In the first lifelong canine diet-restriction study, researchers discovered that Labrador retrievers fed 25% less food than their siblings in a control group had a median life span of nearly 2 years longer. The conclusion among participating scientists: Less food in the bowl adds more—and healthier—years to dogs’ lives. Researchers at the Purina Pet Institute in St. Louis, in collaboration with scientists from several major universities, published results of this 14-year study that shows that a dog’s median life span can potentially be extended by 15% when the dog is kept to its ideal body condition by carefully monitoring food intake. “We all know that obesity, whether human or canine, is bad for health,” says Dennis F. Lawler, DVM, a veterinary scientist who, along with principal investigator Richard D. Kealy, PhD, directed the Purina Lifespan study. “What’s exciting about this study is that, for the first time, we have shown scientifically that by simply feeding to maintain the ideal body condition throughout a dog’s life, we can increase length of life while delaying the visible signs of aging. That’s powerful stuff.”
Lean-Feeding Cuisine
The study began in 1987 at Purina’s pet care center with 48 Labrador retriever puppies from seven litters. “We selected Labs because their life span averages between 12 and 15 years, a medium age span between the small breeds who tend to live longer and the large breeds who tend to live fewer years,” says Lawler. “Also, Labradors are chowhounds and prone to obesity, which made this breed a good candidate for our study.” Dogs in each litter were paired at 8 weeks of age based on gender and body weight. Throughout their lives, the daily care and feeding were managed identically for all 48 dogs. At 3 years of age, the type of food changed for all, from a growth formula diet with 27% protein to an adult formula diet with 21% protein. All dogs were given regular health evaluations to check body fat mass, lean body mass, bone density, and glucose and insulin use, as well as cholesterol and triglyceride levels and many other health parameters.[pagebreak]The only difference: food quantity. One dog in each pair was fed 25% less food per day than its mate. The study, which was published in the Journal of the American Veterinary Medical Association, revealed the following results:
Dogs who ate 25% fewer calories than their littermates maintained a lean or ideal body condition, resulting in a median life span that was 15% (or nearly 2 years) longer than the dogs who ate more food.By age 10, seven dogs in the control group had died, compared with only three lean-fed dogs.By age 13, only one control dog was still alive, as compared with 11 lean-fed dogs.By age 13.5 years, no dogs in the control group were alive, but 25% of the lean-fed dogs had survived.The lean-fed dogs did not require treatment for osteoarthritis until a median age of 13.3 years, fully 3 years later than the dogs in the control group.
These results are significant because this represents the first lifelong study controlling food intake in a large-size mammal, says Richard Weindruch, PhD, a University of Wisconsin-Madison professor of medicine and expert in the diet restriction field. “It is clear that there are a number of health problems frequently associated with overeating and obesity—both in dogs and in people,” explains Weindruch. “From this study, we can extrapolate that large mammals, including humans, can potentially live healthier and longer lives through reasonable diet restriction."[pagebreak]
Food Bowl Tips
Keep your dog fit and healthy by following these tips:
Ask your veterinarian if your dog’s body condition is ideal. If not, work with your vet to set up a weight loss plan to return him to that goal condition.Read the food label for recommended daily portions based on your dog’s weight, and look at the package back for an illustration of a dog at ideal body condition to see if your dog matches up. It’s more important to feed your dog to his ideal body condition than to a certain weight.Feed the dog, not the bowl. Use a measuring cup when scooping the dry food into the food bowl, so you know exactly how much you are serving. Get a smaller bowl if you think it looks too empty.Perform a weekly check on your dog to make sure you can easily feel his ribs. Examine his profile to see if his abdomen is tucked behind the rib cage, and stand over him to see if he has a clearly defined waist behind the ribs.Adjust the amount you serve your dog to maintain ideal body condition. No matter what he weighs, if body condition is at the ideal point, the weight will be acceptable.
Walk This Way
Pair sound nutrition with regular fitness to keep your aging dog in shape. M. Christine Zink, DVM, PhD, an expert in canine sports medicine, recommends that you follow these steps to maximize the health benefits of walking your dog:
Warm up your dog’s muscles by starting with a 5-minute slow pace. Then take a 10- to 15-minute brisk walk, ending with a 5-minute slow pace to cool down the muscles.Keep your dog on a brisk pace for the majority of the walk, so that he trots rather than saunters. This gait exercises both sides of your dog’s body and provides him with a cardiovascular workout.Aim for 20-minute daily walks rather than hour-long walks on weekends. A little exercise every day is better than a lot of exercise once or twice a week.
