Fashion & Beauty

Do dogs need coats?

It’s 45 degrees out and Willis, a 6-year-old toy poodle, is frolicking in Washington Square Park wearing an orange wool sweater, complete with hood. Whenever the wind picks up, his owner, Lauren Costa, 31, pulls the knitted headgear tight over his furry face.

“I put a sweater on him for anything under 50 degrees,” explains Costa. “I make sure it’s on because I don’t want him to get sick.”

This would be thoughtful of her, except for the fact that dogs never get sick just because it’s cold outside. “A dog is not going to get the sniffles like we do, because there is no cold virus that affects them,” says Dr. Bonnie Beaver, a spokeswoman for the American Veterinary Medical Association. “But wearing a coat can be very dangerous for a dog, especially if it’s a heavy coat and the dog is doing a lot of exercise.”

Miniature dog parkas, sweaters and vests may be adorable — and even seem sensible in the deep freeze of a New York winter — but in fact, vets say, city dog owners who play dress-up could be endangering their pets’ health.

Unless your dog is a Chihuahua or an equally tiny toy pooch with short hair, canines barely feel icy temperatures below 32 degrees, Beaver says.

Even in Juneau, Alaska, where average January lows hover around 20 degrees, dogs almost never wear coats, says Dr. Jesse Webb of the Southeast Alaska Animal Medical Center in Juneau. New Yorkers’ obsession with canine couture is pure madness, he says.

“Just because we feel cold, it doesn’t mean our dogs do,” says Webb. “Maybe if the dog is coming from a very warm climate like Florida, we might recommend it wear a coat for a few weeks to acclimate. But most dogs, even if they just arrived in Alaska, are pretty much oblivious to the cold.”

Try telling that to Kate Wilson, whose terrier Gozi sports a puffy orange jacket at the Washington Square Park dog run. Because Gozi grew up in Palm Springs, Calif., Wilson feels he is afraid of the cold.

“Once in a while I take him out without the coat,” she says, “just to remind him of what it’s like to be naked, and so that he doesn’t lose touch with nature.”

Makeup artist Emi Koizumi puts clothes on her Chihuahua, Apollo, all year long — even in the summer.

“He has very thin skin and doesn’t like to be naked,” she says. “He has a few winter coats but really prefers to wear sweatshirts.”

New Yorkers like Koizumi fuel a national dog-clothing industry that was worth $300 million in 2009, according to market research company Packaged Facts, which releases its findings Monday.

“Households earning more than $70,000 account for more than half of dog-clothes spending,” says analyst David Lummis. (The mean household income in Manhattan is $126,035 — among the highest in the nation.)

West Villager Claudia Schwalb, 57, keeps Elvis, her miniature poodle, snug in a $100 Parierox sweater from Japan, and a “Pierre Cardog” T-shirt.

“If it starts raining, I have a Burberry raincoat he can wear,” says Schwalb. “It’s an Eastern European style, like Borat might wear.”

But Dr. Beaver does not approve. “Owners could be harming the dog if a coat pulls the hair down tight,” she says. “As for raincoats, dogs have gotten wet forever and they don’t seem to mind.”

In fact, some dogs — including huskies and Newfoundlands — regulate their own body temperature with an insulating layer of fur, which lifts off their bodies in warm weather and pulls in close to trap heat when the mercury drops.

Interfering with this natural climate-control system could lead to heatstroke — and, in a worst-case scenario, even death, says Beaver.

“The most important thing is the animal’s welfare,” she says. “If New Yorkers want to make a fashion statement, they can do it with a colored collar.”

But New York dog owners with a fashion passion aren’t heeding vet advice.

“I don’t listen much to veterinarians,” says Schwalb. “I’m sort of akin to a dog Christian Scientist. I follow my impressions from shivering little dogs in the past.”

Lauren Costa simply refuses to believe that Willis doesn’t need a coat. “He has skinny arms and legs and not a lot of meat around his torso,” she says. “I would still dress him in a sweater when the weather is below 50 because there is no way his tiny little metabolism could compensate for such heat loss.”

Upper West Sider Janne Applebaum even admits to dressing her schnauzer, Arthur, on the most mild of days because, she says, the handmade outfits she puts him in, including pants and suspenders, make so many people smile.

“That’s why winter is my favorite season, just because we leave so many smiles in our wake,” she laughs. “I’m just sorry he doesn’t have his sailor outfit on today.”

jsilverman@nypost.com