Itchy and Scratchy

Well you've seen the shedding and the hairballs that result from it, but when is shedding too much?  We're concerned now that this may be the perfect storm: shedding an overly thick winter coat, food allergies, and seasonal allergies.  At first we just figured, ok that time of year and she was always an outdoor dog till now, so she has a lot to shed right?  Then we noticed Nawny started to bite and scratch a lot, and we took her to see the vet.  It was dismissed as seasonal allergies maybe pollen or grass, especially since we had changed her diet to Orijen a high protein grain free diet.  Usually grains are a good cause of allergies in dogs when part of a staple diet.  So we tried Benadryl... no luck.  In fact we're convinced she may even be scratching more after... albeit groggy and drowsy, but still itchy.  So after trying to stop her when we catch it and tired of her sad looks speaking to us "i know I'm not supposed to but it's itchy..." we are finally doing what we should have done to begin with...  Full allergy blood work.  Nawny goes to get her blood drawn tomorrow... really hope it's not food allergies, as we have a whole lotta Orijen we're gonna be donating.  I know... stupid, we should have tested before we bought a ton. Bugger...