It depends upon the breed, says Verdino. Some breeds—like huskies, certain shepherds, and mountain dogs—are bred for cold weather, and they really don’t ever need a sweater. “They can be outside for longer periods of time; they have fur on the bottom of their paws that cover most of the pads.”
But many dog breeds aren’t built for arctic temps. “Smaller dogs or shorter-haired dogs may [need coats or sweaters] if the temperatures are getting very cold or if they're going to be outside for a prolonged period of time.”
That raises the question: What’s a prolonged period of time? “The rule of thumb I use: If you’re wearing a light jacket and you went outside, as long as you could comfortably stay outside is about as long as they can stay outside. If you’re wearing a down parka, a winter hat, and gloves, you might be OK, but your dog might not be.
“Generally speaking, if the weather is below freezing, walks should be somewhat minimal—unless, again, they're a mountain breed or they have some kind of booties, clothing, or other protective gear.”
The consequences are real. “Dogs can get frostbite,” Verdino says. “Any prolonged exposure of tissue—skin, paws, exposed belly—to sub-freezing temperatures can cause frostbite. It can be dangerous. I've seen dogs lose limbs because of it. Every dog should have adequate shelter. I'm not a proponent for leaving any dog outside in sub-freezing temperatures without a heat source for that reason.”
Do your research as to the best coat for your type of dog depending upon his breed and size. Make sure your follow the measurement guidelines for each coat designer. We’re digging the Kurgo Loft Dog Jacket and Reversible Dog Coat ($31.49; Amazon.com); Django’s Reversible Puffer Cold Weather Coat for small- and medium-size dogs ($48; Djangobrand.com); and, for the New Yorkers out there, Royal Animals fleece-lined water-resistant NYPD or FDNY coats for small- to medium-size dogs ($39.99).