What is it?
The term mud fever is a colloquialism that refers to a large number of skin conditions found in horses, all of which look to be caused by dermatophilus congolensis, an infectious element that is prevalent in wet and muddy areas. Naturally, this means that wet weather and inclement seasons makes it shockingly common. You may have heard mud fever referred to by the medical name of pastern dermatitis, but riders often call it “cracked heels” or “greasy heels” as well.
It can be difficult to spot straight away as mud fever is an infection that can lay dormant for a long time, only becoming active when the skin is broken or softened. Excessive exposure to moisture and wet conditions will speed up the activation process. Infection spores, when active, spread from the infection origin site in every which way, leading to a serious inflammation and pain.
Why are horses prone to mud fever?
Put simply, horses’ skin is a perfect breeding ground for a huge number of bacteria, not to mention parasites and a host of other seemingly nasties, but they cause no harm and live symbiotically rather beautifully. As long as the skin is healthy. As soon as damaged skin comes into play, however, the eco-system, as it were, is disrupted and the organisms have a clear and easy path into the horse’s body. Add in damp conditions and suddenly, you have a real problem.
What causes mud fever?
There are so many potential issues that can lead to a healthy horse developing mud fever but the most common include:
- Certain soil conditions can make it possible for numerous animals to become infected at the same time
- Regular washing of limbs without requisite drying afterwards
- Standing in mud or soiled bedding for long periods.
- Excessively damp conditions
- Sweating beyond the normal expectation, while wearing rugs and tack
- Skin damage
- Unhealthy skin in a general sense, couple with a poor immune system
- Photosensitive skin
- Limb feathering is often considered to be a cause, but there is no real evidence for this
What are the signs to look out for?
Once lesions are visible, the signs of mud fever are easy to spot. Be aware that they are most commonly located in areas that are regularly subjected to getting wet and those that are prone to injury.
Symptoms can include:
- Multiple scabs, in amongst knotted hair
- Discoloured discharge oozing from beneath scabs
- Deep lesions at the back of legs, particularly, horizontal ones that split open
- Moist ulcer-like fissures under scabs
- Hair loss, revealing red, sore-looking skin
- Heat and swelling
- Tiredness, melancholy and loss of appetite in serious cases
How is mud fever treated?
Keeping infected site clean and dry will be your first port of call, so if at all possible, be sure to keep your horse stabled and out of inclement weather. After this, treatment can seem very daunting and a little upsetting.
Specific mud fever treatment will usually need to be applied underneath scabs, to guarantee maximum penetration, so scabs will need to be removed. This is often a traumatic and painful experience, so your horse might need to be sedated, for their comfort. Particularly ingrained scabs could need soaking prior to removal as well. With scabs removed, infection sites should be washed with a mild disinfectant, surgical scrub or a medicated shampoo, with careful rinsing carried out afterwards.
When clean, limbs will need to be properly dried. Blot excessive moisture away first and then use a hairdryer to eradicate every drop of moisture. When fully dry, a cream or lotion can be applied, but take advice on which ones to use. Anti-inflammatory creams can be brought into play, but only if the skin is fully clean and dry.
Bandaging is recommended, but only when the skin has been properly treated and the bandage expertly applied. A poor bandaging technique can encourage a persistent bout of mud fever to reoccur.
Be aware that recovery can be dependent on more than one cycle of treatment and will likely take a number of weeks. Prescription medication should only be administered by your vet and will be given on an individual basis. While treatment is normally effective, in some cases, you might find that limb weakening is an issue and that scarring can occur. Blood samples might be taken by your vet, just to be sure that the infection hasn’t spread.
How can you prevent mud fever?
When you know what causes mud fever, you can take active steps to minimise the risk for your horse, but widely recommended actions include:
- Only lay clean, dry bedding
- If an infection takes hold, stable, if possible
- Disinfect your yard, stables and equipment semi-regularly
- Avoid washing too much or grooming too thoroughly
- Look into potential barrier creams but only use on clean and dry limbs before going outside
- Don’t overuse creams, as they can cause a build up
- Waterproof leg wraps are a good idea for turnout
- Natural healthy skin supplements are a good form of prevention, but be careful if you are treating a pregnant mare
- Block off muddy areas to prevent access
- Be aware of sand ingress causing skin damage. Sand schools can be extremely prevalent to mud fever
- Keep your eyes peeled and always be on the lookout for the first signs of infection