Do dogs need sweaters when it's cold? Plus: Is road salt edible?

Answers to your questions about the news.
Dec. 27 2010 4:44 PM

Do Dogs Need Sweaters?

Plus: Is road salt edible?

Illustration by Mark Alan Stamaty. Click image to expand.

A major blizzard dropped 20 inches of snow on New York City on Sunday night as it made its way up the East Coast. Monday-morning dog-walkers had their animals decked out in sweaters and booties to protect them from the snow and ice. Are warm doggie outfits really necessary?

They can be. Some dogs are bred to handle cold weather. Labrador retrievers and Newfoundlands, for example, naturally grow out their locks in winter for added insulation. They're so good at keeping warm that they don't mind swimming in near-freezing water. But smaller, short-haired dogs are ill-equipped for blizzard conditions. A snug-fitting sweater or coat would make a greyhound or Shar-Pei more comfortable in cold weather, especially if it has a waterproof coating. (Dogs don't perspire much, so Gore-Tex would be a waste of money.)


There are a few other steps pet owners can take to winterize their dogs. During fall and winter, adding one or two pounds of body weight can help. And after a blizzard it might be worth investing in a set of booties like those worn by Iditarod sled dogs. Snow and ice can accumulate between a dog's footpads and create abrasions. The booties prevent new injuries and protect old ones from bacteria and road salt.

There's only so much clothes can do for an animal. No matter what kind of ensemble you put together for your Chihuahua, he's not going to be comfortable in blizzard conditions. Small, short-haired dogs have little insulation and a lot of surface area, so they lose heat rapidly. If a dog shivers furiously, then suddenly stops, he's in serious danger—it's time to get back inside immediately. Frostbite can also develop on the tips of the ears and tail. Sick, older, and postpartum dogs may have thinning hair, which makes them particularly vulnerable to the elements.

Dog-lovers in snowy areas should keep Alaskan huskies as opposed to dachshunds, although the ability to tolerate cold weather also varies among individuals within a breed. Professional mushers test potential sled dogs by letting them sleep in a bed of snow for the night. If the snow beneath them melts, it means their hair isn't insulating as well as it should, and the dog is rejected.

Bonus Explainer: Is the salt that gets sprinkled on roads and sidewalks after a storm edible? No, it might have impurities. While road salt and table salt come from the same mines, the latter undergoes a more extensive process to remove unwanted minerals. To get road salt, miners simply blast the deposits with explosives and crush the bits to the appropriate size. Some impurities are filtered out, but the final product still contains bits of calcium or even trace amounts of explosives. Road salt is also more heavily adulterated with anti-caking agents like Yellow Prussiate of Soda.

Got a question about today's news? Ask the Explainer.

Explainer thanks Cynthia Otto of the University of Pennsylvania School of Veterinary Medicine, Michael San Filippo of the American Veterinary Medical Association, and Bob Traver of U.S. Salt.

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Brian Palmer writes about science, medicine, and the environment for Slate and the Natural Resources Defense Council. Email him at Follow him on Twitter.


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