Winter can spark an attack of mud fever, a disease horse owners dread because it is so tricky to treat. Plenty of horses live out quite happily throughout the wettest, coldest period of the year and never show a single sign of mud fever. However, it only takes a small cut, bite, wound or rub, or a chap to form due to constant wetting and drying, and the bacterium Dermatophilus congolensis, whose spores are activated by wet weather, will take advantage of the situation and invade the body through the break in the skin (but be aware that sometimes dry, dusty conditions can cause the skin to crack, too).
Areas of the lower limbs, notably the pastern and fetlock, are particularly susceptible, and while horses with hairy legs seem less prone to mud fever, those with white skin are prime candidates for the disease.
In some cases, the horse may only develop mild irritation, but in others the scabs or sores will be painful and may become infected, sometimes leading to swelling and lameness which will necessitate a course of antibiotics.
The old adage ‘prevention is better than cure’ is particularly true in the case of mud fever. Check your horse daily for signs of any matted hair, scabbing or discharge because the sooner you spot the tell-tale signs, the easier it will be to treat the condition.
If you think you are helping your horse by regularly washing the mud off his legs, you aren’t. Avoid this and instead wait for the mud to dry and then carefully brush it off. If it is unavoidable that you wash off the mud, make sure that you dry your horse’s legs thoroughly afterwards.
If your horse has to be turned out when it’s muddy, try to ensure that he doesn’t have to stand for hours in deep mud. If you have limited grazing and turnout is essential, consider applying an oil-based cream or petroleum jelly to his legs, but only when they are clean and dry. This will act as a barrier against Dermatophilus congolensis. If your horse is stabled, keep the bedding dry and clean. Standing in deep wet straw can be as bad for him as standing in a deep muddy field.
The healthier your horse is, the less chance there is of him succumbing to mud fever. Call one of the many feed helplines that are provided by major feed manufacturers and ask them not only about a winter feeding regime but also about nutritional supplements that will help to keep his skin in tip top condition throughout the winter months.
Prevention is not only recommended to avoid the pain mud fever can cause the horse, and the potentially long-term stabling and layoff from work that may be necessary, but also because any horse that falls victim to the disease will almost always be more prone to a subsequent attack.
If all your preventative measures haven’t worked, the way to treat mud fever is to remove the scabs, wash the area with an antibacterial wash or medicated shampoo, rinse and then dry thoroughly, ideally with a hair dryer.
The next step is to apply an antibiotic cream. During the healing process, which can take weeks, more scabs may form and the whole treating cycle will need to be undertaken again — maybe several times.
The horse will probably require stabling during this time to keep him away from the mud that caused his problems in the first place. Generally, covering the affected area is not recommended as a bandage will encourage the area to remain moist and warm — a breeding ground for bacteria.
As with any condition, it is worth consulting your vets at the onset of mud fever. They will be able to advise on a treatment plan and future preventative measures. If you tackle the disease correctly from the outset, you will save your horse a lot of pain and yourself considerable time and money.