I first began thinking about a product like Sustain when I was hunting with my pointing dog, Clem, in the White Mountains north of Fairbanks. We were hunting rock ptarmigan and each hunt covered 20 or more km up and across some steep ridges. I was carrying some maltodextrin with me and I would stop and give him some every 30-45 minutes in a squirt of water from a water bottle. He hunted eight hours in that terrain and even found a covey of willow ptarmigan within 200 m of the truck in our last few steps of the hunt. This was the first time I had tried this in a hunt and was very impressed with Clem's stamina. When I returned home I did a study with our sled dogs where we walked them on an exercise wheel for two hours (about 25 km) and stopped every 30 minutes to give half of the dogs water and then other half of them the same volume of water mixed with the current Sustain formula. We found the dogs accepted the water plus Sustain well and this group maintained their blood glucose (sugar) concentration at pre-exercise levels while those given just water had a significant drop in their blood glucose levels.

When we think about causes of fatigue in working dogs, we need to think of what fuels the muscles and what fuels the brain as both are essential for optimal performance. While most hard working dogs rely on fat as their primary fuel, fat burns in the flame of glucose. In order for dogs to use fat optimally, the pathway which does this requires the presence of intermediates that can only be replaced by sugars. If these intermediates become depleted, the muscle can no longer generate energy efficiently from fat. This is one reason it is important to keep blood sugar levels from falling too low during exercise. The other, perhaps more important reason, is that the brain relies on glucose as its main source for energy. If blood glucose levels drop significantly this can affect cognitive function and other central functions like scent perception and attitude. Sustain is an easy to use solution to these problems. Used as directed it will help your dog maintain their endurance and their mental capacity throughout a long day in the field.

Dr Arleigh Reynolds är veterinär och specialist inom utfodring och på arbetande hundars fysiologi. Han har doktorsgrad i båda ämnena och har tävlat i slädhundskörning på elitnivå i Alaska, samt är en passionerad jägare.