Dermatology - Allergy Testing and Immunotherapy
There is no such thing as a test that tells us, yes or no, if a patient has allergy. This yes-or-no diagnosis is made solely with the pet’s physical exam and history. Put another way, if a pet owner is wondering if their pet has allergy, the diagnosis cannot be made with a test; the diagnosis is made with the physical exam and history.
If we do allergy testing, it is with the assumption that the pet is allergic. The test is an effort to try to find out what the pet might be allergic to. There are two basic test options: environmental allergens and food allergens. Environmental allergens include house dust, molds, and pollens from grasses and trees and weeds. Food allergens include a long list of basic ingredients of pet diets.
There are two types of allergy tests: skin tests and blood tests. For many years, skin tests were considered the gold standard, but blood tests have improved to the point where, at YVC, we consider them the best allergy testing option. Neither skin testing nor blood testing is 100% accurate. Also, a pet’s allergies can change over time; what a pet is allergic to today might be different from what it is allergic to 1 or 2 or 3 years from now.
When we have environmental allergy test results, an owner then has the option of having immunotherapy (allergy desensitization medication) formulated for their pet. At YVC, this service is conveniently provided by the allergy testing laboratory that performs the test. Immunotherapy is available as daily shots or oral drops. Immunotherapy is not 100% effective; realistically it is closer to 75%. Side effects are possible, including some that are severe enough that they require discontinuation of the treatment. Additionally, as mentioned previously, a pet’s allergies can change with time, so re-testing is sometimes necessary.
When we have positive food allergy test results, an owner has the option of feeding a limited ingredient diet that does not have the foods indicated as potential allergens, or a generally hypoallergenic diet. There is no immunotherapy option for food allergens. Food allergy tests are probably about 75% accurate. For these and other reasons, at YVC we consider hypoallergenic diet trials to be a better option for food allergy testing.
Ultimately allergies are a chronic and frustrating issue that many clients, their pets, and the doctors trying to help manage clinical signs have to deal with. As their prevalence grows, so do testing and treatment options. There is no one-size-fits-all solution to testing or treating. At YVC we take a comprehensive approach to managing patients, allergy testing can be an intergral part of care for patients but is no more important than any of the other pieces.
