What is food allergy?

Food allergy is one of the five most common allergies or hypersensitivities known to affect dogs. Most people know someone who is allergic to certain foods, such as strawberries or nuts. It is only recently that food allergies have become recognized in dogs. The signs are usually itchy skin (especially ears and feet) or an upset stomach. Other more subtle changes can also occur including hyperactivity, a poor haircoat, weight loss, lack of energy and even aggression. Like people, dogs may take years to develop allergies to their food, just because they have been on one type of food their entire life does not mean they cannot develop an allergy to it later on in life.

Food allergy is different. Antibodies are produced against some part of the food, usually a protein. In a pet with food allergy, the immune system overreacts and produces antibodies to substances that it should normally tolerate. This excessive response is termed an allergic reaction. Most pets with food allergies have itching rather than vomiting or diarrhea and can often get ear infections.

The most common food allergies in dogs are proteins from dairy products, chicken, beef, or gluten (from wheat). Each time a pet eats food containing these substances, the antibodies react and symptoms such as itching, vomiting or diarrhea occur. It only takes one mouthful to cause a recurrence of the symptoms.

No, virtually any food or ingredient can produce an allergy. Proteins are the most common cause but other substances and additives can also be responsible. Ex. Treats, food dyes in colored treats or food, pigs ears, beef chews, table scraps, etc.

How is the condition diagnosed?

Feeding an elimination diet is the best way to determine the presence of a food allergy. This is a hypoallergenic diet which contains none of the ingredients of the previous diet. Elimination diet trials have to be fed for a minimum of 8 to 12 weeks and no other food or treats should be fed until the trial is finished. Once your dog is no longer itchy you can reintroduce treats one at a time, once a week. If your dog becomes itchy again you will know which treats are causing problems. It will take another 4-6 weeks without those treats before your dog stops being itchy.

Occasionally commercial diets containing the right constituents may not be available or your pet will not eat them. If this occurs, you may have to prepare a home cooked diet.

Can the problem be cured?

No. The only "cure" is avoidance. Some pets will require medication during severe episodes but most pets can be successfully treated with a hypoallergenic diet.

Is it likely that my dog could develop other food allergies?

It is not uncommon for dogs that have developed an allergy to one particular food to develop other food-related allergies. Additionally, most dogs with food allergies are also allergic to fleas, pollens etc.