FDA approves first canine diet drug

A moment on the lips, a lifetime on the hips. It turns out that adage applies to dogs as well as people.

That humans aren't the only species experiencing an obesity epidemic was underscored in 2003 when the National Academies' National Research Council declared that one of every four dogs and cats in the Western world is overweight.

Soon, however, veterinarians and dog owners will have a new weapon in the fight against canine obesity: Slentrol. Pfizer Animal Health in early January announced that the medication had been approved by the Food and Drug Administration, and the drug would be available through veterinarians by prescription starting this spring.

As the only government-sanctioned weight management drug for dogs, Slentrol is being heralded by Pfizer as a "significant milestone" in the treatment of canine obesity. Data indicate that as many as 17 million dogs in the United States are overweight or obese. Overweight dogs are susceptible to a number of health problems, especially joint ailments and respiratory tract disease.

Slentrol, administered orally once a day, decreases appetite, thereby reducing food intake and making it easier for dog owners to develop healthier feeding behaviors and attitudes, according to Pfizer. The company points out that Slentrol should not be used alone but as part of an overall weight-loss regimen.

"Veterinarians will now have the additional option of using Slentrol in conjunction with diet and exercise," said Dr. S. Kristina Wahlstrom of Pfizer.

While it isn't yet clear which patients will benefit most from Slentrol and under what circumstances, some veterinarians see potential in a fat-fighting drug. "We can do better in treating obesity in dogs, and having more tools is a good thing," said Dr. C. A. Tony Buffington, a diplomate of the American College of Veterinary Nutrition and professor at The Ohio State University College of Veterinary Medicine.

Primary beneficiaries of Slentrol may include overweight dogs unable to exercise as a result of injury or other health problems. Elderly or disabled persons who can't sufficiently walk and play with their dogs could also see their pets benefit from the medication.

In many cases, overweight patients are helped by dropping just a few extra pounds. "When we're talking about weight loss, we're talking about reducing 10 to 15 percent of body weight," Dr. Buffington explained. "We're not talking about turning a hundred-pound animal into a 50-pound animal; we're talking about taking it to an 85-pound animal. Often, that's all that's necessary."

Canine obesity, similar to human obesity, generally has less to do with genetics than eating too much high-calorie food and a sedentary lifestyle, Dr. Buffington added.

It isn't all that surprising that a pet will pack on extra pounds if its owner has a hectic schedule, poor eating habits, and doesn't exercise. Moreover, the perks that come with being man's best friend include access to table scraps, heaping portions of food, and even the occasional fast-food treat.

"We do, indeed, consider our companion animals as part of the family, so we basically treat them the way we treat ourselves," observed Dr. Richard P. Timmons, director of the Center for Animals in Society at the University of California-Davis School of Veterinary Medicine. "If we don't demand that we take care of ourselves physically in terms of exercise and watching what we eat, we're going to do the same thing with our pets."

Dr. Timmons sees definite benefits of a weight-control drug like Slentrol, but he worries clients may think of the medication as a panacea that will magically cure obesity without the owner having to make necessary changes, such as feeding the dog less and providing it with more exercise. This lack of interaction between the dog and its owner, ultimately, weakens the human-animal bond, he said.

"If people do look at this as a shortcut to weight loss, it could actually undermine that relationship they have with their pet, which is nourished by the interaction they will get when they're exercising with them," Dr. Timmons said.

Managing a pet's weight can be a sensitive subject for pet owners, and veterinarians often tread lightly when talking to clients with obese pets—especially if the client is also overweight. Further complicating the matter, food is often seen as a form of love, so telling a client that treating a canine companion to a McDonald's cheeseburger once a week isn't good for the pet may not be well received.

"We tell owners there are other ways you can enjoy your dog's company, like taking it for a walk, instead of feeding it," Dr. Buffington said. "And you might feel better, too, by getting your mind off your life and enjoying your animal."

Dr. Timmons suggested addressing the client in terms of the pet's well-being. Don't say fat is bad, he said, but focus instead on the potential problems the pet may experience if its weight isn't brought under control. "As long as you focus on the well-being of the pet, clients are, in general, perfectly willing to pay attention," he said.

Veterinarians also need to remind clients that the dietary needs of dogs and people are fundamentally different; many people don't realize that the caloric requirements for dogs vary. Giving half a fast-food hamburger to a small dog might provide the animal with enough calories to last up to five days, Dr. Timmons said.

"One of the biggest challenges to a veterinary family practitioner today is to be able to educate pet owners about what the real needs are of this companion animal that is sharing their lives," Dr. Timmons said. "You have to let the people know their needs are different."

Both Drs. Buffington and Timmons stressed the need for veterinarians to communicate clearly about how Slentrol figures into a pet's overall weight management. This goes for possible adverse side effects, too. Pfizer states that, while Slentrol is well-tolerated, the most common adverse effect is vomiting. Dogs may also experience diarrhea, lethargy, or anorexia.

The ultimate therapy for obesity is prevention, according to Dr. Buffington, and the way to prevent obesity is to educate clients with young, growing dogs. Owners should be taught that their pet needs to be fed in accordance with a body condition score, the same way that people judge their own food intake, he said.

Owners should also understand that dogs are there to be enjoyed, so even if it's taking them for a walk or playing fetch, the point is to stay active. "You don't need to go out and get sweaty; you just need to get out," Dr. Buffington said. "As a profession, we can do an even better job than what we're doing at getting that message across."