction between sunlight and blood vessels in the skin, although it is not true photosensitisation. The same horses are affected year after year.
Preventing Summer Mud Fever
Protect the white lower limbs by one of the following:
- Keeping the horse indoors during the day in a sunlight free stable
- Applying high-protection factor (at least factor 30) waterproof sun block daily to the white parts of the limbs applying stable bandages from the coronet to below the knee or hock
- Using gaiter-type boots designed to be worn for mud fever prevention. These must extend from the coronet to below the knee hock.