Our English Setter Griz (5 years old) is 12 days post-op. He had a hind limb amputated due to aggressive connective tissue sarcoma. I know it hasn't been very long yet, but we are dealing with pretty severe phantom pains and I worry about how long it might take to get better. He started out on Rimadyl and Tramadol, did well for 3-4 days, and then started having screaming episodes at night. It increased in incidence over 3 nights, and then started happening later the next day (7 days post-op) once his meds started wearing off. He spent that night at the vet's on injectable morphine. The vets added Gabapentin and Vicodin to the Tramadol, all 3x/day, and Rimadyl (2x/day). The first few nights went pretty good, and last night he woke up screaming again at 4 am (last dose of pain meds was at 9 pm) and was hard to calm down. The vets have not come across pain issues this severe until Griz. The site is healing well, no obvious cause from that. I understand it takes a while for the brain to re-wire, but we are getting desperate because we don't seem to see any improvement without the heavy meds, obviously we can't keep him drugged up like this forever. 

What are your experiences with phantom pains, how did you manage it, how long did it take to get better?

TIA