Your dog will demonstrate back pain in various ways. Commonly they will "roach" the back. This means the back will arch upward and round. In so doing they are taking the loading stress off the spine. Your dog will also drop the head and dec eating and drinking.
Chiropractic evaluates the biomechanics of the spine to determine if the cause is a subluxation ( loss of movement w nerve irritation). this is the most common reason and typically goes un treated since your vet is not trained in spinal biomechanics.
Having your dog evaluated by a board certified animal chiropractor is your best approach.
Call dr bruce at 781-337-1180 or email at indekchiropractic@gmail.com