Horse owners frequently battle skin conditions. Here, we present horse care knowledge to help identify, treat and prevent skin conditions on horses!

Your horse’s skin is up to four times more sensitive that a human’s. Not only is it more sensitive to touch, but with thick coats and outdoor lives, their skin is very susceptible to skin conditions. An investigative approach to equine skin care is your best defense. There are multiple causes of skin conditions on horses ranging from allergies, to bacteria and fungus, to behavioral issues and insect bites. Excess moisture in their environment is often a big factor. Consistent grooming, managing turn-out and pasture time during rainy seasons, proper nutrition and veterinary care will all help reduce instances of equine skin conditions, but they cannot be prevented 100% of the time. When skin conditions on horses do show up, you need to be able to recognize them and address the cause, while also treating the condition so that it does not progress.

When do I know my horse has a skin condition?

• Skin conditions on horses often present with scabby lesions, bumps (hives) or reddened areas
• Hair may be falling out in an area
• Sometimes there are areas of raised hair with lesions, flaky skin or scabs underneath
• You see your horse obsessively rubbing or scratching a specific area
• *Note that lighter skinned horses (pink skin instead of dark skin) can be more vulnerable to skin conditions

Common Equine Skin Conditions

Rain Rot

(Also Known As: Rain Scald, dermatophilosis or streptothricosis)

Rain rot is a bacterial infection brought on by moisture. Horses naturally carry the bacteria with them and when their skin stays wet for extended periods of time, the bacteria take hold. It is especially common in warmer climates, though can still occur in cooler rainy conditions.

Signs of rain rot:

• Lesions or scabs
• The hair is sometimes raised in the area
• It usually happens on the horse’s back (top line) and flank, though it can occur other places like their face

See Figure 1

Preventing rain rot:

• Make sure the horse has a chance to dry off regularly during the rainy season under a lean-to or inside the barn
• Frequent grooming – use a stiff curry to loosen dander and dirt from deep within the coat, then use a stiff brush to brush it away

Treating rain rot:

• Bathe with an antibacterial shampoo
• While bathing, it is recommended that you gently remove scabs once they are softened, but be gentle; it can be very sensitive
• Follow up with a topical antibacterial treatment
• Cases of rain rot can heal on their own, but it is recommended that you treat them to keep it from worsening and to prevent further damage to the skin and coat

Scratches

(Also known as pastern dermatitis, greasy heel, dew poisoning, mud fever)

This is an infection associated with the lower limb, and one of the more common skin conditions on horses. Chapped, raw skin from prolonged moisture encourages microbial infections of bacteria or fungi or sometimes mites. The condition can be exacerbated by “feathers” of hair around the hoof which keep the pastern from drying out. Left untreated, it can lead to increased swelling further up the leg, infection and lameness.

Signs of scratches:

• Swollen reddened skin around the pastern skin and lower limb
• Small scabby bumps often in a line resembling a scratch
• It is more common on the rear legs, but occurs on the front legs too
• Light colored (pink) skin is a little more susceptible than dark skin

See Figure 2

Preventing scratches:

• Clip the long hair around their lower legs before the wet season begins.
• Keep the footing dry in the stalls and turnout area.
• If you notice dew often forms on their grass, try turning your horse out a little later after the dew has dried.

Treating scratches:

Persistence is required, it can take several months to clear up completely.

• Start by clipping or scissoring away any long hair around the affected area
• Gently wash with a shampoo made for treating fungal and bacterial skin conditions.
• Dry the area with towels, or if your horse will allow it, use a hair dryer – getting the area completely dry is vital to the healing process
• Apply a topical treatment made for fungal and bacterial skin conditions on an ongoing basis according to the instructions
• If the affected area doesn’t start to respond to treatment, or if the horse has a severe case of scratches with leg swelling or lameness, contact your veterinarian immediately

Ringworm

(Also known as: fungal dermatitis)

Ringworm is a fungal infection of the skin. It is usually seen on the side of the neck, though it also occurs on other areas like the face, barrel or the flank. Important! Ringworm is contagious to people and other animals. After treating the horse, sanitize your hands, tools and work surfaces.

Signs of ringworm:

• Ringworm can present as circular areas of flakey skin
• The hair in the area will be scruffy or raised slightly
• Unlike some other skin conditions on horses, there will be no heat coming from the skin, no redness, scabs, itchiness or pain when touched

See Figure 3

Preventing ringworm:

• Sanitize the stall floors, blankets, tack and grooming tools with bleach or other sanitizer
• There are multiple species of the fungus that causes ringworm which live on various surfaces, so a fungal culture done by your veterinarian will often help guide your sanitation process

Treating ringworm:

• Clip away the hair in the area – fungus likes darkness and moisture
• Scrub the area with an antifungal shampoo and rinse with clean water
• Dry as well as you can
• Apply an antifungal treatment on an ongoing basis according to the directions
• Evaluate progress after two weeks – the lesions should be shrinking and new hair will be growing from the affected areas
• If it is not clearing up, it could signal a more serious infection – call your vet

Allergic Reactions

Reddened skin and / or hives are a common result of an allergic reaction. Just like people, many different substances can cause an allergic reaction in a particular horse. It could be something that touches their skin, something they breathe, something they eat or even a new medicine or vaccination from the vet. Allergic reactions can be one of the more frustrating skin conditions on horses because it can be complicated and difficult to diagnose.

Many horses are severely allergic to the saliva from bites of insects – especially small gnats, sometimes called no-see-ums. The resulting welts and irritated skin is often referred to as “sweet itch.” The horse will scratch themselves constantly resulting in lesions. Sweet itch often shows up in fly season along the top-line of the horse or the tail dock area.

Signs of a skin allergy:

• Raised welts or hives in a large area of the horse’s skin
• Reddened skin
• Will not have the same characteristics of other skin conditions like flaking skin, or scabs

See Figure 4

Preventing / Treating a skin allergy:

If your horse is having a severe attack, or symptoms are worsening, your veterinarian may decide to administer a cortisone shot or other treatment to lessen the effect of the allergen. In the long term, treating an allergic reaction presenting in a skin condition is best done by figuring out what is causing it, then removing that factor completely from your horse’s life. Work closely with your veterinarian and provide them with as much information as you can. An allergic reaction often happens within a few days of the horse being exposed to the allergen. Try to think of anything new that your horse has touched, breathed, eaten or been treated with. It can be as subtle as a change in brands of a horse care product, tack or bedding. Or it may be something that is brand new to your horse care regimen.

To further complicate diagnosis, there is sometimes an underlying factor in your horse’s system. A high-quality, fresh-ground flaxseed supplement rich in healthy Omega 3 fatty acids can provide immune support.

If you suspect the reaction is insect related, check with other horse owners nearby – they may be having the same problem and that knowledge may lead you in the right direction. Sweet itch can be treated and prevented by using a quality fly spray, using fly sheets and adjusting your turn-out schedule to avoid the insects. If you do these things and the symptoms start to go away, you’ve likely found the cause.