The endurance benefits of feeding a high-protein, high-fat diet to working or sporting dogs are undeniable. I like to feed a super-premium 30/20 performance blend food. Some guys feed a performance food during hunting season, others give their dogs a high-protein performance food year-round -- whatever you choose, these diets help to keep our dogs running. Now research suggests that certain diets can also improve a dog's ability to smell. (Hat tip to the excellent Living With Bird Dogs blog for the find.)
Researchers at Cornell College of Veterinary Medicine rotated three different diets between a group of 17 detection dogs over an 18-month period: a high-end performance food, a regular adult dog food, and a regular food diluted with corn oil. They found that the dogs performed better during exercise and detection tests when eating a diet low in protein and high in fat. They believe this type of diet helps dogs to improve detection by decreasing the time it takes to lower a dog's body temperature after exercise.
"If you're a dog, digesting protein raises body temperature, so the longer your body temperature is up, the longer you keep panting, and the harder it is to smell well," said Joseph Wakshlag, Associate Professor of Clinical Nutrition, in a news release.
Dogs on the corn oil diet showed the most improvement. The diets were structured to have the same 57 percent of energy from fat, but the corn oil diet had far less protein: 18 percent versus 27 percent.
"Corn oil has lots of polyunsaturated fats, similar to what you'd find in a lot of nuts and common grocery store seed oils," said Wakshlag. "Past data from elsewhere suggest that these polyunsaturated fats might enhance the sense of smell, and it looks like that may be true for detection dogs. It could be that fat somehow improves nose-signaling structures or reduces body temperature or both. But lowering protein also played a part in improving olfaction."
But don't go out and change the food right away. This study only used law enforcement detection dogs -- where quick recovery and acute sense of smell are required -- not sporting breeds where endurance is a necessity. Even the study authors cautioned that "high performance" depends on what your dog is doing.
So where do sporting dogs fall on this matrix? Guess it depends on your particular style of hunting. I could see a retriever who spends a lot of time between retrieves in a duck blind perhaps needing a little less protein. I'm not sure I could see the same for an upland dog or hound, where long periods of running and activity are the norm. If nothing else, this study will add one more facet to the never-ending debate over what, how, how much and when to feed your dogs.
