I've mentioned this briefly before, but if you are going to have your dog walking on tough terrain, in snowy conditions, or on hot pavement, you should try to avoid damaging their paws so they don't wind up needing to be carried like this guy, or worse. You also don't want the dogs to get their paws damaged by salt used to melt snow or ice if you live in snowy areas.
How to do that? I think the best way is to use Musher's Secret!
This is a great description of what the best choice for dogs is, especially if the dog doesn't like dog boots: Musher's Secret!
Musher's Secret is basically a paw wax, that does a good job from keeping slush, ice and snow from sticking to the toes and fur. The wax also keeps the pads soft. It's a really great product, and does a really great job of preventing your dog from getting injured unnecessarily.
To apply it, just do as he does from 5:30s on! If you want to use it, check out his full review.