Allergies are fairly common both amongst humans and dogs, and just like a human, a dog can develop an allergy at any age. The most common dog allergy is against flea bites, and the second most common is inhaling allergens such as pollen or molds. Dog food allergies come in a close third place.

In order to develop dog food allergies, a dog must be exposed to the same food ingredient for a couple of years or more. Most dogs are between two and six years old when food allergies are first noticed.

What causes food allergy?

An allergy is caused by the immune system responding to something it believes is foreign. It is a defense mechanism that would normally protect the body, but instead causes an over-reaction to harmless substances met in everyday life.

When it comes to dogs and food the immune system most often reacts to a protein, and the most common triggers are beef, milk and other dairy products, chicken, eggs, soy, corn, and wheat.

What are the symptoms of food allergies?

Symptoms of food allergy include excessive scratching and itchy skin. A dog with a food allergy can scratch until they lose all hair in an area, and the skin is often red and irritated. This is particularly common on the ears, groin, and belly. Some dogs with food allergies lick or chew on their paws, get repeated ear infections, and/or rashes. Stomach problems are also often connected to food allergies.

How do you treat a food allergy?

To treat a food allergy, the dog needs to stay away from eating the problematic ingredient. Unfortunately, it can be difficult to find the problematic ingredient. The idea is to eliminate potential causes of the problem through feeding the dog something completely different from what he or she has eaten in the past. The new food – and nothing but the new food – has to be fed for two to three months to give enough time for the method to work. This means no treats or tastes of human foods, which can be frustrating for both dog and human.

Once the dog is symptom free, one ingredient can be added back at a time to see if the immune system reacts.