Hopefully he will go from strength to strength and the even the muscles in his other leg will be built up with the swimming, to help if any more problems occur in the future.
Can't give an opinion on his diet but I'm sure you will go with whatever you are really happy with. I read more and more that a raw diet is good but your vet advises against this for the reason given. Maybe a little bit of raw food could be introduced into his diet and gradually built up, if this is the way you want to go.
Good luck with him anyway.
