Dogs and food allergies

QUESTION:

How are food allergies diagnosed?

answered by Randy Kidd

ANSWER:

Reliable diagnosis of allergies, especially food allergies, is far from an exact science. Neither the skin tests which inject antigens into the skin and look for reactions, nor ELISA (enzyme-linked immunosorbent assay) or RAST (radioallergosorbent) tests which detect antigen-induced antibodies in the dog's blood, have proven to be accurate or reliable--false positives and false negatives are common (again, especially when used for determining suspected food allergies).

If food allergies are suspected, a more accurate test is the food elimination test, but this is not the easiest of tests to perform either: a) Most foods contain multiple ingredients and it is almost impossible to isolate the one offending food source. b) Many food sources (corn, for example) are found in a great number of foods, oftentimes hidden as filler. c) Since it takes four to eight weeks to eliminate a food source from the dog's system, the total food source elimination testing needs to continue for at least this long--far too long for most folks (or their dogs) to endure.