I'm hoping that you are giving gabapentin three times a day; it's hard to tell from your comments whether the drug is only given at night. Please read the information on Clare Rusbridge's site about medication options - I fear that you don't have correct and up-to-date information on medications and dosage recommendations. Gabapentin effectiveness only lasts from 6-8 hours. Scratching/biting as you describe is a clear sign of the typical response to pain in SM dogs - and your vet and neuro seem to be confusing this with itchiness.
Originally Posted by ilovemochi