Also, it might be difficult now since he's so small, but I would invest in some Ruffwear polar trex when he's older for his feet if you continue living in snowy areas, they're amazing and are really helpful in preventing paw injuries from the cold!

I have also just read your comment about the bunnies. Aussies are prey driven, so I would highly suggest keeping the bunnies enclosed and only out when you can monitor them very closely. Honestly, I wouldn't trust a dog around rabbits, even my dog and he's service trained. Too many things can go wrong in such a small amount of time.