Weight gain for animals can be an issue in the winter since owners most likely aren't walking them as much as they did in the warmer months. Having something to keep them busy, such as busy feeders or puzzle toys for dogs, and making sure they aren't getting any extra food/treats on the side may help.
If pet owners put salt down for the ice on their sidewalks, please wipe the pet's feet when they come in. It's not toxic to dogs but can cause some stomach upset.
Also, remember that if it's too cold for us humans to be outside for extended periods of time, its too cold for our pets to be outside very long too!