Allergies are the result of an exaggerated physical reaction by the immune system to normal substances in the horse's atmosphere. During warm summer weather, horses are often exposed to more allergy-inducing plants, insects, substances and situations than during colder weather.

Woman inspecting horse

If a horse has a healthy immune system, fighting off allergens will be easy, but, if the immune system is compromised in any way, allergies can become a serious problem.

When confronted by allergens, the horse's body produces antibodies that cause biochemical changes in the body including excessive antihistamine release, thereby producing symptoms and signs of the allergy.

Excessive inflammation has been linked to a number of horse health issues and has a clearly defined role in allergies, watery eyes and nostrils, hives, sensitivity to bug bites, some intestinal problems, a variety of skin inflammations and an increasing number of auto-immune health challenges.

Allergies are related to many normal substances in the environment including sensitivity to inhalants produced by pollens, grasses, weeds, shrubs, molds, oats, wheat, barley, corn, and barn dust, as well as ingredients in commercial horse foods. Certain foods, feeds, grains, hay varieties, and nutritional supplements may trigger allergies.

Other causes include reaction to chemicals in tack supplies, insect saliva, and products used in the stable area. Skin allergies are often caused by insect bites resulting in hives or welts as a result of the build-up of proteins called antibodies.

Horse allergies can take years to develop. Undetected allergies are difficult to prevent and diagnose initially. If a horse has a healthy immune system, fighting off allergens will be easy, but, if the immune system is compromised in any way, allergies can become a serious problem.

Preventing allergies in your horse

Keeping the environment clean and insect free, and changing the bedding often is key to prevention. In some cases, using shredded paper or rubber mats for bedding will help prevent or resolve allergy problems.

If horse allergies are caused by foods the horse is eating, a veterinarian or an equine nutritionist can help determine which foods are causing the allergies. Elimination of those foods that are causing allergy symptoms, and following a recommended diet for horses with allergy problems is helpful when food allergies are involved.