Dog with blisters everywhere

I've got a 7 year old golden doodle, for the past few years hes had itchy skin and scratches a lot but in the last year he's started getting blisters all over his body, some of them are really big, like thumbnail big. They seem to be full of clear liquid and hes got red irritated skin under them. I asked the local vet but he wont answer me without a biopsy which I cant afford. Help please.

[Aleda M Cheng, D.V.M., C.V.A]

Sorry I can't help you with this because a biopsy is absolutely necessary.  Skin lesions are difficult to diagnose without additional diagnostics.  Many lesions are great immitatiors.  A histeocytoma can look like a mast cell tumor and visa versa.  Your vet could perform a fine needle aspirate which is less expensive than a biopsy and may be able to give you an answer.  Additionally, your vet may have a Care Credit program.  Care Credit is an interest free credit card (if you qualify) which can only be used for medical or veterinary bills.  It enables you to pay off high bills at your own pace.