Researchers at Auburn University’s Canine Performance Sciences program, which breeds and trains detection dogs, recently published a paper in the Journal of Applied Animal Behavior about the impact of chewing on dogs’ working memory.
Ethologists, veterinarians, and trainers have long advised humans to give their dogs ample chewing opportunities—and the Auburn scientists found that fearful dogs who’d spent time chewing before attempting a maze performed better than those who hadn’t. But the full results contain subtitles and ambiguities that may leave any dog person with plenty to chew on. Here are the details, plus other experts’ insights on chewing’s importance to dogs.
What happened in the study?
The researchers studied 32 adult Labrador retrievers who were bred for detection tasks and regularly trained for them.
They tested whether chewing helped dogs remember more accurately in which of three buckets a treat was hidden, and if chewing helped them remember the treat’s location after delays of up to two-and-a-half minutes. In a second test, the scientists tried to figure out whether chewing improved dogs’ performance on an outdoor maze.
The researchers wanted to know whether dogs’ level of fearfulness made a difference in how chewing affected them. To determine which dogs were more fearful, they looked at trainers’ responses to the Canine Behavioral Assessment and Research Questionnaire (CBARQ).
The more-fearful dogs performed better on the spatial-navigation task after chewing, while dogs who were less fearful did not. Dogs with a higher bite intensity also performed better on the maze.
What does it mean?
What accounts for this difference? Sarah Krichbaum, Ph.D., one of the study’s authors and a Research Fellow in Canine Performance Sciences at Auburn University’s College of Veterinary Medicine, says: “I believe this is because less-fearful dogs simply don’t need the therapeutic effect of chewing that gives more-fearful dogs a mental advantage.”
There were also fine distinctions in the results. Chewing more frequently didn’t seem to have the impact that chewing more forcefully did—and, even though dogs who chewed more forcefully did better on the initial maze test, the gap between them and other dogs disappeared when they navigated the maze again two weeks later.
There’s a limit to what a single study of a small number of dogs can tell us about dogs in general. For her part, Dr. Krichbaum says that “This study should be replicated in other populations, as it is possible that the enriching effect of chewing was so robust due to the high arousal and reward drive which characterizes this particular population”—the adult Labrador retrievers who were bred and trained for specific tasks.
Should my dog chew more?
It’s hard to make generalizations about dogs from any single study, let alone one that involved a relatively small number of dogs with similar breeding and training. But we can be sure that most dogs benefit from plenty of chewing time.
It seems reasonable to infer that the dogs in this study enjoyed chewing, as almost every participating dog (29 out of 32) spent some time doing so when given the chance. And trainers, behaviorists, and ethologists frequently extol the virtues of letting dogs chew.
When we spoke with Denise Herman, founder and head trainer at Empire of the Dog in New York City, about training puppies to have good mouth manners, she said: “I tell people that their goal for chewing and puzzling toys is three-plus hours a day cumulatively.” Using dog-safe chews can be good for your dogs’ mental health, saving household items from damage and preventing your dog from hurting themselves by chewing unsafe objects.
Dr. Marc Bekoff, an ethologist and the author of Dogs Demystified—who was not involved in the Auburn study—called it “important.” “Chewing is a natural dog behavior, and they need to be allowed to do it to be dogs, just like their wild relatives,” Dr. Bekoff says. “Humans have to provide dogs with the opportunity to chew—so that they can be dogs, and the humans won’t get upset about what the dogs are chewing.”
“I think it is possible,” says Dr. Krichbaum, “that the implementation of chew toys for dogs with certain temperaments (e.g., high fearfulness) could be beneficial for reducing common behavioral problems in pets and shelter dogs, such as separation anxiety or aggression. However, additional research is needed to elucidate these relationships.”