Understanding Equine Reactions: Allergies, Intolerances, and Irritations

Horses experience a variety of situations related to plants, insects and chemicals that can be the source of discomfort or a variety of clinical symptoms. These reactions can be broken down into three main areas: allergies, intolerances, and irritations. Let's talk about each today.

Feed or Food Allergies in Horses

A feed or a food allergy is an abnormal immune system reaction, generally to a specific protein in a specific ingredient in the feed or food supply.

Allergies may result in what we call urticaria (welts), plaque, bumps, or hives that we see on the skin. Sometimes called protein bumps, these are not a reaction to too much protein, but are a reaction to a very specific protein. This protein may come from a feed ingredient, but it may also come from ingestion or inhalation of other material or from something unrelated, like insect bites.

One horse in a herd may develop an allergic reaction while other horses are not affected. Identifying the specific allergen may require exclusion feeding or highly specific allergy testing. In humans, the extreme example is something like a peanut allergy where a very small quantity can create a life threatening situation.

Feed or Food Intolerances in Horses

A feed or food intolerance is not the same as an allergy, although there may be some similar symptoms. Digestive disturbances occur when an individual is not able to properly digest a specific ingredient. Human examples may include such things as lactose intolerance or gluten intolerance. This has not been well identified in horses, but may be possible.

Irritations Caused by Contact with Specific Substances

An irritation occurs when the horse comes in contact with specific substances that cause tissue irritation. For example, a horse that is sensitive to the chemicals in a particular grooming product or fly spray may break out or experience skin irritation and loss of hair. Insect bites may cause both an allergic response and a surface irritation. Chemical irritants from plant, insect, or synthetic sources may cause skin surface reactions as well.

If you're noticing unusual skin symptoms or digestive disturbances in your horse, just remember: Such things may require careful observation (and sometimes a bit of luck) to determine the underlying cause. It can be very useful to work with your veterinarian to determine the exact condition and search for potential causes. And should you need to try changing up your feeding regimen to find something more suitable for your animal, give us a call or stop by. Our associates are standing by to help!

NOTE: This post is adapted (with permission) from content proudly brought to you by our partners at Nutrena and Cargill Animal Nutrition. The original article appears here.