My vet checked for mites,...

Question
My vet checked for mites, ringworm, fleas and those types of things.  He
was negative for all of these things.  If it is an allergy, what types of
things might he be allergic to? foods or home type things like cleaners?  

Answer
There are many classes of allergens.  Many times dogs are allergic to housedust mites that live in the carpet and on furniture.  Indoor dogs may also be allergic to molds that are in the carpeting and on the wet ground during spring and fall.  Of course during spring and summer, all of the tree pollens and grass pollens enter into the allergy equation, too.  Your vet can run an allergy test using a blood sample to see if your dog has any sensitivities to any of these allergens.