Researchers Itching to Find New Equine Skin Allergy Tests

Cornell University veterinarians are trying to find better ways to test for skin hypersensitivities (allergies), which affect approximately 3-5% of the equine population, so they can ultimately improve relief for these itchy animals.

Skin allergies are economically important, aesthetically displeasing, and distressing to the horse, owner, and treating veterinarian. Largely due to the lack of efficient or efficacious tests for skin allergies, horses aren't typically diagnosed until they've developed advanced pruritis (itchiness) and alopecia (hair loss), often in combination with secondary bacterial infections of the skin.

According to a recent study performed by Bettina Wagner, DVM, PhD, and colleagues from the Department of Population Medicine and Diagnostic Sciences at Cornell University's College of Veterinary Medicine, two types of tests are currently available to test horses for allergies: intradermal (in the skin) testing and serological (blood) tests. Using these techniques, 10 horses were tested for 61 common equine allergens, including Culicoides (a genus of biting midge), grasses, and pollens.

"While the blood test evaluated in this study provided only limited diagnostic information, intradermal skin testing can also be difficult to interpret because allergic horses often show numerous positive reactions," reported Wagner. In addition, intradermal testing can be costly, labor-intensive, and it requires shipping the horse to a testing facility.

Wagner further explained, "Without good diagnostic tests for skin hypersensitivities, appropriate and effective treatment options cannot be developed. Current treatments used commonly include orally administered antihistamines and corticosteroids.

"Steroids are capable of controlling the clinical signs of allergies, but they are associated with a wide array of serious adverse effects," said Wagner. "My recommended treatment for skin allergies is allergen avoidance." This includes changes in housing to minimize exposure to allergens, use of blankets, and not turning horses out during times when midges are flying.

Owners of allergic horses who want to contribute to research on this disease can submit blood samples from their horse to Wagner (

The study, "A comparison of intradermal testing and detection of allergen-specific immunoglobulin E in serum by enzyme-linked immunosorbent assay in horses affected with skin hypersensitivity," is scheduled to be published in an upcoming edition of Veterinary Immunology and Immunopathology. Contributing authors were Morgan (DVM student), and Miller, DVM, PhD.

About the Author

Stacey Oke, DVM, MSc

Stacey Oke, MSc, DVM, is a practicing veterinarian and freelance medical writer and editor. She is interested in both large and small animals, as well as complementary and alternative medicine. Since 2005, she's worked as a research consultant for nutritional supplement companies, assisted physicians and veterinarians in publishing research articles and textbooks, and written for a number of educational magazines and websites.

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