Winter ailments: Mud, glorious mud

December 3, 2018

Mud, wet and cold brings a whole new range of problems to prevent, manage and treat. Here are a few of the common problems and methods to go about treating them.

When the weather turns and winter rolls in, it may be tempting to layer on the rugs and bring your horse into the stable if it is an option, but in reality many horses do well living out in the winter, as long as they have adequate shelter and care. Skin conditions such as rain scald and mud fever are some of the biggest problems, and rugging up may not make any difference at all as they are both bacterial issues and can set in if any skin becomes sore or broken, such as through too much moisture which breaks down the skin’s surface. Both can occur on any horse, although heavily feathered horses and those with pink skin are more susceptible. The trick is to ensure that if legs get wet – through rain or washing – they are dried as well as possible, and you remain vigilant checking for broken skin.

Mud fever

Mud fever can range from a minor skin irritation to full-blown, lameness-inducing infection. Cracked heels or pastern dermatitis occurs when there is constant wetting of the heels. This could be during exercise, when walking through moist grass when turned out or living in damp bedding. The condition arises because the heels never properly dry and instead a moist dermatitis develops in the skin folds of the heels which can progress to cellulitis. Mud fever is often the term given when the pastern dermatitis is linked to oedema, heat and pain. It’s not just those that live out that are at risk, so good stable management as always remains key in winter.

Once mud fever has set in, treatment can actually be quite difficult, not least because it can be very difficult to keep the area dry. There is no standard treatment for mud fever and what works for one horse may not work for another. Each vet practice makes up its own mud fever creams. Regardless, the necrotic debris should be debrided before topical treatment is applied.

If there is serious scabbing and crusting, dermisol cream can be used for debridement. It can be covered in loose layers of cling film and covered in a bandage and left for 12 hours. It is important that any scabs removed are disposed of and not left around as contamination. The area can then be washed gently with hibi scrub and re-examined. If there is still debris the dermisol treatment can be repeated. If the area now shows pink skin with deep cracks antibiotic ointment should be applied and barrier cream before exercise. After exercise the legs must be hosed off and it is very important that the area is completely dried with a clean towel before antibiotic ointment is reapplied.

If the limb is swollen or the horse is lame pain relief may be indicated. If the clinical signs are severe and there is cellulitis systemic antibiotics may be required.

Rain scald

Dermatophylosis or rain scald occurs secondary to profound wetting of the skin and the presence of the specific microorganism. The distribution of rain scald lesions are the same as the pattern of water run off.

The condition is most common in horses living out side in wet summer or winters and mild forms can be seen following a single heavy downpour, often on the face and hindquarters. The condition can be seen when wet horses are rugged. Clipping and shampooing normal horses removes the oil coat from the fur and makes them more susceptible to rain scald.

The affected skin is hard and has a cardboard feel to it. The fur is matted and may have serum oozing from around the hair base. If the hair is pulled it may come out in a paint brush clump as the scabs clump several hairs together. In severe cases the animal may seem unwell.

Treatment for rain scald varies depending on the severity of the condition. Systemic antibiotics may be required in severe cases. Topical treatment can be used such as pevidine iodine scrub then rinsed and dried with a towel. Prevention in susceptible horses is crucial. They should be removed from the rain, not rugged when wet and shampooing and clipping should be avoided. Dry rugs and numnahs should be used at all times and not shared between affected horses. Grooming kits should also not be shared between horses.

An all round approach to winter health

Vigilance would be the best way to avoid winter problems. Horses should be regularly checked. This will ensure outdoor horses will have a constant water and food supply despite the worsening weather conditions. Pasture management is also key: poaching can create issues so ensure the pasture is regularly checked. Winter can be a time for weight loss in older horses so it useful to regularly weigh tape so action can be taken before the problem becomes too severe. Conversely winter can be a good time for targeted weight loss for overweight animals as less forage is available. Arthritis can often appear worse in cold conditions so pain management may need to be considered if horses appear particularly stiff during colder conditions. Boredom is another thing to watch out for if a horse is increasingly stabled during winter.