Testing Your Dog for Allergies
The goal of allergy testing is to develop a specific therapy for the dog’s allergy trigger. First, however, you have to identify your dog’s allergy trigger(s) which is done in one of three ways: food trial, blood tests or skin pricking test.

vet with dog

Food trial

This is the least expensive test but the one that takes the longest to see results. Your vet will give you instructions on the process.

Your dog will be on food with limited ingredients and unusual sources of protein and carbohydrates such as rabbit and rice for up to 12 weeks.

During the test period, your poor dog can’t have any other food or treats. He can’t even have a flavored toy or chew or toothpaste. This is truly an exclusion diet.

Your vet will monitor your dog and if the food trial appears to improve your dog’s
well-being, the vet will then re-introduce ingredients from his former diet to see what triggers his allergy.

My Toy Poodle went through this and it was a difficult period for both of us. She’s doing great now that we eliminated chicken from her diet.

Blood Tests

Blood tests detect and measure the amount of allergen-specific antibodies in a dog’s blood. When your dog comes into contact with an allergy trigger called an allergen, his body makes antibodies against it.

Allergy blood tests usually screen for at least 10 of the most common allergy triggers, including dust, fleas, pet dander, trees, grasses, weeds, and molds related to where you live. Sometimes you can have other items beyond the normal panel screened at a cost of $35-50 per item.

There are two types of blood tests used for dogs:

  • Enzyme-linked immunosorbent assay (ELISA or EIA)
  • Radioallergosorbent test (RAST)

The ELISA is considered more accurate. There’s a scale of measurement for each item tested which can tell you if your dog has a mild to severe reaction to that item.

This sounds better than it is. The problem is neither blood test is precise because both tests were created for humans, not canines. My experience is that blood tests fall into two extremes: the dog shows allergies to almost everything or nothing.

Imprecise, however, doesn’t mean inexpensive. Blood tests typically cost $300 to $500 depending on where you live.

The benefit of blood tests to your vet is that the vet gets the full cost of the testing: the vet draws the blood and then sends it to lab for analysis.

I’d be leery of a vet that pushed a blood test over a skin test without a recognizable reason; e.g., your dog is on steroid treatment or his skin is too inflamed.

Intradermal skin testing

This is the gold standard for allergy testing and is similar to the way allergy testing is done on humans. Successful identification and treatment of dogs by this method is as high as 75%.

While your dog is sedated, one area of his side is shaved down to the skin and small amounts of antigens are injected. The veterinary dermatologist follows a specific pattern and order so s/he can identify the allergy trigger.

This test is more expensive than blood tests and typically runs $500 to $800. One reason for the expense is that the test must be administered/interpreted by a veterinary dermatologist. Also, no family vet is going to keep a supply of antigens on hand for this test.

This test works best if performed during the season when the allergies are at their worst, and your dog must not have been treated with steroids or antihistamines for several weeks to months before testing. The veterinary dermatologist will provide directions for the testing process.

If you want to see where the money goes, watch this video:


Because of the costs involved, I suspect many dogs that would benefit from allergy testing are not getting them.

The most severe reaction, anaphylactic shock, is life-threatening and requires immediate veterinary help. Those severe symptoms include difficulty breathing, swelling of the face or limbs, seizure, unconsciousness or coma.

If the allergies are mild (paw licking but no bleeding or swelling skin, sneezing, or watery eyes with tear stains), you may want to try Grandma’s remedies (see http://www.toybreeds.com/dogalleries.htm before taking more expensive steps.

Keep in mind that Grandma’s remedies do not include steroids and only over-the-counter antihistamines. If these lesser treatments do not alleviate your dog’s allergies, I would go for skin testing and subsequent allergy shots rather than treatments such as steroids that could have serious side effects.

See also http://www.toybreeds.com/allergytriggers for a list of common problem triggers as well as an explanation of allergy shots and http://www.toybreeds.com/dogallergies for an overview of allergies and a video showing moderate and severe skin problems.

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