Feeding and Managing Horses with Allergies

What are allergies?

An allergy is an inappropriate immune response to a specific protein, or allergen, in your horse's environment.

What causes allergies?

Allergies can develop in response to allergens that are eaten, inhaled or touched by your horse, or even injected during insect bites or stings. The most common allergy in horses and ponies is to midges. Some horses may have allergies to red and white clover, but true allergies to other feeds are very rare. Allergies have been reported to barley and haylage. Contact allergies are rare in horses, perhaps because their skin is protected by their coat, but are most commonly linked to plants, bedding, insect repellents or creams.

How do allergies develop?

To develop allergies horses become 'sensitised' to a particular allergen - this involves development of the antibody IgE. When your horse is exposed to the same antigen in the future IgE causes a chain reaction within the immune system. This involves histamine release from mast cells which contributes to itchiness and hives.

What are the symptoms of food allergies?

Signs of food allergies often involve the skin, gastrointestinal tract or both. Horses may be itchy or develop urticaria (hives). Hives can be any shape or size, appear on any part of the body, and feel warm to the touch. You may also see scabs, areas of hair loss or self-trauma. Gastro-intestinal symptoms may include diarrhoea or colic

What are the symptoms of contact allergies?

Symptoms are similar to those of food allergies but can progress to swelling, hair loss, and the formation of thick, painful scabs.

Identify the allergen:
Lessening the symptoms is very difficult without reducing exposure to the antigen causing the reaction. Your vet will take a detailed history to try and identify what may have caused the allergic reaction. They may also take a biopsy of your horse's skin or conduct intradermal skin testing. If your vet suspects a food allergy they may place your horse on a dietary exclusion diet. This involves temporarily removing any foods which may be associated with allergies for 8 to 12 weeks. The vet will then reintroduce elements of the original diet and if your horse starts showing symptoms again this will indicate which protein may be causing the problem. Frequent rubbing of the tail and hind-end could be due to pinworms, rather than allergies.

Reduce Exposure to the Antigen:
If the food containing the antigen has been identified your horse can be fed a diet avoiding this food. Some horses may be allergic to certain types of grass. In these cases, it may be better to feed haylage or seed hay instead of meadow hay. If your horse could be suffering from a contact allergy it may be beneficial to bathe the area with a mild oatmeal or children's shampoo and avoid washing powders or fly sprays that may cause your horse to react

Avoiding exposure to inhaled antigens such as pollens or mould spores can be more challenging. You should ensure that stables are clean and dust free and stabling during the day when pollen count is highest could help. Hygiene analysis of your forage is recommended to ensure that it does not contain high levels of mould spores. Soaking your hay for about an hour will reduce the levels of dust and spores.

Additional Support:

• Omega-3 fatty acids have been shown to counteract the inflammatory process during an allergic reaction. Feeding around 75ml of Flax or Linseed Oil, which are high in these fatty acids, could be beneficial
• Ensure that your horse receives enough vitamin E and selenium as these antioxidants can help to reduce inflammation
• If you are feeding less than the recommended amount of your horse's feed make sure to top up with a vitamin and mineral supplement
• Imbalances in bacterial growth in the hindgut have been implicated in the development of feed allergies. Feeding a probiotic or prebiotics to provide digestive support may be beneficial
• Natural herbs such as chamomile, garlic and nettle could support the management of itchy skin

We are here to help!
Unfortunately, there is no guaranteed cure for allergies but providing the correct diet and careful management can help to relieve your horse's symptoms. Our team of Nutritional Advisors are on-hand to offer free, friendly and practical feeding advice that can really make a difference to your horse or pony's life.