Allowing Dogs to Sniff Helps Them Think Positively
New research shows that allowing dogs to exercise their noses is good for them.
Posted Feb 07, 2019
A dog's nose is a work of art and they need to use it.
Most dogs like to sniff when they're on the go. It's been estimated that they sniff around 33% of the time when they're moving here and there and this is how they pick up all sorts of information about who's been there, whether a female is reproductively active (we don't know about males), how big they are, and perhaps what they're feeling.
Allowing dogs to take their time getting to know each other’s marks (prior to face-to-face interactions) might therefore help dogs have smoother introductions, giving them more social cues to guide their behaviors. (For more details, see "When Small Dogs Pee, Are They Saying It's Really Not Me?")
The bottom line is simple: Let a dog's walk be for them, and if they're pulling you here and there with their nose pinned to the ground and occasionally snorting, let them do it. I've often thought that not allowing dogs to sniff and to exercise their nostrils and other senses could be a form of sensory deprivation.
Thus, I was thrilled when a woman at a dog park once said to me, rather seriously, that she thought that not allowing dogs to use their noses the way they want could cause serious psychological problems. I’ve thought about this a lot since then. We really don’t know if dogs suffer psychologically when they’re deprived and can’t fulfill their need to sniff and pee if they choose to do so.
Surely, when dogs are rushed along, they don’t get to savor and properly assess and process various odors, and who knows what this does to them. This form of sensory deprivation might be devastating, since they lose detailed information about their social and nonsocial worlds.
Embedded in this thinking is the fact that most dogs are indeed "captive" individuals who we control most, if not all, of the time. “It’s a dog’s life” is sometimes used to describe days filled with laziness and pleasure. All a dog must do, after all, is sleep, laze around, eat, and hang out with friends. What could be easier, especially when someone reliably plops down a bowl of food for you at every meal?
However, the lives of homed dogs aren’t necessarily all fun and games, and living as the companions of humans comes with some important compromises on the part of dogs. Looking at dogs as captive beings isn’t a negative judgment because being “captive” doesn’t mean that a dog is ill-treated or unhappy. Rather, it is the crucial starting point for understanding our relationships with, and responsibilities to, our furry friends—relationships that very often favor us.
Following up on these possibilities—namely, that sniffing might make dogs feel better—I was thrilled to learn of an essay available online for free in a posting on the Companion Animal Psychology website called "Finding Hidden Food in Nosework Increases Dogs' Optimism: Opportunities to use the nose and make choices in nosework are good for dogs’ welfare." This piece, by Dr. Zazie Todd, summarizes a research paper by Drs. Charlotte Duranton and Alexandra Horowitz called "Let me sniff! Nosework induces positive judgment bias in pet dogs" that's in press in the journal Applied Animal Behavioural Science. Currently, only the abstract is available online.
Dr. Todd writes, "The study used a test of optimism—also known as cognitive bias—in which dogs were first trained that a bowl in one location would always contain food, whereas a bowl in another location never did. Then the test involved an empty bowl placed in an ambiguous location, equidistant from the other two places. The idea is that the length of time taken to get to the bowl reflects the dog’s optimism that it would contain a piece of chicken."
In their research, Drs. Duranton and Horowitz studied 20 dogs of different breeds who were at least 1 year old. Ten dogs did nosework during which they were allowed to sniff and search, whereas 10 dogs did heelwork during which they weren't allowed to search with their noses.
The highlights of this paper are as follows: "Nosework reduced dogs' latencies to reach an ambiguous pot in a cognitive bias test; Nosework increases dogs’ positive judgment bias or 'optimism'; Practicing nosework allows dogs to express a natural behavior and be more autonomous; Behaving naturally and making active choices are two key factors in animal welfare; and Olfaction-based activities contribute to dogs’ welfare." The experimental setup can be seen in the figure above and described in Note 1 below.
Drs. Duranton and Horowitz write, "In this study, we tested the effect of an olfaction-based activity on pet dogs’ emotional states. Dogs were first given a cognitive bias test, then practiced a daily, specified activity for two weeks, and finally were given a cognitive bias test again. The activity conducted differed between the groups: dogs from the experimental group practiced nosework, and dogs from the control group practiced heelwork. Results show that the latency to approach the ambiguous stimulus declined significantly after treatment in the experimental group, whereas the latency did not change for dogs in the control group. We conclude that allowing dogs to spend more time using their olfaction through a regular nosework activity makes them more optimistic. By allowing dogs more 'foraging' time, their welfare is improved. Applications for pet dogs in daily life are discussed."
In her summary, Dr. Todd writes, "This research shows it is important to give our pet dogs choices, opportunities to make their own decisions, and chances to use their nose. Doing so is good for their welfare, which is likely why the nosework training led to better results than heelwork."
I couldn't agree more. After considering alternate explanations—including that there were individual differences among the dogs that influenced their behavior, that nosework trains dogs to trot or run faster, and that "dogs did not use olfaction to evaluate the pot, and that the shorter latency to reach the bowl was indeed due to a more positive judgment bias"—Drs. Duranton and Horowitz conclude, "the present study shows for the first time that practicing nosework increases positive judgment bias—levels of 'optimism'—in pet dogs, suggesting that an olfaction-based activity may be a useful tool to improve welfare in owned dogs." I agree with their assessment.
I really look forward to more research on the importance of allowing dogs to exercise their nostrils and other senses. Indeed, one of the Five Freedoms for nonhumans is to allow them the "freedom to express normal behavior by providing sufficient space, proper facilities and company of the animal's own kind."
Anyone who's watched dogs being yanked along on a tether or being interrupted when their noses are pinned to the ground or to different parts of dogs' or humans' bodies knows they really want to sniff. Drs. Duranton and Horowitz show this is true, and I keep thinking about not allowing dogs to exercise their senses can be a form of sensory deprivation. And, now, we know that it might indeed influence their mood. Dogs speak with chemicals and pick up a lot of information from sniffing the mouths, ears, bodies, groins, and butts of other dogs. Even if some people don't like their dog engaging in these acts, they're 100% dog-appropriate and they need to be allowed to do them.
Stay tuned for more research on how dogs sense their world and the importance of letting them be dogs and to sniff to their nostrils' content.
Setting of the Cognitive Bias Paradigm: The dog sits between the owner’s legs while the experimenter put the bowl at one of the three locations, 3m away from the dog. The two bowls at the side represent positive and negative locations (side counterbalanced across dogs) and at the center is the ambiguous location (only for the test trial).
Duranton, C., & Horowitz, A. (2018). Let me sniff! Nosework induces positive judgment bias in pet dogs. Applied Animal Behaviour Science.