I think RCVS is just the Royal College of Veterinary Surgeons...so the main oversight licensing board.
The Certificate in Advanced Veterinary Practice is a self study post-graduate continuing education whatsit. Not specific to any one thing from what I can find.
If he seems amenable, you might ask to be passed on to someone in the building for whom torts is more their thing. lol
As to what your pet needs, I'm afraid no one on the internet can really say with certainty. Opinions are plentiful. But every caregiver has to make their own decisions.
I know your absolutely right and I have to make these decisions but I kinda just want you to hop on a plane and come deal with it for me. Sorry about that .