The dog aging project: translational geroscience in companion animals

Abstract

Studies of the basic biology of aging have identified several genetic and pharmacological interventions that appear to modulate the rate of aging in laboratory model organisms, but a barrier to further progress has been the challenge of moving beyond these laboratory discoveries to impact health and quality of life for people. The domestic dog, Canis familiaris, offers a unique opportunity for surmounting this barrier in the near future. In particular, companion dogs share our environment and play an important role in improving the quality of life for millions of people. Here, we present a rationale for increasing the role of companion dogs as an animal model for both basic and clinical geroscience and describe complementary approaches and ongoing projects aimed at achieving this goal.

Figure 1. Age is the greatest risk factor for death from many diseases

Fold change in risk of death between ages 40 and 90 is shown on a logarithmic scale for six major causes of mortality in the United States. Death rate data from the US Centers for Disease Control and Prevention 2010.

Figure 2. Dogs display variation in size and longevity

Typical lifespans and body weights are shown for four different breeds of dogs. In general, mixed breed dogs will have a longer life expectancy than purebred dogs. Great Dane and Chihuahua photos from Wikipedia. German Shepherd and Keeshond photos credit Tammi Kaeberlein.

Figure 3. Design of the current short-term rapamycin intervention trial

Dogs must weigh at least 40 pounds and be at least 6 years old at time of entry into the study. If no significant pre-existing health conditions are detected at the first exam, dogs are randomized into either placebo or one of the rapamycin treatment groups. Red indicates the 10 week period during which the dogs receive either rapamycin or placebo. Dogs receive the same generic rapamycin (sirolimus) pill that is provided to human patients. *Serum and feces are collected at each appointment for future metabolomic and microbiome analyses and for quantitation of circulating rapamycin levels.