Is Your Pet Allergic to His Dinner?

It comes out of nowhere. One day your cat or dog is frisky and frolicking without a care. The next, he is itching, scratching, or licking himself excessively and you cannot get him to stop.

Signs like these can signal many different illnesses, but a skilled veterinarian can quickly narrow down the possibilities. While it is not likely, one potential cause could be the food you have been feeding your pet for months or even years.

According to Dr. Dunbar Gram, an owner of Animal Allergy and Dermatology located in several Virginia cities, a sudden violent reaction with no obvious cause could be the result of a food allergy.

An allergy is a breakdown of the immune system that causes the body to react to harmless substances. Food allergies are a reaction to a specific type of food, or foods, that your pet eats. Both cats and dogs experience similar signs, and there is no strong link between specific breeds and food allergies.

SIGNS OF TROUBLE
“Dogs suffering from a food allergy mostly itch and chew themselves,” says Dr. Kinga Gortel, a staff veterinarian with the Animal Dermatology Specialty Clinic in Marina del Rey, California. “Cats tend to lick themselves as a way to relieve itching. They groom excessively.” Dr. Gram agrees: “When I have a cat come in with the sudden onset of an itchy face, I immediately suspect food allergy.”

In some cases, the signs are a bit more messy. “Some dogs and cats with food allergy show signs of gastrointestinal upset, diarrhea, vomiting, or increased bowel movements,” explains Dr. Gortel. This digestive distress can occur alone or in conjunction with the itching. Recent research has even linked food allergy to recurrent ear infections.

Unlike allergies caused by inhaled pollen, mold, or dust, which can often be diagnosed at an early age, it takes extended exposure to incite an allergic reaction to food, and one can appear at any time. That is why dogs and cats that have been eating the same food for months or years with no problem can suddenly develop a food allergy. “It is the one type of allergy we see at any age,” says Dr. Gortel. “It can occur in very young pets or very old pets that have been eating the same food for a long time.”

While the reaction to a food allergy is typically quite severe, food allergies are not as common as you might believe. According to Dr. Gortel, food allergy is the least common type of pet allergy, estimated to account for only 5% to 10% of all allergic reactions in dogs and cats, ranking below flea bite and inhalant allergies. The difference is that flea and inhalant allergies can be ruled out with simple tests while it takes a lot longer to diagnose a food allergy. “Blood and skin tests for food allergies are not particularly accurate,” says Dr. Gram.

SIMPLE MEALS, SIMPLE DIAGNOSIS
If your veterinarian suspects that your dog or cat has a food allergy, she will likely recommend a hypoallergenic elimination diet. This type of diet limits your pet’s meals to a single protein source, such as rabbit, duck, or venison, and a single carbohydrate source, such as potato. “The diet is chosen based on the pet’s dietary history,” explains Dr. Gram. “We try to find substances the pet has not been exposed to in the past.”

Elimination diets are complete and balanced with all the essential proteins, fats, vitamins, and minerals necessary for your pet’s needs. Your pet should be switched to the diet over several days, adding more to what is currently being eaten until the switch is complete.

During the trial period, owners must be strict in feeding their pet only water and the ingredients of the diet. “That means no additional treats, flavored medications, or table food,” says Dr. Gortel.

The reason is simple. The diet is intended to remove food that causes your pet discomfort. “Most treats contain a mix of ingredients that might have caused your pet’s allergies,” says Dr. Gram. “We can be flexible later on, but during the testing you need to be strict.”

Dr. Gortel explains, “If you are feeding a rabbit-based diet and your pet occasionally gets a treat with chicken in it, it is still enough that the hypoallergenic food will not be as effective.” He adds, “The only treats you can feed are items that have the same ingredients as the elimination diet.”

Both Drs. Gortel and Gram recommend that the pet stay on the elimination diet for at least 8 to 10 weeks—longer if your pet continues to show signs of the allergy. Once the signs disappear, your veterinarian may suggest something you think is crazy—putting your pet back on his old diet.

“Once we find a diet on which the pet does well, I try to reexpose him to his previous diet to prove that it was indeed the cause,” Dr. Gortel says. This is called rechallenging. If the signs reappear when the old food is reintroduced, your veterinarian can definitively say that was the cause of the allergy. In most cases, signs of an allergy will return within a day or two of ingestion, although it may take up to 10 days or so.

LIVING ALLERGY FREE
After you know for certain that your pet suffers from food allergies, and you know what foods cause the allergies to flare up, you can slowly relax the rules. “Keep your pet on the hypoallergenic diet, and introduce new foods one by one to see if he can tolerate them,” offers Dr. Gortel. “If there is a reaction, signs should appear within days of eating the allergenic food.”

When testing is complete, you can even consider going back to your preferred brand. “Pets do not have to stay on the elimination diet used during testing,” Dr. Gram says. “In the end, they may go to a chicken-based diet instead of beef, or beef instead of lamb.” Just make sure none of your pet’s forbidden foods is on the ingredient list. Even a little is too much.

In the end, the simplest solution is to find something healthy and safe that your pet likes and stick to it. Cats and dogs are content eating the same food every day. As Dr. Gram says, “For many pets, once you find a diet that works for them, it will work for them forever.”

STEROIDS: TEMPORARY RELIEF ONLY
If your pet experiences an extreme allergic reaction, your veterinarian may recommend a steroid shot to provide relief. While your pet’s discomfort will end almost immediately, steroids are not a cure for what ails him.

“You do not want to use steroids on a long-term basis because they hide the problem, not treat it,” explains Dr. Dunbar Gram. “When the steroids go away, the itching and scratching will return.”

At most, a steroid shot should be given only to provide relief from food allergies until an elimination diet can be implemented. “Steroids have a whole host of side effects and are beneficial in only about 50% of food allergy patients,” Dr. Gram says. “They are not healthy for your pet long term.”