Equine Allergies

Horses can have allergies.

An allergy is a condition in which the body reacts adversely to a certain substance. The reaction might appear locally in the skin or can involve other body systems.

Food Allergies

Check the hay before feeding.

"A better term for the condition would be adverse reactions to food," according to Dawn Logas, DVM, Dipl. ACVD. Food allergies are rare and typically occur in horses that are 1 to 10 years old, are non-seasonal, and not usually affected by environmental changes.

Skin Allergies

Another form of allergy is atopic dermatitis--sensitivities from contact to the skin. Fly spray, shampoo, some plants, molds, danders and bedding can cause atopic dermatitis.

Insect Allergies

Blanketing your horse can protect it from insects.

Almost any type of fly bite can cause adverse reactions--eosinophilic granuloma--but most bothersome are gnats, according to Stephen White, DVM, Dipl. ACVO. The reaction first appears as a benign raised, firm nodule. It is much firmer, raised and more permanent than hives and will not flatten out when you press on it.

Symptoms

Symptoms vary, but can include serious nasal discharge, sneezing, itchy skin, antipodean-vascular reaction that causes swelling in the capillaries, papules, excoriations, erythematic, loss of hair, lesions, gastrointestinal problems and pyroderma.

Treatment

Remove nettles from pasture areas.

If you suspect your horse is having a reaction caused from contact with an allergen, try giving him a bath with a mild shampoo. In more severe cases, treating the horse with corticosteroids can shut down the allergic reaction. For a horse with chronic hives, regular low doses of a corticosteroid are the best course of action, according to Mansmann.

References

• Merck Vet Manual: Localized Anaphylactic Reactions
• The Horse: Skin Problems in Horses

Resources

• The Horse: Diagnosis and Management of Equine Food Sensitivity