With all this wet weather we have been having recently making for muddy conditions, our equine vet Saara says we should be on the look-out for mud fever. “Mud Fever” is always multifactorial, but the wet conditions cause the skin to soften and mud rubs against this softened skin causing damage to the surface where bacteria can enter. It is a non-contagious skin condition that causes irritation, soreness, and matted areas of hair with scabs that form on the horse’s lower legs. You may also hear it referred to by a few other names, including dermatitis, greasy heels, and cracked heels. Mud fever commonly forms on the pastern and the heel. Infections can develop underneath the scabs, and you may see swelling of the leg in severe cases. Mud fever can be painful, and the horse may not tolerate the area being touched.
- Trauma due to wounds, overreaching and incorrectly fitted boots.
- Ectoparasites such as mites which break the skin and enable bacteria to enter. Horses with feathers are more at risk of leg mites and you will see them stamp their legs because they’re very itchy.
- Standing in deep mud or wet bedding for long periods.
- Excessive washing and scrubbing of muddy legs.
- Having a weakened immune system – which is usually secondary to another condition, such as Cushings Disease. Horses with a lowered immune system are less able to prevent and fight off infections, so are more prone to other health conditions. If these horses suffer from mud fever, it can be more difficult to treat.
- White legs – pink skin under white markings is often more sensitive.
- Thin skinned horses such as Thoroughbreds or Arabs, which can be damaged more easily, giving bacteria a way in.
- Classically, early or mild lesions present with redness and loss of hair in the pastern region, but can extend up the cannon, often with just hair loss. More chronic cases may show crusty scabs, ulceration, oozing or thickened skin.
- Broken or damaged skin.
- Matted hair or patches of hair loss with raw skin underneath.
- A creamy white, yellow, or green discharge between the skin and the scabs.
- Heat, pain and swelling in the lower leg.
If left untreated, mud fever can cause cellulitis, chronic infection, and inflammation of the soft tissues. This can in turn lead to filling of the lower limb, with heat and pain, occasionally extending above the hock. At this stage horses present with lameness and may not bear weight on the affected leg, and definitely needs antibiotic treatment.
Treating Mud Fever
Saara says if you see any signs of mud fever to call and ask for an appointment so that she can give you an accurate diagnosis.
A typical treatment plan should include:
- Ideally, bringing your horse in out of the wet and muddy field and stable on dry, clean bedding. But regular movement and exercise is very important to prevent or disperse any filling of the legs.
- Very gently remove the scabs to help apply treatment and to allow air to reach the skin but take care not to cause further trauma- it is extremely easy to become over-enthusiastic and make the horse sore.
- Clean the affected area daily by cold hosing and drying with a clean towel. Use very dilute hibiscrub or a soothing antibacterial shampoo approximately 2-3 times weekly, as daily may be too aggressive for the horses’ skin. After drying, a very thin layer of antibacterial may be applied. Saara will be happy to advise you.
- Clipping the feathers is recommended in order to clean the wounds, keep the skin dry, apply the cream and to monitor the healing process. All the micro-organisms involved in mud fever are microaerophilic, meaning they don’t like oxygen, so clipping is extremely helpful.
- Very severe cases where the leg is swollen and painful require antibiotics in the feed or as injections.
Preventing Mud Fever
Saara says that there are many ways to reduce the risk of your horse developing mud fever. However, not all treatments, or preventatives, work for every horse, so it is most important to find what works for you and your horse.
- Try to avoid turning horses out in very muddy fields. If you use turnout boots make sure they fit correctly, and allow the skin, and boots, to dry thoroughly between uses.
- Some horses are better if recurrent wetting and washing is avoided- these individuals respond better if the mud is allowed to dry and then brushed off. Other horses are better hosed off and dried daily. This is very individual to the horse, and the management system.
- You can use barrier cream, or good old pig-oil, prior to turn out, but keep all applications as thin as possible- remember microorganisms are microaerophilic! (see above)
- Sand schools can irritate the skin and washing to remove the sand might be necessary.
- Check your horses’ legs every day to spot problems as early as possible.
If you have any concerns regarding your horse or pony, please call us.