When you look at the label on the bag, it will list a numeric fat %.
Like Sabiís Mom emphasized, hydration is really important. If I was feeding an outdoor dog dry food through the winter, Iíd float the kibble in warm water and let it soak in before feeding. I donít keep my dogs outside, but for the animals I *do* have outside during the winter, keeping liquid water available is one of the biggest headaches.
If youíre getting into the 30ís and below, youíll want to make sure you have a way to provide water that doesnít freeze. There are lots of different electric buckets and bowls. Be careful with cords and outlets, and make sure you check frequently to make sure itís working and not popping the breaker. I test the ends of the extension cords that run to the waterers with a small night light before big storms, since it isnít always easy to see thereís a problem until the water is suddenly frozen solid.