Your Dog Is Fat. And You Know What to Do

A pet weight-loss plan, like a human plan, requires some strategizing.

Katherine Hobson's dog Mindy

I knew it was time to do something about my dog's weight when an obedience trainer who hadn't seen her in a year greeted us with, "Mindy! You've gotten so, um, fluffy!" Mindy may have taken it as a compliment, but I knew better. My vet says that because her short legs and long back (she's a dachshund mix) predispose her to disk problems, she really should pare about 1.5 pounds off her current 16.5-pound frame.

The doggie solution is (not surprisingly) a mirror of good weight management in owners: Eat less, exercise more, and—this is key—devise a plan that works with the animal's preferences, says Deirdre Chiaramonte, staff internist and director of the fitness and rehabilitation service at the Animal Medical Center in New York.

On the diet side of things, for example, some dogs are extremely conscious of the volume of their food. "If you short them two pieces of kibble, they'll know," says Chiaramonte. For those pooches, she recommends substituting a low-fat or diet dog food. Be sure you look for one labeled that way, advises Margot Kenly, president of Blue Dog Bakery, which makes low-fat dog treats. You can't read a pet food label the same way you read a human food label; if the label says minimum 13 percent fat, there might be far more than that. If it's labeled as low-fat, the manufacturer has to specify a ceiling on the fat content, too.

With other dogs, you can get away with just cutting back. No need to worry about dipping below the amounts recommended on the bag, says Chiaramonte. Those are calculated for animals that haven't been neutered, and they're often set too high. "We can eat like pigs when we're teenagers and then we can't when we're adults; it's the same for dogs," she says. And watch the treats. Mindy's fave is now baby carrots.

Exercise, of course, is good not only for the dog, but for the owner. If your pooch hasn't exercised in a while, start off by extending a walk by a little more each time, and work up to at least 30 minutes a day. (Some working breeds will require much more—ask your vet or breeder.) Take the stairs instead of the elevator. The Animal Medical Center even has underwater treadmills to help arthritic or very obese dogs exercise safely. (For a look at how a horrifyingly overweight Chihuahua fared on this and other exercise plans, see this story from New York magazine.)

As with people, dog obesity isn't just a cosmetic issue. A 14-year study by Purina found that dogs that maintained an ideal or lean body type lived almost two years longer than their littermates who were heavy. Because it's often hard for owners to notice how fluffy their own dogs are getting, get your vet to weigh in. Nothing can substitute for a vet's assessment, but Pfizer Animal Health, which makes a prescription-only weight-loss drug for dogs called Slentrol (you knew that would happen sooner or later), has a quiz that can at least give you an idea of whether your dog needs to slim down.

Finally, don't expect quick results. Dieting dogs can safely lose between 1 and 3 percent of their body weight a month, says Chiaramonte, which means big dogs that need to lose 15 or so pounds might take a year to achieve their ideal weight. That means Mindy should get her girlish figure back just in time for swimsuit season.