I have two dogs, both are sensitive to things, one has environmental allergies. She didn’t wind up doing testing, because I could tell her when my dog seemed to have the strongest reaction. It was always outside while sitting or laying in the grass. My dog is allergic to the great outdoors. He is now on an allergy med and it’s not all that expensive. I’ve heard some people just use 12.5mg of benadryl and at times, the vet has suggested that for my other dog. I would call the vet, tell them you believe it is allergies but need to keep the cost down – we all know that money is tight and vet bills can really go sky high, with a lot of testing. Knowing as many “triggers” to your dogs allergies, is important, it really can answer a lot of questions and eliminate those pricey tests.