Are they barking up the wrong tree-hugger?

Thanks for killing the planet, dog owners.

Well, that’s a rough paraphrase of a New Zealand study that claims a medium-size dog leaves a larger ecological footprint than an SUV.

In “Time to Eat the Dog? The Real Guide to Sustainable Living,” authors Robert and Brenda Vale argue that resources required to feed a dog – including the amount of land needed to feed the animals that go into its food – give it about twice the eco-footprint of, say, building and fueling a Toyota Land Cruiser.

Noting that a cat’s pawprint was roughly equivalent to a Volkswagen Golf’s, the weekly magazine New Scientist ( www.newscientist.com) asked an environmentalist at the Stockholm Environment Institute in York, U.K., to independently calculate animals’ environmental impact.

The study apparently didn’t take into account the emissions of either the SUV or the dogs.

“If you look at a large-size dog, they can live 10 to 14 years, and it certainly wouldn’t surprise me,” Don Jordan, director of the Seattle Animal Shelter and President of the Washington State Federation of Animal Care and Control Agencies, said of the study.

“There’s a lot that goes into manufacturing and producing food to care for dogs during the course of a life.”

Short of eating the dogs, what should be done about these four-legged eco-Hummers before they kill us all?

“If, in fact, this is true … I would think that pet owners would look at the manufacturing process for the items they’re buying for their dogs,” Jordan said. “I’ve seen every year the boutique shops for dogs start to sprout up, whether it be bakers or clothing stores or treats or stuff.”

Clark Williams-Derry, chief researcher at the Sightline Institute, a nonprofit sustainability think-tank in Seattle, scoffed at the findings.

“When I saw the study I ran some quick numbers,” Williams-Derry said. “The average dog has to eat at least twice as much as the average person for this to be right. People are just heavier than dogs so, I just had to scratch my head at that.

“It doesn’t mean dogs don’t have a big impact,” he added. “But I view it with a healthy dose of skepticism.”

At The Bullitt Foundation, which is devoted to environmental preservation, Steve Whitney said: “I guess in a perfect world the real cost of our consumer products would be reflected in the price we pay and our decision about our pets and health would also reflect the cost so we could make rational decisions about it.

“I suspect benefits derived from companionship of our animals, while difficult to quantify, would also be part of the equation.”

If one were to really tackle the eco-footprint problem, Whitney said, “I don’t think dog ownership would be the place to start.”