Thank you for the comments, everyone! I always forget to ask the vet because the visits are quite stressful for us both. My wife thinks he is part Angora, actually. His name is Bailey, since he was the colours of Bailey's and cream when we got him. He's a strange cat; ultra-affectionate towards me, but intensely distrustful of visitors and given to going completely feral in high-stress situations. Yet we've had him since he was a kitten, and I don't know where we went wrong...