What is mud fever?
Mud fever, or equine pastern dermatitis, is the term given to a bacterial skin infection (dermatophilus congolensis) that affects the horse’s lower legs, typically around the pastern and fetlock, but it can extend up the lower limb.
The same bacteria can also affect the skin on the horse’s back and flanks, but this is known as rain scald or rain rot. The bacterium that causes mud fever acts like a fungus, so it can lay dormant as spores until the conditions are right for the infection to develop. As the name suggests, it commonly affects horses when they are subjected to muddy and wet conditions, however this isn’t always the case.
Why is my horse affected?
Mud fever is caused when weakened or damaged skin allows micro-organisms to enter and cause the infection to take hold. There are several reasons for the skin becoming damaged, such as from mites, abrasive sand/soil surfaces, excessive leg washing causing the skin to weaken and crack, to also sunburn or conditions such as PPID weakening the immune system.
What are the signs?
The first sign is typically just inflammation around the infected area (often the pastern or fetlock). Sometimes redness of the skin is noticeable as a result of the acute inflammatory reaction, especially if the horse has white legs. There may be some hair loss and scabs will start to appear and will worsen as the infection develops. The affected area may look greasy, caused from serum oozing from the skin and this can progress to pus that hardens to crusts on the skin which harbours the harmful bacteria.
How can it be treated?
There are many treatments available for mud fever and there isn’t one method that works as a ‘cure all’ but essentially you need to treat any underlying issue (such as mites), and then remove the infection and allow the skin to heal. Your vet will be able to suggest the best course of treatment for your horse.
- In most cases, it is a good idea to clip the area to make treating the infection a little easier.
- As the harmful bacteria need warm, moist conditions to breed, they typically harbour under the scabs. Therefore, it is generally recommended that the scabs are gently removed by soaking them with a solution of warm water and an antibacterial skin cleanser, and then gently, but thoroughly drying the area.
- An antibacterial cream should be applied following scab removal to support healing and act as a protective barrier to any further infection. Your vet can supply a corticosteroid cream.
- It is also helpful to apply a barrier cream before turnout.
- Often a vet will advise box rest to give the skin a break from the wet and muddy conditions in the field. If your horse is stabled, ensure he has clean and dry bedding daily.
Nutritional support
Consider a supplement designed to support the skin and coat. Feedmark’s EquiDermis provides the horse with the helpful herbs Burdock root, Nettle, Clivers, Chamomile, plus Brewer’s yeast on a base of Micronized linseed and Linseed oil. This powerful combination delivers a good source of Omega-3 fatty acids and naturally occurring B vitamins to support healthy skin. The herbs have been selected as they help to soothe the skin, strengthen hair and counteract dryness. Calcium carbonate has also been added to balance the important calcium to phosphorus ratio.