If his hair was rough before you shaved it, then I would say there is some terrier in there. Are you in the UK? If so then probably Jack Russell. It is quite a common cross and a lovely mix. I know a few 'Jackahuahuas' and they seem to inherit the best parts of both breeds. Yorkie x Chi mixes are also quite common.
But if he has a coat problem, it could be that making his coat look rough. Very cute pup though either way.