WebMD reveals the signs, symptoms, and triggers for food allergies in dogs.
Sandy Eckstein WebMD Pet Health Feature
Amy Flowers, DVM
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.
tumors are not common. They tend to occur in middle-aged and older dogs. The highest incidence is found in the short-nosed
breeds that have large-domed heads, including the Boxer, Bulldog, and Boston
Terrier. Tumors that can metastasize to the brain include cancers of the
mammary glands, prostate, and lungs, as well as hemangiosarcoma.
Symptoms depend on the tumor’s location and rate of growth. Tumors in the
cerebrum produce seizures and/or behavioral changes. The dog may exhibit
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 common 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.
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
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?
A: There’s only one way to diagnose food allergies accurately, and that is
an elimination diet and challenge. So what we do is take the dog off all the
foods it's eating and we put him on a food that he's never had before. With all
the exotic diets out there now, this can be pretty difficult. I've sent people
out for alligator and yak. Once the dog has improved, we start reintroducing
the old foods that we think caused the problems in the first place. If he has a
reaction, which usually takes a few days to a few weeks, then we know he has a