What is a food intolerance?

A food intolerance is an adverse reaction to a food, one of it's ingredients or additives. It differs from a food allergy in that

the immune system is not involved. Food allergies typically cause non seasonal itching, especially around the head & face, swollen & inflamed areas on the face & ears, hair loss due to itching, vomiting & diarrhea.

A common food intolerance that many people have heard of is milk. This is because many mammals lack the enzyme necessary in order to digest the lactose in, which is the major sugar in milk.

The most common causes of food allergies & intolerances in cats are fish, beef, eggs, wheat &  milk.  Cats can become allergic & intolerant to foods they have eaten for a long period of time.

What are the symptoms of food intolerances?

As you can see above, vomiting & diarrhea are symptoms which can also be displayed in a cat who is allergic to a food, however the allergic cat also has other symptoms such as itching, which is caused by the immune response.

• Vomiting
• Diarrhea
• Abdominal pain
  

How are food intolerances diagnosed?

Food intolerances cannot be tested for like food allergies, so they can be harder to diagnose.

Your veterinarian will place your cat on a food trial which usually lasts between 8-12 weeks. During this time, you must not give your cat any other foods, vitamins, minerals or chewable medications apart from the prescribed diet. If any other foods or vitamins are given during this trial it will invalidate the results. If the allergy clears up after the specified time then a food allergy is the likely cause. The diet given to your cat during the trial will be a food the cat has never had before such as rabbit, duck or venison. The diet may be home made or a special 'prescription' diet.  This is known as 'elimination food trial'. After the trial, if the cat's allergies have cleared up it will be placed back onto it's regular food & if after a short period of time the allergies return then it is safe to conclude that the food was the cause of the allergy.

After the trial you may be asked to 'challenge' your cat by  re-introducing one ingredient back into the diet. If after 2 weeks the re-introduced food hasn't caused a flair up then add another ingredient & so on. If the allergy returns with the re-introduction of the ingredient then this is eliminated from the diet once again.

How are food intolerances treated?

Avoiding the food which caused the intolerances is the best method of treatment. This may either be a home made diet or a commercial one. If you are feeding a home made diet it is important to ensure that your cat is receiving the correct nutrients in the diet.