Mud fever is a general term for a skin infection around the heels and pastern of a horse. It is also frequently called "greasy heels or "cracked heels" and is caused by an infectious agent called dermatophilus congolensis, which loves muddy wet conditions.
The infection can stay dormant in the skin, becoming active when the skin is compromised in some way, usually by prolonged wetting. Spores germinate to produce hyphae (threadlike tentacles) that penetrate into the living skin and spread in all directions from the original site. The result is an acute inflammatory reaction.
Often the disease is made worse by a secondary infection. Classically there will be serum oozing from the skin, causing the hairs to stick together. There are often crusty scabs on the skin surface that, if pulled off, will reveal a greeny-yellow pus with the protruding hair resembling paint brushes.
Mud fever can be extremely painful to touch, especially if secondary infection is present, but is rarely itchy. Frequently more than one limb is affected.
In severe cases, the whole limb may swell up and a secondary lymphangitis can develop. This is serious and requires intensive veterinary treatment usually including both intravenous antibiotics and anti-inflammatories.
Mud fever can occur on other parts of the body, especially the back, when it is usually called "rain scald".
Preventing
mud fever
• Ensure bedding is clean, dry and non-irritant at all times
• Avoid over-washing and/or too vigorous grooming
• When washing legs, use drying wraps/boots to dry legs quickly
• If bandaging, ensure limbs are clean and dry first
• Periodically disinfect all equipment, gear and stable surfaces, as they
could harbour dermatophilus spores
• Consider topical barrier creams (usually produced in an oily base) such
as tea tree oil, sulphur, MSM, Sudocrem, nappy cream, calendula and hypericum,
aloe vera, honey with vitamin E, liquid paraffin or baby oil, zinc + castor
oil cream, and petroleum jelly. Use on clean, dry legs or underside of belly
prior to turnout or exercise
• You may need to wash creams off legs with warm water and mild shampoo
once every 10 days or so
• Try using waterproof leg wraps for turnout
• If necessary, trim long hair off lower legs so you can monitor the area
and can apply protection more effectively. The old rule of "leave feathers
on" is not practical for horses turned out in wet and muddy fields
• Consider nutritional supplements for promoting a healthy skin, such as
soya/cod liver oils, seaweed (not for pregnant mares), antioxidants, herbs and
essential oils such as lavender, camomile and yarrow
• Rotate paddocks to avoid poaching
• Use electric fencing to block off muddy areas around gates
• Be vigilant. The sooner you spot the first telltale signs of mud fever,
the quicker you can take action and so prevent a lengthy, and costly, recovery
Treating
mud fever
• Make sure you know what you are treating. Correct treatment from the
outset can save wasted time and money.
• If the affected limbs are swollen or painful to touch then antibiotics
will be necessary.
• Remove the cause. If your horse is standing knee-deep in mud all day,
no matter how well it is treated, the mud fever will not go away. Keep your
horse in or turn out on to a manège or well-drained, dry field.
• If you have not already done so, clip away all hair from around the affected
areas. You will have to remove the feather in feathered breeds.
• Wash the area thoroughly using warm water. Once all the mud and dirt
has been removed, clean the affected area with very warm, dilute antiseptic
solution. Warm water opens the pores and lets the solution penetrate.
• Once thoroughly clean, leave the warm antiseptic in contact with the
skin for five minutes and then wash off - again with very warm water.
• Apply a wound gel. Do not use ointments initially. Your vet may prescribe
Fuciderm, an antibiotic gel, which works well in some cases.
• Dermapred (available on the internet) is a replacement for Dermobion
which was a very useful cream for healing mud fever
• Leave the area open to the air. Bandaging retains dampness on the skin
surface promoting further infection.
• Above all, try to keep your horse's legs dry.
• Make sure your horse is vaccinated against tetanus.
• If your horse is very sore painkillers or anti-inflammatories may be
needed.
• If scabs are very bad, applying nappy cream or sudocrem and completely
covering with clingfilm before bandaging overnight will help loosen the scabs