Everything Explained - Food allergy and Intolerance

The popular press often feature articles on food allergies and intolerances suggesting that they are responsible for a variety of problems including bloating, lethargy and blotchy skin. It is also an increasingly frequent topic of conversation on the Dengie Feedline with owners reporting symptoms including itchiness, over-excitable or irritable behaviour and loose droppings. But what is actually meant by the terms allergy and intolerance and how serious a problem are they?

What is a food allergy?

A food allergy is defined as an immune-mediated adverse reaction to food. In practice this means that the body has a reaction to a food which would normally not cause a problem for most individuals. Food allergies are triggered by allergens such as specific proteins found in some foods. An allergic reaction can range from a mild condition such as urticaria (lumps and bumps on the skin that may or may not be itchy) to very serious conditions such as anaphylactic shock caused, for example, by peanut allergy in humans.

What is food intolerance?

In contrast to an allergy, food intolerance is a non-immune mediated adverse reaction to food. This type of reaction does not involve the immune system and tends to illicit milder symptoms than a food allergy. An example would be lactose intolerance in humans. 

How frequent is food allergy and intolerance in horses and ponies?

Food allergy and intolerance is a poorly researched area of equine nutrition with most texts stating that true food allergy in horses is rare. Horses with a food allergy are likely to exhibit symptoms such as urticaria all over their body and not just within one location such as under the saddle where contact allergies may occur.

When it comes to food intolerance the definitions of this in horses is much hazier. The reason for this is that many people would describe a change in their horse’s behaviour, such as becoming more excitable, as an intolerance to a type of food when in fact there are many other issues that could be involved. For example, excitability in horses may be related to the amount of energy consumed in relation to workload, variability in exercise level and even environmental factors such as how windy it is.

What if my horse has a food allergy or intolerance?

If you suspect that your horse has an allergy or intolerance it can be very tricky to get to the bottom of the problem, especially as there are so many other things in the horses environment that may trigger an allergy or that can affect their behaviour.

To help to try and determine the cause of allergy or intolerance an elimination diet can be tried and should be carried out in conjunction with your vet. This usually involves taking the horse off of the current feeding regime to see if the problem is resolved. To confirm the cause it may be necessary to reintroduce feeds one at a time although many people choose not to do this and just avoid the ingredients that were most likely to have caused the problem.

Fact or fiction?

When it comes to food allergy and intolerance there are a lot of common feeding myths to be dispelled!

My horse is allergic to protein – fiction!

This is a very common misunderstanding often due to the fact that some allergic conditions in horses such as urticaria are also called protein bumps. An allergy is not caused by the amount of protein found within the diet, but instead by a specific allergen, which is a specific type of protein, found in some foods. For example, if a person was allergic to the protein in peanuts they could still eat meat which also contains protein.

My horse is allergic to sugar – fiction!

Molasses is often said to be the cause of allergies and because it has a high sugar content horse owners assume that all sugar is going to have the same effect. People frequently call the Dengie Feedline asking for a sugar free diet plan for their horse when what they probably require is a molasses free ration.

My horse is allergic to cereal grains – possibly

It is possible for some individuals to be allergic to cereal grains as some are known allergenic foods and this may result in symptoms such as urticaria and itchy skin. Rice is often referred to as hypoallergenic and so may be a suitable alternative to other cereals.