To choose the right size winter coat for your dog, measure their neck, chest, and length. Compare these measurements to the sizing chart provided by the manufacturer to find the best fit.

Mara Peverini's 10-year-old Chihuahua, Layla, in one of her winter outfits. On cold days in Grand Rapids, Michigan, Layla wears a sweater, a puffer jacket, boots and a neck warmer.

Winter coats are smart. In parts of the U.S. with brutal winters, like New England and the Upper Midwest, dog owners should invest in a coat for their dog, veterinarians say.