Understanding and Treating Common Skin Conditions in Horses

As misty dawn sets in over the farm, you head to the barn to check on your horse like always. You step into the familiar rhythm of the tasks: feeding him, brushing him, and—wait a minute. What are those unusual bumps on your horse’s skin? It’s easier said than done, but try not to panic. Horse skin conditions are somewhat common, and many of these skin disorders are treatable. The first step to taking any next steps is to learn the common signs and symptoms of a horse’s skin disease. Your horse could have one of several skin issues, but luckily, many at-home and vet-recommended skin health and treatment options can help your friend heal. Throughout this equine skin condition guide, you’ll discover nine common equine skin conditions and diseases in horses, skin problem symptoms to watch for, and treatment options.

Horse Skin Conditions

Like a person, a horse can develop an equine skin condition at any point throughout their life. Some skin disorders are hereditary, while some skin problems are caused by infections or allergies. Regardless of the cause of the skin issues, we know that noticing unusual symptoms on an affected area of your horse’s skin can be alarming. We’re here to help. Let’s take a look at some of the most common skin ailments your horse might be going through.

1. Ringworm

Ringworm is a fungal infection caused by dermatophytes, which eat keratin—or a protein that forms the structure of hair and skin cells. It causes round and hairless patches of scabbed or crusty skin. Often, you’ll notice these patches on the horse’s face, sides, chest, neck, or saddle area.¹ Some horses become itchy, while others experience little or no discomfort. Regardless, treating your pony for ringworm is crucial to help reduce and prevent the spread to other animals. Vet-recommended treatment options when looking at how to treat horse ringworm include²:

• Isolating your horse from other animals as quickly as possible
• Clipping hair around any lesions and removing loose scabs or crust
• Cleaning the ringworm patches with an antifungal antiseptic
• Applying an OTC antifungal medication

Repeat these steps as necessary, and expose the patches to sun and air to help kill fungi. If the condition doesn’t start to heal in about a week or continues to spread, contact your veterinarian.

2. Rain Rot

Rain rot (or rain scald) is another common skin condition in horses. Bacterial infections that can form in chronically moist environments are the leading cause of rain rot, hence its name. Bacteria that can grow on wet skin or hair can cause an infection when they reach a break in the skin, such as an insect bite or a cut. Symptoms of rain rot to look for include³:

• Scabby, crusty areas with raised bumps
• Tufts of matted hair (upright)
• Peeling crusty areas
• Bare spots with pus

You’ll often see these signs on areas of a horse that may be chronically damp, like their hindquarters, topline, shoulders, or lower legs. If you notice symptoms of rain rot in an affected area, it’s recommended to remove your horse from the damp environment and place it where the fur and hair can fully dry. Next, you can do a spot treatment or full bath with vet-recommended over-the-counter anti-microbial shampoos.⁴ Continue horse rain rot treatment for one week and call your vet if you don’t see improvements from their skin problems.

3. Dandruff

Dandruff is a common condition in humans—but did you know it’s often found on your horse, too? And that it can be dry or oily, just like ours? Primary seborrhea—or dandruff for short—is often a lifelong, hereditary condition. The secondary version has the same symptoms, but it occurs in a horse that has never had the condition before. Usually, it starts because of a secondary disease. Dandruff of either type can be⁵:

• Dry – Small flakes around the base of your horse’s mane and tail—or sand-like flecks on the girth and other sweaty areas
• Oily – Large, waxy crusts on areas like the elbows and lower legs that can peel and leave hairless spots

While treating dandruff is not required, many people do so for aesthetic reasons (show jumping, anyone?). Start by using a vet-recommended antidandruff shampoo to loosen scales and dissolve flakes.⁶ You can also scrub the hair with a soft-bristled brush to remove crusts. If desired, talk to your vet about other topical medications for dandruff.

4. Mange

Mange is a parasitic infection caused by mites. In the United States, it commonly affects the lower parts of the legs in horses with feathering, though it can also cause lesions on the⁷:

• Face
• Mane
• Tail
• Armpits
• Neck
• Jaw
• Groin
• Shoulders

When a horse has mange, it starts as small, round bumps that eventually grow into large bald spots with scaly or thickened skin. Your horse may itch, rub, stamp, and bite at the infected areas, sometimes until they rub their skin raw. Mange causes horses pain and discomfort, and sometimes permanent scarring, so prompt action is important. You can start by spraying, dipping, or sponging a topical antiparasitic product with a lime-sulfur solution on the affected areas.⁸ This is typically recommended three or four times about every two weeks. Vets may also recommend a course of ivermectin or moxidectin.⁹

5. Environmental or Contact Allergies

Similarly to humans, horses can have environmental and contact allergies. Many develop allergies to mold, dust, and pollen. These can cause hives on the face, neck, upper legs, and chest.¹⁰ Some horses have allergic reactions to ingredients they come in contact with, like shampoo or fly spray. These symptoms include flaky or itchy skin, redness, worsening hair loss, pain, or skin thickening. When treating a horse with allergies, keep your majestic friend away from their triggers whenever possible. Other vet-recommended solutions include¹¹:

• Trying different foods
• Vaccines
• Allergy supplements
• Sublingual immunotherapy

You may need to try one or a combination of these treatments to reduce your horse’s allergies. Consult your veterinarian about your horse’s unique case.

6. Eosinophilic Granuloma

Some horses’ skin reacts to insect bites, which often means they have eosinophilic granuloma. With that said, this condition also occurs due to environmental allergies and trauma. You’ll usually see a pony develop this disease during the warmest parts of the year, though it can be year-round. Symptoms of eosinophilic granuloma in horses include¹²:

• Lesions on the trunk, neck, and back that range in size
• Round or irregularly shaped masses that aren’t itchy
• Pea-sized nodules all over the body
• Calcified or hardened lesions

If you notice these signs, ask your vet about treating your horse for this condition. They may recommend oral or injectable corticosteroids and antibiotics for any secondary infections.¹³ Other solutions can include surgical removal of calcified lesions, fly control, and allergy remedies.

7. Saddle Sores

Saddle sores are a condition caused by the rubbing of a poor-fitting saddle or harness. It occurs in the area under the saddle, injuring the skin and soft and bony tissues. Signs your horse may have saddle sores include¹⁴:

• Inflamed skin sores
• Redness
• Cysts, bumps, and blisters
• Skin tissue death
• Inflamed and pussy hair follicles
• Warm, hairless, and painful spots
• Abscesses
• Localized loss of feeling
• Permanent scarring

If you believe your horse may have saddle sores, you should first replace any ill-fitting tack, including saddles and harnesses. Next, follow your vet’s recommendations for treatment, which may include skin wound treatment, rest, and using astringent packs and antibiotics.¹⁵ Sometimes, you may need to drain any hematomas or fluid pockets or have an equine vet surgically remove dead tissue.

8. Lice or Mites

Is your horse scratching at themself a lot? They could have lice—yes, the same thing that might instinctively cause you to scratch your head right now! Horses can have two types of lice¹⁶:

• Bloodsucking – Often found in the mane, tail, or hair above the hooves
• Biting – Burrowed into the skin on their sides, necks, and the base of their tails

Symptoms pointing to lice (or sometimes their insect counterparts, mites) include restlessness, scratching or biting fur, bald spots, or a dull coat.¹⁷ If your horse has mites or lice, it’s recommended to isolate them from other horses, animals, and people to help reduce contact and prevent spread. Disinfect and clean their environment thoroughly. Try vet-recommended sprays, shampoos, and powder to kill and remove the lice from a horse.¹⁷ You may need to repeat this treatment in a few weeks to prevent lingering eggs from hatching.

9. Photosensitization

Photosensitization occurs when a horse’s skin becomes overly sensitive to the sun’s ultraviolet rays. When exposed to the sun, photodynamic compounds on the skin activate, causing a chemical reaction that leads to cell damage, fluid buildup, and ulcers. Areas with less hair, like the ears, lips, and eyelids, are most susceptible to photosensitization.¹⁸ One of the horses’ most apparent signs of photosensitivity is physical discomfort when in the sun or scratching at those areas. When treating photosensitization, you’re aiming to soothe it. Keep your horses in the shade or inside the barn as much as you can, or let them outside at night. Some veterinarians recommend corticosteroids, though fly prevention and cleaning skin wounds are also beneficial.¹⁹

Support Your Horse’s Healthiest Skin

Now that you know more about your horse’s possible skin ailment, you can weigh your equine care treatment options and consult a veterinarian. At Vetericyn, we want to help keep your animals well, including your horses and ponies! Whether you need horse shampoo or ways to supplement your horse’s skin care treatment, Vetericyn is here to help. Shop our full selection of animal wellness products today online or at Tractor Supply, Amazon, or your local pet supply store. Or check out our other animal wellness blogs for more information on farm animal, dog, and cat care.

Reviewed by Solomon Benarroch, Veterinarian

Solomon Benarroch DVM has been a practicing veterinarian for over 30 years. His primary focus has been in equine soundness and performance sports medicine. Originally from Winnipeg, Canada he attended college at the Western College of Veterinarian Medicine. And completed an internship at the University of Minnesota. He is the father of three kids and when he isn’t working (which is rare), he enjoys traveling, cooking, and spending time with friends and family.

Sources:

1. Merck Manual. Ringworm (Dermatophytosis) in Horses. https://www.merckvetmanual.com/horse-owners/skin-disorders-of-horses/ringworm-dermatophytosis-in-horses
2. Equus Magazine. How To Identify 8 Common Equine Skin Diseases. https://equusmagazine.com/horse-care/common-equine-skin-diseases
3. Horse Illustrated. Scratch That: All About Common Horse Skin Conditions. https://www.horseillustrated.com/horse-skin-conditions
4. Merck Manual. Dermatophilosis ("Rain Rot") in Horses. https://www.merckvetmanual.com/horse-owners/skin-disorders-of-horses/dermatophilosis-rain-rot-in-horses
5. Equus Magazine. Get Tough On Dandruff. https://equusmagazine.com/horse-care/tough-dandruff-14524
6. Horse Side Vet Guide. Skin is Dry or Flaky, Anywhere on Body. https://horsesidevetguide.com/drv/Observation/427/skin-is-dry-or-flaky-anywhere-on-body/
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8. Merck Manual. Mange (Acariasis, Mange Mites) in Horses. https://www.merckvetmanual.com/horse-owners/skin-disorders-of-horses/mange-acariasis,-mange-mites-in-horses
9. HorseDVM™. Mange. https://horsedvm.com/disease/equine-mange
10. Merck Manual. Allergies in Horses. https://www.merckvetmanual.com/horse-owners/skin-disorders-of-horses/allergies-in-horses
11. DVM360. A closeup look at equine skin diseases. https://www.dvm360.com/view/closeup-look-equine-skin-diseases
12. Stable Management. Identifying and Treating Common Equine Skin Conditions. https://stablemanagement.com/articles/identifying-and-treating-common-equine-skin-conditions/
13. Merck Manual. Eosinophilic Granuloma Complex in Horses. https://www.merckvetmanual.com/horse-owners/skin-disorders-of-horses/eosinophilic-granuloma-complex-in-horses
14. Merck Manual. Saddle Sores in Horses. https://www.merckvetmanual.com/integumentary-system/saddle-sores/saddle-sores-in-horses
15. Merck Manual. Saddle Sores (Collar Galls) in Horses. https://www.merckvetmanual.com/horse-owners/skin-disorders-of-horses/saddle-sores-collar-galls-in-horses
16. Merck Manual. Lice of Horses. https://www.merckvetmanual.com/horse-owners/skin-disorders-of-horses/lice-of-horses
17. Blue Cross. Skin conditions in horses. https://www.bluecross.org.uk/advice/horse/health-and-injuries/skin-conditions-in-horses
18. Texas A&M Veterinary Medical Diagnostic Laboratory. Photosensitization: Causes and testing options. https://tvmdl.tamu.edu/2021/08/16/photosensitization-causes-and-testing-options/
19. Merck Manual. Photosensitization in Horses. https://www.merckvetmanual.com/horse-owners/skin-disorders-of-horses/photosensitization-in-horses