Our understanding of the nutritional needs of hard-working canine athletes has taken a quantum leap forward in the past 10 to 15 years, and much of the research that's powered this advance has been conducted by Dr. Arleigh Reynolds. A senior research nutritionist for Purina and faculty member at the University of Alaska Fairbanks, Reynolds was for many years one of the top sled dog sprint racers in the country, with multiple North American and world championships to his credit.

We recently caught up with Reynolds, who's also an avid hunter, to pick his brain about some easily followed dos and don'ts to help our gundogs perform to the best of their ability when the birds start flying.

Choose the Right Food

"The most important 'do,'" says Reynolds, "is feeding a high-fat, high-protein performance diet, like Purina Pro Plan Sport, year-round. It gives your dog such a huge conditioning advantage over a dog fed a maintenance diet that it's almost like cheating. Because it's so nutrient- and calorie-dense, you don't have to feed as much, but you do have to watch your portion control."

Watch the Weight

That brings us to Reynolds's most important "don't," which is to keep your dog from gaining additional (and unnecessary) weight during the off-season. "You don't want your dog to be too thin," notes Reynolds, "but if anything, he should be slightly lean."

Reynolds acknowledges that Labs, because of their unique body type, can be tough to evaluate in this regard. "They tend to look heavy even when they're in great shape," he says. Reynolds's test for Labs is to run his hands down the dog's back. "You should just barely be able to tell that the vertebrae are there," he explains. "But if they're mounded with fat, your dog is overweight."

Feed at the Right Time

The timing of feeding is another area in which our understanding has grown significantly. Noting that the optimum time to feed is 24 hours before exercise, Reynolds's advice to gundog owners is to feed as soon as possible at the end of the day's hunting-but only after the dog has completely cooled down.

"If you feed while your dog's still panting," he warns, "you're putting him at high risk for bloat, which is always serious and can be fatal."

Another risk factor for bloat, says Reynolds, is feeding in the morning before hunting-one of a host of reasons why, as counterintuitive as it may seem, you're not doing your dog any favors when you feed him in the morning. Basically, you're putting food in his stomach that he won't be able to utilize during the time frame in which you need him to utilize it.

If you're looking for a testimonial to the efficacy of this once-a-day, never-in-the-morning feeding regimen, it would be hard to beat the glittering record Reynolds's own dogs amassed in sled dog competition, where a second or two per mile makes all the difference. There's this, too: out of all those dogs-some one thousand, all told-Reynolds's dogs have never had a single instance of bloat.

Give Your Dog a Boost

This brings up the question, much discussed in the gundog camp, of whether there's anything you can give your dog that will provide a mid-hunt boost over the course of a long day afield. The scientific consensus is that products high in maltodextrin, a complex carbohydrate, fill this bill splendidly; the bad news is that dog-specific maltodextrin products have been inconsistently available at best.

Thankfully, Reynolds notes that there's a maltodextrin-rich product in gel form, called GU, that, while designed as an energy supplement for human endurance athletes, provides similar benefits to their canine counterparts.

"Dogs seem to like the vanilla flavor best," Reynolds reports. "It comes in a triangular packet; you tear off a corner and squeeze the gel right in the dog's mouth. You'll get the best results if your dog is able to rest for at least half an hour before you start hunting again, and it also works well when given at the end of the day as an aid to post-hunt recovery."

Reynolds notes that the formula for administering maltodextrin to dogs is one to two grams per kilogram of body weight, meaning that a couple of 1.1-ounce (31-gram) packets of GU will satisfy the daily requirements of even the stoutest Lab or Chessie.