Wild Canines Fast as a Way of Life
Complete or modified fasting is a normal occurrence in the lives of wild dogs, and is beneficial to their health, in part because it puts them into ketosis. In an article for Veterinary Practice News, my friend and fellow veterinarian Dr. Nancy Scanlan writes:
“Wolves, the dog’s closest living relative, are a window into normal dog physiology (before modification by kibbled dog food, dog sweaters and doggie beds). An ongoing study of wolves reintroduced to Yellowstone National Park confirms that they ‘are adapted to … feast-or-famine foraging.’1
When hunting is easy, packs make a kill every two to three days. An elk is consumed in this order: first, organ meats, then major muscle masses, and finally bone and hide. In this case, at the end of the two or three day period, lower caloric value is consumed, and bones are eaten at the same time as hide, including the fur.
This mimics to a certain extent the alternate [high-calorie/low-calorie] day diet used in one type of CRD [calorie-restricted diet]. In leaner times Yellowstone wolves have scavenged mostly bone and hide for several weeks at a time. This is more like a prolonged modified fast.”2
Additionally, as wild dogs age, their ability to catch prey consistently diminishes; they are not successful in catching food every day. Nature built into their system a means of sustaining health through periods of no food consumption by allowing their bodies to burn two fuel sources: glucose (during “feasts”) or ketones (during “famine”).
Ketone bodies (or ketones) are naturally produced energy molecules which occur from the breakdown of stored fat. Ketones are efficiently used by muscle tissue, the heart, eyes and other organs as an awesome fuel source when glucose is in short supply. Research shows ketones readily cross the blood/brain barrier to fuel the brain and in fact, may be the brain’s preferred fuel source.
Like humans, all dogs (wild and domestic) have the ability to utilize either glucose or ketones as a fuel source; think of their bodies as being a hybrid engine, able to use either glucose or ketones for energy.
The year I spent making the Dog Cancer Series documentary, talking to top veterinary oncologists, metabolic doctors and cancer researchers, convinced me that one of the healthiest things we can do for our own bodies (and for our pets) is to occasionally but consistently fire up this innate, healing, metabolic pathway.
Allowing our dogs’ bodies to naturally create and burn ketones has proven to not only be a profound healing strategy for disease recovery (as documented by the astounding success of KetoPet Sanctuary) but is a commonsense approach to intentionally creating wellness through wise lifestyle choices, including fasting.