With his feelings for Remus and Sirius, I don't think he'd be too doggy friendly. No, he'd like cats - he moves like one. I see his patronus (if he ever get's over Lily) as a Panther.

Hmmm, that's hard. On the one hand cats are related to Gryffindor's mascot and on the other you have the fact that dogs would probably remind him of both Sirius and Remus. I don't think he'd like either, but if he had to choose then he'd probably go with a...dog. He could train it to bark and growl at both Remus and Sirius. I could see him with large rottweiler

I can def see him as a dog person like a bulldog or a boxer dog something big and manly and it would have to be black.
Cats are too small and girly and not very homely.

More Butch-like

constant reminder of sirius in his room...?