What kind of tests were run on the dog?
Thyroid checked?
Skin scrape for parasites?
I'm not a vet but just from looking at your pictures I'd say you are dealing with more than just an allergy and some other form of skin disease with that much hair loss and scaling. Possibly some form of Alopecia.
I would suggest having the dog looked at by a specialist, as in a Veterinary Dermatologist. Your vet should be able to recommend one.
Thyroid checked?
Skin scrape for parasites?
I'm not a vet but just from looking at your pictures I'd say you are dealing with more than just an allergy and some other form of skin disease with that much hair loss and scaling. Possibly some form of Alopecia.
I would suggest having the dog looked at by a specialist, as in a Veterinary Dermatologist. Your vet should be able to recommend one.