Is Your Dog Allergic To His Food?

Your dog itches. He scratches. He still itches. Nothing you do for your dog helps. He scratches until his skin becomes raw and infected. What’s the cause?

A dog scratching himself silly may seem like a minor issue to all but the tormented dog. But itching is the number one skin problem seen by veterinarians. Common causes of itching are fleas, mosquitoes, bacterial infections, mange, mites, ticks, lice, and reactions to medication.

Eliminate those possibilities and what’s left? It could be that your dog is allergic to his food, or more accurately, to something in the food.

According to “Small Animal Allergy: A Practical Guide,” approximately 15% of American dogs suffer from allergic diseases. The most common allergic disease is flea allergy dermatitis (FAD). FAD is an allergic response to the flea saliva transmitted in a flea bite.

Another common cause of skin problems is allergy to pollen, grasses or other substances in the air or on the ground. Symptoms may include face rubbing, chewing under the legs, and foot licking.

Most of these causes of itchiness are seasonal. Fleas, ticks, mosquitoes and pollen allergies all occur at specific times of the year.

If your dog is itchy all year round, or if he has skin problems all the time, the cause could be a food allergy. Food hyper-sensitivity is the third most common type of canine allergic disease.

A food allergy can develop after the dog has been eating a food for some time. The dog becomes more sensitive to the food ingredient the more he is exposed to it. Food hypersensitivity  can strike at any age.

Don’t confuse food allergies with food poisoning or digestive disorders. The clues to these problems are gastrointestinal symptoms. The dog will throw up, or have diarrhea. Allergies, on the other hand, are usually skin related.

How To Test For A Food Allergy

After you and your veterinarian rule out the other causes of itching (fleas, pollen, grasses, mites, and skin diseases) you and your vet can try testing different dietary combinations.

You’ll need to run at test for at least a month to reach any conclusions about a particular diet.

You may have heard that one diet or another is “hypoallergenic.” Many people, including those who should know better, think it means that a food will not cause allergies. That is not true. Hypoallergenic means it is less likely to cause an allergic response.

It is because of the confusion surrounding the term “hypoallergenic” that pet food industry regulators (AAFCO and FDA) swung into action. They forced pet food makers to eliminate the word from their labels and literature, unless the health claim could be proven and documented in scientific tests, thus proving the food is non-allergenic.

Thus, no one diet is hypoallergenic. However switching to a food which your dog hasn’t previously encountered could eliminate the substance causing the allergic response.

Commercially-made lamb and rice-based dog foods are a relatively recent innovation. If your dog has been on a food whose main ingredients are beef or chicken, the lamb and rice diet can be a good starting point for testing for a food allergy.

There are other choices for determining if your dog is allergic to his food. You could try a turkey-based food, a rabbit-meat food, or a venison dog food. All are sold in pet stores.

While proteins are most often the culprits in food allergies, your dog could be allergic to ingredients such as soy, wheat, corn or egg – any of which may be found in common brands of dog food.

If your dog is on an Economy brand of dog food, try moving up to a Super-Premium food from your pet store. Super-Premiums are made with better-quality ingredients, and usually don’t have artificial colorings or other ingredients which might be causing the problem.

For a true food allergy test, select a very different food, such as a lamb and rice diet. Introduce the food over a three day period, mixing 1/3 the first day with 2/3 of the old diet, 1/2 and 1/2 the second day, and 2/3 of the new diet on the third day.

As in any good scientific study, you’ll want to control any outside variables which could influence your test. Feed in a ceramic or stainless steel bowl – not plastic. Plastic bowls are porous, and may retain food residue even after washing.

Don’t give any snacks, commercial or otherwise. Don’t give rawhide or other toys to chew on. Limit vinyl toys, as well. Talk to your vet about possibly restricting your dog’s medication for the duration of the test.

Then keep a daily record of your dog’s comfort level. Is he scratching as much? In the same places? Is he pawing his face, rolling on his back, and chewing? Has the skin color changed?

If a food allergy is the problem, you’ll see a significant improvement in a few weeks. According to a recent study (Rosser, 1993), 25% of dogs put on this kind of elimination diet had relief in three weeks (the standard time recommended). About half the dogs tested showed improvement in 4 to 6 weeks, and the rest took up to 10 weeks on the test diet .

To verify that food hypersensitivity was the problem, consult with your vet about putting your dog back on the old diet for two weeks to see if the allergy returns. Make no other changes – keep him away from snacks and toys. If the itching comes back – usually within a week – you’ll know for sure it was the food to which your dog was allergic.

If your dog was free of symptoms on the new diet, add back treats and toys one at a time. Watch to see if these are the culprits.

If your dog still has problems on the new diet, you and your vet will have to go through a new process of elimination to determine which foods your dog can eat safely. Feed one food at a time for several weeks and see what happens. If itching disappears, you’re on the right track. If not, try a different food.

If your dog can’t tolerate any commercial food and you have found the foods he can eat, start cooking dinner for your dog. Ask your vet how to make a complete and balanced diet, and which vitamin/mineral supplement will supply your dog with his requirements. (You will need to give a supplement to your dog if you are cooking for him.)

Allergic dogs may be allergic to many things. Food may only be one piece of the puzzle. Your dog may be allergic to flea saliva, and also be allergic to pollen or mold. The dog may be able to live with those allergies without major itching. But add in a food sensitivity, and it becomes too much for the dog’s body to handle.

In dogs who have multiple allergies, reducing the contribution of any one may lead to success. Eliminate the fleas and the food allergy may no longer be important.

Don’t let your pet suffer. Seek out the cause of his itchiness, and eliminate it. He’ll be your best friend forever.