Skin Bumps and Hives on Horses

Horses can develop bumps and hives, just as human do. Even if your horse does not show signs of discomfort from the hives or bumps, you can be sure that he is indeed uncomfortable, so have him checked by a veterinarian as soon as you notice any skin abnormalities. That way, you can rule out more-serious conditions and provide relief to your horse as quickly as possible.

  1. Allergies

    • Just like humans, horses experience allergic reactions -- to insect bites, certain foods, some topical ointments and substances in the environment, such as pollen and molds. Hives are a typical reaction to an allergy. A veterinarian can determine whether the reaction is due to a food allergy. If it is, you may have to make some changes in your horse's diet. Also, horses are just as susceptible to insect bites as humans are, so spray your horse with a pest repellent to keep mosquitoes and other biting insects at bay. You can make one yourself that's free of harsh chemicals, since some horses may develop an allergic reaction to irritating substances -- such as commercial insect repellents -- used on their skin.

    Sarcoids

    • A sarcoid is a growth that typically develops around the ear. It starts as a flat, wart-like growth and becomes larger, firmer and more rounded. Although it's generally harmless, a sarcoid can be bothersome if it develops near the eye or if it grows too quickly, so it's best to have it treated as soon as possible. Cryotherapy and laser surgery are two treatments used for sarcoids.

    Melanomas

    • Mostly found in gray horses, melanomas are cancerous growths that most frequently appear on a horse's anal, genital or throat latch area, although they can also grow on the inside of a horse's mouth. Surgery is a viable treatment option, although surgery cannot remove all melanomas. Also, melanomas tend to recur in horses.

    Collagen Granulomas

    • Collagen granulomas are raised, tender skin bumps usually found in the area where the saddle tree or girth sits on the horse. It's easy to spot these bumps, since hair tends to grow very thinly over them. In order to relieve the pain for your horse, a veterinarian can inject the bumps with cortisone. If collagen granulomas develop frequently, consider using a pressure-relieving saddle pad when riding.

    Environmental Reactions

    • Sometimes horses develop rashes or hives due to environmental reasons. When they're exposed to sun and high temperatures for extended periods of time, for example, they may develop hives -- a similar condition to heat rash. Also, pesticides and other chemicals can irritate a horse's sensitive skin -- sometimes causing massive irritation and bumps all over its body.

    Infections and Diseases

    • Horses are susceptible to a number of infections and diseases. A common equine fungal infection is ringworm. Caused by Trichophyton equinum, the infection causes lesions to form and hair to fall out. These lesions can be found anywhere on the horse's body, although they typically develop near the eyes and on the neck. Other infections and conditions that cause skin lumps and hives include dermatophilosis, acne and warts, to name a few.