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Allergy Testing in Dogs

Learn about allergy testing techniques for dogs.

Dogs can suffer from different types of allergies. Most of the time, dogs with allergies exhibit skin problems such as scratching and licking incessantly, losing hair, and developing secondary skin infections that can cause redness, swelling, and pustules on the skin. Learn more: "Dealing with Canine Itching and Scratching."

The most common allergies in dogs are flea, food, contact, and inhalant. Sometimes, the signs the dog shows can be subtly different depending on the allergy's cause, but often, that's not enough to definitively diagnose the trigger.

Other clues, such as the seasonality of the condition, can help a veterinarian make a diagnosis. For instance, if the dog is only itchy in the fall, inhalants that come out at the time of year are likely to be the cause.

In situations in which clues like that don't help, some testing may be required.

Food Allergy Testing in Dogs

If your veterinarian suspects that your dog may have an allergy to a component of their diet, a food trial is the preferred method of testing for that.

There are some blood tests available for food allergy, but they are generally regarded to be inaccurate and are certainly not as useful as a food trial.

During a food trial, the dog is fed a hypoallergenic diet and does not receive anything else to eat, including treats, for a period of six to eight weeks while the owner observes the signs of allergy to see if they improve.

Learn more: "Food Trials in Dogs."

Blood Tests for Allergies in Dogs

There are some blood tests available for allergy testing in dogs. Their reliability is variable, but the test is fairly non-invasive, requiring only a simple blood draw, and it may give an owner enough information to make significant environmental changes to help decrease the dog's symptoms. Allergy injections may also be formulated based on serum test results.

Skin Tests for Allergies in Dogs

Skin testing is considered the gold standard for diagnosing inhalant skin allergies (atopy) in dogs. This test is usually performed by a veterinary dermatology specialist. An area of the body is shaved and a tiny bit of each of the allergens the vet wishes to test for gets injected just under the skin. Then, the owner and vet monitor the skin for a reaction, which is usually redness or a small bump that looks like a mosquito bite, that indicates the dog is allergic to that allergen. Generally, many allergies are tested for at once.

If your dog is on medications for their allergy symptoms, those will need to be discontinued for a period of time before the allergy testing, so they don't interfere with the test.

What Happens After Allergy Testing?

After the skin or blood testing reveals probable allergens, the lab will create a serum containing those allergens. The owner will learn to give injections and follow a prescribed course, with the allergens gradually increasing to trigger the dog's immune system so it can learn to deal with them normally rather than overreacting.

The veterinarian will teach the owner how to watch for adverse reactions and give detailed instructions for the owner to follow.

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Food Allergies in Dogs

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