Feed allergies are rare in horses while intolerance of a specific feed is much more commonplace.
If a horse has a feed intolerance, the culprit is usually barley or wheat, but other cereals can be implicated. Feedsthat contain cereal by-products can cause a reaction.
To establish which feed is responsible the horse will need to be placed on an exclusion or elimination diet. Working horses will need light or no work until the offending feedstuff is found.
A horse that has a feed intolerance may remain susceptible for many months or even its entire lifetime, although allergic bumps may disappear suddenly with the removal of the problem feed.
A practical feeding solution for horses with a cereal intolerance is a grass- or lucern-based diet with non-cereal products on top.
Add milk pellets to the diet of a horse that requires extra condition. Vitamin and mineral supplements based on limestone will add the necessary micronutrients to the diet.
Beware of feeding allergy-free compound feeds, because they are likely to contain some cereals or cereal by-products.
Beware the bugs
Forage mites in hay or straw are a common source of allergy and irritation. Lumps or “hives” around the face and neck suggest hay, while those on the legs and belly implicate straw.
Feeding hay on the floor or replacing straw with another type of bedding will alleviate both these problems.
Allergies do not cause raised temperatures or a fever. Lumps and a high temperature can suggest equine herpes. Other symptoms include oedema of the legs and sheath as well as a runny nose and eyes.
See Horse & Hound issue dated 23 November for further information.