Keep Them Warm
We wrote about pet beds in our December "Holiday Tech Gift List for Naughty and Nice Pets", highlighting the K&H Thermo-Kitty Bed and the K&H orthopedic canine heated bed.
If they're outside during milder cold temps, the consensus is that dogs need an elevated, dry doghouse with hay or cedar chips to trap heat in the structure. But if you really want to go all out, you can regulate the temperature inside the doghouse with a heater/AC unit.
Keep Them Hydrated
With the changing temperatures, levels of humidity and artificial heating, dehydration is a common winter problem for animals, so it's more important than ever to make sure your pet always has fresh water available, especially if you're not in the house with them during the day.
There are lots of pet fountains available; we wrote about the aesthetically-pleasing Raindrop Design pet fountain in our automated pets gear roundup, and we have heard good things about the Drinkwell 360 too.
Keep Them Safe
There are a lot of dangers during the winter, from frozen paws to antifreeze puddles to rock salt on the sidewalk, so stay alert. The ASPCA offers several safety tips to make sure your furry friend stays cozy during the season. One tip we learned was to bang on the hood of your car before starting the engine, in case any neighborhood cats have crawled inside to be near the engine's warmth.
They also offer a free PetWeather App for iPhone and Android that displays a three-day forecast to help you determine what will be safe and comfortable for your pets.