Mud Fever is common in wet weather and treatment is not simple. Removing the horse from the mud will obviously improve matters, even though that is not always easy or possible. If your horse has to be turned out, do not rely on barrier creams as protection against mud fever; they should be used with caution as they provide a suitable environment for bacteria to grow between the waterlogged skin and the greasy layers applied on top.
It will help if you can allow an affected horse some time to stand in a dry stable each day. If your horse has wet and muddy legs when you bring him in, try to allow them to dry thoroughly, then brush off the mud. A dry shavings bed helps to absorb moisture from waterlogged limbs. Sand schools can irritate the skin further, as can scrubbing with stiff brushes and excessive washing to remove mud. All these cause tiny scratches allowing bacteria to invade. If you are riding and want to wash the legs off to put boots on you can use warm water with dilute chlorhexidine (hibiscrub) and dry the legs thoroughly afterwards. Clean towels or kitchen roll can also help to remove excess moisture and drying leg wraps that wick moisture away from wet skin are beneficial too.
It is WRONG to assume that bacteria cause all these pastern problems, so antibiotics are not necessarily the answer, instead they should be saved for the worst-case scenarios. Think carefully before considering antimicrobials for the horse with scabby legs, as it is unlikely to produce a permanent cure and it may not help at all, as well increasing the potential for antibiotic resistance. If there is a management improvement that you can make, try that first.
Some horses with pastern dermatitis will be suffering from infestations of tiny mites, (chorioptic mange mites), similar to those causing scabies in man. This is commonest in horses with long hair (so-called feathers) around their lower limbs, but can occur in horses with less hairy legs. It is often called heel mange. Fungal infections can also be responsible for skin damage. Neither mites nor fungal infections will resolve with antibiotics, which is one of many reasons why they do not always cure the condition.
Another form of pastern inflammation is caused by a disorder of the body’s immune system, which attacks the skin. This is known as leucocytoclastic vasculitis, which targets the unpigmented areas of the lower limbs. It tends to spread up the cannon and as it is usually seen on the outside and back of the limb, sunlight is thought to aggravate it. This condition is a problem in both summer and winter and no amount of creams, lotions or antibiotics will control it. High doses of steroids that diminish the damaging inflammation are the only effective cure and will be prescribed by your vet, when necessary.
You will know if your horse’s pastern dermatitis has bacteria involved because the skin appears red and sore like impetigo, which is a fairly common human skin rash. When a scab is picked off, the hair will come away with it revealing a raw area with pus beneath it. Views vary, but generally once this occurs, the legs need careful cleaning and the scabs may need to come off.
If you would like more information or to discuss the best treatment for your horse, please call BELL EQUINE on 01622 813700 and ask to speak to one of our vets.