A more appropriate term for a food allergy is an adverse reaction to food. It occurs when the ingestion of a certain ingredient in the diet causes itchiness anywhere on the body, skin infections, hair loss or ear infections with Malassezia yeasts and bacteria.

Common areas in the body of the dog that are

Food allergies can also cause symptoms inside the digestive tract, such as stool mucus, blood in stools and increased frequency of defecation. These symptoms have been associated with an increase in flatulence.

The cause of the adverse reactions to food is unknown, but research points to an increased permeability of the gut wall, or a failure of the gut-associated immune system. Although it has never been shown that certain breeds are affected more than others, some breeds appear to be over-exposed to this condition. The age of onset can vary from a few months up until they are12 years old.

What are the ingredients that produce the more adverse reactions in dogs?

There are 7 ingredients that are often responsible for adverse reactions to foods:

1. Beef

2. Milk

3. Eggs

4. Chicken

5. Soy

6. Wheat

7. Corn

Statistically, meat and soy are the biggest offenders. Many dogs are allergic to more than one of these ingredients, and may also be allergic to other things in their environment, such as pollen or fleas.

How can a food allergy be diagnosed?

If a dog has been itching all over and the symptom does not subdue in the winter months, recurring skin and ear infections, or intermittently loose bowel movements, you should investigate whether the dog could be suffering from a food allergy.

There are three recognized diagnostic methods:

1. Blood tests to measure antibodies to various ingredients.

2. An intradermal skin test where allergens are injected in different parts of the skin and the reaction is measured.

3. An elimination diet.

The elimination diet is seen as the most reliable, and cheapest of the three options. However it requires a motivated and disciplined owner in order to achieve significant results.

The elimination diet

There are three basic options in the elimination diet:

1. Homemade food

This is not recommended because it is necessary that the owner invests a lot of time and also is capable of providing a natural, nutritionally balanced diet. However, if the dog is very restless and the owner cannot implement this regime to its full extent, commercial feed is available, the best ingredients are lamb, fish, duck or turkey as protein, rice or potatoes as a carbohydrate. Owners should look for products that the dog has not eaten before.

2. A commercial diet, limited antigen

Suitable ingredients for this diet are deer and rabbit as protein, and oatmeal or chestnuts as carbohydrate. Remember, we are looking for ingredients that your dog has never eaten before.

3. Hypoallergenic diet. -Hydrolyzed proteins -

They contain proteins that are broken down to the extent that they are no longer capable of causing an allergic reaction. They are usually for prescribed diets because they generally are purchased through a vet, although they can be obtained without a prescription. These foods are much more expensive than the limited antigen diets.

The elimination diet should be done for a minimum of six weeks, and possibly extended up to 10 weeks, in order to observe the long term effects. Owners should not give their dogs reward candies, supplements or treats during the trial period. For example, many owners give dry leather from cow or pig hides, these being the most common cause of allergies. During the trial period, the dog should only eat the diet selected and water.

If symptoms are intense itching, many veterinarians prescribe antihistamines or steroids during the first weeks of testing in order to make sure the dog is more comfortable. If the dog shows improvement, stop using the antihistamines, continue their diet to see if symptoms return and thus confirm the diagnosis. Usually this process takes 3 to 7 days, if the symptoms return you will have to take other measures to isolate the problematic ingredient.

If there is a partial improvement in the state of the dog, it is likely that the dog actually has one food allergy and perhaps an environmental allergy at the same time. In this case the dog should be kept on the elimination diet, while other possible allergies are investigated, such as the itching of flea bites or atopic skin. These can be proven using the intradermal test or blood test.

If a food allergy is confirmed, the owner may continue feeding him the same food as used during the elimination period indefinitely, or can persevere with introducing dietary trials of the 7 most common allergic ingredients (see above), one by one until it can be determined precisely what the dog is allergic to.