Feed Allergies and Intolerances

Does your horse or a horse you know react badly to a change of feed? Does his behaviour become sharp, fizzy or excitable? Does his coat become dull and scurfy? Perhaps you notice lumps and bumps appearing under the skin? Maybe you even notice loose droppings or mild colic symptoms? If you’re reading this and these symptoms sound all too familiar but you just can’t figure out the root cause, then it may be time to re-evaluate your horse’s diet.

We commonly find that Barley, Molasses and Alfalfa are ingredients that can cause unwanted reactions in some horses, making our Barley & Molasses Free Range of feeds an ideal choice.

For some horses, allergies and intolerances can take weeks, months or years to develop, meaning that their once favourite food could begin to cause unwanted and adverse reactions. Each horse will react differently and feed intolerances can affect your horse’s behaviour and health in numerous ways, such as;

  • Hives
  • Itchy or scurfy skin
  • Loss of hair
  • Sharp, fizzy or excitable behaviour
  • Regional swellings
  • Digestive upsets
  • Loose or watery droppings
  • Decreased performance

Food allergies are quite rare in horses whereas intolerances to a specific feed ingredient are far more common and it seems the number of reactions in horses is increasing just as it is in humans.


Food Allergy: The immune system is provoked after consuming a specific feed ingredient causing a rapidly progressive, life threatening reaction such as Anaphylactic Shock.

Diagnosing a true food allergy can be done by means of a simple blood test carried out by your vet. When a horse is reacting to an allergen, the immune system will release an increased number of antibodies called Immunoglobin E (IgE) which will show during the blood test to confirm the cause of reaction. However, it is important to bear in mind that blood tests used in veterinary medicine are still not 100% reliable and can still throw false positives.


Food Intolerance: The horse consumes a feed ingredient causing an unpleasant reaction yet does not provoke a full allergic reaction.

Finding out exactly which feed ingredient the horse is intolerant to can be a tricky task, as if the antibodies involved do not spark a true allergic reaction, then this may not appear visible when the blood test is taken and analysed, so, we are no closer to a true answer.

However; there is a way we can get a good idea of the feed ingredient causing these unwanted reactions; by process of elimination.
Many horses will live their lives with low level sensitivities to certain feed ingredients and we, as owners, soldier on with everyday life thinking the problem will pass. For many of us, this will carry on until their health is compromised in some form such as; stress, depression, irritation or generally being run down.

Unfortunately, using calming supplements and soothing creams will not fix the problem, this will only disguise it. Not cure it.
Ask yourself this; if you knew eating cheese gave you spots, would you lather your face in cream or would you just simply stop eating cheese? We know what our answer would be!

This is why it is important we find the root cause, as by continuing to feed the offending feed ingredient(s), this can worsen the horse’s health and in some cases can even increase the number of feed ingredients your horse reacts to.
If you become concerned about your horse’s health and the unwanted reactions are worsening, the first step should be to get in contact with your vet for guidance. Your vet may recommend implementing an elimination diet at first instance to get to the bottom of the problem.

Using an elimination diet is the only way to find a definitive answer as to what’s causing these unwanted reactions. This process will normally take place over two to four weeks and will involve removing the suspected offending ingredient from the diet, if the horse improves; this will indicate that this is the ingredient that the horse is intolerant to. At this point, the suspected offending ingredient should then be added back into the diet to see if things become worse again – if so, this will then confirm that the suspected ingredient is in fact the root cause of the unwanted reactions. This process can become tricky when multiple feed ingredients seem to be causing the reactions, therefore, it would be important to only re-introduce one suspected ingredient back into the diet at a time.

When changing a horse’s diet, we would recommend changing the diet over a period of 7-10 days; gradually feeding less of the original feed whilst introducing small quantities of the new feed. The amounts fed of the new feed should then be slowly increased depending on your horse’s condition and energy levels. Slowly changing the horse’s diet is also a concept that should be applied if you are thinking about adding or changing a supplement or chaff in the diet – by doing this, you can make sure your horse is able to tolerate that particular item.

If you think your horse is suffering from an intolerance and you’re not quite sure where to start and want some friendly, helpful advice; contact our award winning nutrition team on 01362 822902.