Horse Allergies


Allergies, Hives, Urticaria, Dermatitis, Hypersensitivity,


Many things can cause allergic reactions. Some people feel that just like humans, pollution in the air, food and water are making horses more sensitive to their environment. Common allergens include:

  • Feeds and Fodders including weeds horses should not, but do eat
  • Insects
  • Pollen from weeds, gardens and trees
  • Grooming Sprays
  • Shampoo
  • Fly Sprays
  • Synthetics or Finishes on Equipment
  • Dust and Moulds
  • Medications or Supplements
  • Chemicals such as crop sprays
  • Bedding Materials

In short, anything that your horse can ingest, inhale or come into contact with could potentially cause an allergy. Of course, most horses can cope with most allergens, but some horses, like some people, develop sensitivities for no obvious reason.




Many allergic reactions start out with hives. The hair coat stares slightly and you can feel the raised bump on the horse's skin. Hives can be tiny or large. Eventually, the hair may fall off of the hives leaving behind tender patches. There may also be flakes of dander and itching or sensitivity.

Many times hives disappear as mysteriously as they've appeared. Other allergic reactions take longer to clear up. Horses may rub their tails on fence posts or scrub their manes out scratching their necks on feeders, branches or trees.


If pollen or another inhaled irritant is causing the problem, your horse may also cough, have a slightly runny nose and eyes (some clear discharge is perfectly normal) or have slightly raspy breathing. Severe allergic reactions might include edema. Contact dermatitis will appear as a sensitive area where a piece of equipment has been on the horse, or something like a grooming or bug spray has soaked through the hair.




Allergic reactions tend to come and go quickly and in some cases your horse may be over the symptoms before you've figured out what caused them. You may find the horse reacts at the same time each year, or perhaps never again. If the allergies don't clear up quickly and are causing you or your horse a lot of distress, veterinary testing may help determine what is triggering the allergy. Or, in the case of our Arabian mare, the cause may be very apparent. Corticosteroids or antihistamines may be used to quell the reaction. Some owners feel they've had success with supplements that boost immunity like omega 3 fatty acids, blue-green algae, and TCM.

Itching and irritation can be treated with soothing topical washes, ointments or lotions.



The only sure way of preventing an allergic reaction is to separate the horse from the allergen. It may take extensive testing to find out what exactly is causing the allergic reaction. Once the cause is determined, you will have to either remove the cause, or move the horse to another location. Sometimes neither is possible. In the case of our August 'breakout' horses, there are too many to find other places to live and too many plants to figure out what the cause is. Thankfully, it is always a mild reaction, unsightly and slightly itchy, that disappears within about ten days. For horses with severe allergies, your veterinarian should be able to provide you with medications to combat the symptoms.

If the horse is very distressed however, relocation may be the only solution.


Buckwheat, marshmallow, garlic and aniseed may be used to combat seasonal (hayfever) allergies. Vitamin C in the form of sodium ascorbate may also be helpful.

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