In very cold weather, the pads on the bottom of your dog's feet can take a beating. They may appear dry and slightly cracked. If you notice this, or, better yet, before it becomes a problem, here are some measures you can take:
After each walk, wash off your pet's feet. This will get any ice off them and washes off any road salt that could be causing the dryness.
Trim the hair between your pet's toes; it often collects ice and snow.
If dryness persists, apply petroleum jelly to the pads prior to walking your dog.
In extreme cases, you could buy special boots made of neoprene or similar materials for your pet.
For more information, please read the story How to Help Your Pets Weather the Cold Winter.