Your dog is itching like crazy and shaking his head constantly. Your vet just told you it could be a food allergy. What does that mean? To find out, we talked to Susan Wynn, an internationally known expert on holistic pet care. Wynn is former president of the American Holistic Veterinary Medical Association, a clinical resident in nutrition at the University of Tennessee College of Veterinary Medicine and author of four textbooks on integrative practice, focusing on dietary supplements such as nutraceuticals and herbs.

Q: How common are food allergies in dogs?

A: Ten percent of all allergy cases in dogs are food allergies. Dogs also can suffer from food intolerance, which is different from a food allergy.

Q: What are the signs of a food allergy?

A: Anything from chronic ear inflammation, gastrointestinal problems, and chronic diarrhea to chronic gas, licking their feet, or an itchy rear end. More uncommon, and probably not agreed upon, symptoms might include seizures, asthma, and chronic sinusitis/rhinitis.

Q: What are the most common things that could trigger a food allergy in my dog?

A: It’s a genetic problem, and when it’s triggered, it’s by exposure to whatever they’re allergic to. The most common allergens are beef, dairy, wheat, egg, chicken, lamb, soy, pork, rabbit, and fish. And, most dogs are usually allergic to more than one thing.

Q: What causes these allergies?

A: It’s a multi-factorial thing, but certainly you have to have a genetic predisposition to develop allergies. The environment can affect it, too.

There’s a lot of research going on right now to determine what, in early puppyhood or early kittenhood, makes the immune system more likely to express that trait. There’s an immune education process happening in the first few weeks of life. Young animals treated with antibiotics could potentially be predisposed to problems later in life because antibiotics change the environment inside the gut, which is the largest immune organ in the body. That could be a predisposing cause, but then the trigger would be being exposed to the allergen.

Q: Are some breeds more prone to food allergies?

A: There are some, but I think it depends on whom you talk to. It also can vary by country or part of the country. It may be as simple as what breeders, with their line-bred family of animals, are in your area. So if you have a very prominent breeder who is breeding a line known for their allergies, you’re going to think that breed commonly has food allergies. In my experience, retrievers, German shepherds. Dachshunds, cocker spaniels, and rex cats are the most commonly affected breeds.

Q: How do I determine if my dog has food allergies, or something else is causing the problem?

With or Without Foods Allergies, Dogs Should Never Eat These Foods