Mallenders in Feathered Horses: Causes, Treatment, and Management

Mallenders may not be a condition every equestrian is familiar with. However, feathered horses, like cobs and draft horses, are uniquely prone to Mallenders.

This genetic disease of the skin is not curable, however, there are things horse owners can do to treat and manage the symptoms and Mallenders flare ups.

What is Mallenders?

Mallenders appears as scab or scale that is thickened or crusted, and is overall rough-looking skin, typically found behind the horse’s knee. Thought to be areas of a keratinization defect, the layers of skin affected by Mallenders are not formed properly.

Hair loss, or matted hair with a thick discharge, can also be present along with swelling and elevated temperature.

Typically, horses will have a pain response to being touched near the area where Mallenders is present. Pressure or flexion of the affected limb can also be painful.

While Mallenders is commonly found on the back of the horse’s knee, it’s important to note it can affect other areas of the body as well, such as in horses with chronic progressive lymphedema (CPL) or chronic proliferative paster dermatitis (CPPD). Chronic progressive lymphedema is a condition that has a significant impact on the draft horse population. This condition causes symptoms like swelling, scaling, and dermal fibrosis along with secondary infections.

What Causes Mallenders in Horses?

The overproduction of keratin, also known as hyperkeratosis, is the root cause of Mallenders. Keratin is a key fibrous protein that is naturally found in a horse’s hair and hooves, but causes problems when it is overproduced.

Horses that have feathering have more hair, and this makes them more genetically prone to this overproduction of keratin versus other non-feathered breeds.

Mallenders can be triggered by things like feather mites or other superficial injury to the skin. Wet, muddy, and other conditions conducive to bacteria growth are also triggering for Mallenders.

Mallenders Treatment Options

Mallenders can be very painful for horses if left untreated, and the scabs can crack and weep, exposing the body to secondary conditions.

These secondary conditions include fungal and bacterial infections, such as staph infections, which often occur if Mallenders is left untreated. These secondary conditions cause additional irritation and can even potentially lead to lameness. Antibiotics may be necessary, especially if a secondary infection occurs.

Feather mites are something else horse owners should be mindful of because mites feed on the dead skin of the scales, can trigger or worsen Mallenders flare ups, and are common.

The best thing horse owners can do topically for horses with Mallenders is to keep the area clean and dry and avoid damp and warm conditions where bacteria thrive. However, it’s important to be aware that drying the skin out too much causes it to crack and bleed. Avoid perfumed soaps and chemical-based products which can contribute to over-dry skin.

After bathing, applying a vet-approved wound cream might be a good option to prevent over-drying.

Keep the feathered areas especially clean and well-brushed as this will also help with airflow, which can aid in healing.

How To Manage Mallenders Long-Term

While there is no cure for Mallenders, there are things owners can do long-term to help decrease symptoms during flare ups. Being diligent in monitoring the areas where flare ups occur is always important.

Supplements that help support a healthy coat and skin, such as those with Omega 3’s, could also help horses with Mallenders since they are a natural anti-inflammatory. Wholesome Blends® Omega Plus, features a blend of hemp, canola, and flax oils that support hair coat, skin, body condition, and immune system health.

Since vitamin C is an important nutrient that supports the formation of collagen and internal wound healing, being sure your horse isn’t vitamin C deficient could help horses with Mallenders. This can help keep wounds from re-opening, which decreases the risk of secondary infection. Vitamin C is also an antioxidant, meaning it inhibits free radical formation, which can be damaging to a horse’s skin as well as muscle and nerve tissue. Using a ration balancer, like Essential K®, can help ensure horses are getting the vitamins, including vitamin C, and other antioxidants they need.

Catching and preventing infection early is key. Because feather mites are known to cause problems for horses with Mallenders, diligent treatment and prevention of mites is important. Talk to your veterinarian about other mite treatments and prevention, as well as the possibility of oral treatments or keeping the horse’s legs clipped, for this reason.

Using topical shampoos and treatments as needed, such as those with anti-fungal and antibacterial properties, is also important. Just be sure to thoroughly dry the horse’s legs after bathing.

Keeping the horse’s environment as clean as possible and frequently washing and disinfecting things like grooming equipment, could aid in helping prevent and treat Mallenders flare ups overall.  

Article By: Sarah Welk Baynum
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