Two big, black dogs with perky ears and tongues wagging sit in a tall, dry grass field.

Dietary Restriction and Aging in Dogs


Can we really extend lifespan and healthspan in dogs?

This is the first question we at Loyal are usually asked when we describe our mission to give dogs and pup parents more healthy, good-quality time together. While we can’t predict whether specific drugs or other treatments will work until we’ve done the science to test them, we know that healthspan and lifespan can be extended in dogs because it’s been done!

Dietary restriction is defined as a reduction in calorie and nutrient intake without malnutrition. It has been demonstrated to reduce the occurrence of disease and increase lifespan in multiple studies involving many different species, from yeast to fruit flies, mice to monkeys, and of course dogs.

One long-term study* in Labrador retrievers paired littermates by sex and weight and then randomly assigned one to unrestricted feeding and the other to a calorie intake 25% less than it’s paired littermate. In order to avoid obesity in the control dogs, at about 3 years of age the protocol was changed so these dogs were fed to maintain an optimal body condition rather than ad libitum, but the calorie-restricted dogs were still fed 25% less than their paired littermates ate. The study ran until the last dogs died.

The calorie restricted dogs had a medium lifespan of 13 years, 16% longer than the 11.2 years in the control group. Calorie restricted dogs also developed arthritis 1.5 years later on average than the control dogs. Some dogs developed cancer in both groups, but the average age of death from this cause was 2 years later in the restricted calorie group (11.6 years vs 9,7 years). Similar or even better results from calorie restriction have been seen in other studies and other species.

While sustained calorie restriction is not a practical means of extending healthspan and lifespan in companion dogs, we have learned a lot about the physiologic changes this method produces and how these reduce disease and mortality. This knowledge will hopefully lead us to effective therapies to mimic the benefits of dietary restriction and give pup parents and their dogs more time together. The Healthspan study is the first of many steps we at Loyal are taking to make that dream a reality.

*Kealy, RD. Lawler, DF. Ballam, JM. et al. 2002. “Effects of Diet Restriction on Life Span and Age-Related Changes in Dogs.” Journal of the American Veterinary Medical Association 220 (9): 1315–20.