Finding Hidden Food in Nosework Increases Dogs' Optimism

Opportunities to use the nose and make choices in nosework are good for dogs’ welfare.

For dogs, opportunities to use the nose and be autonomous in nosework are good for dogs' welfare.  Photo shows a grey Siberian Husky sniffing
Photo: KM-Photography/Shutterstock

By Zazie Todd, PhD

We all know that dogs like to sniff. Is it possible that providing opportunities to find food in nosework can improve dogs’ wellbeing?

New scientific research by Dr. Charlotte Duranton (Ethodog) and Dr. Alexandra Horowitz (Barnard College) finds that dogs who participate in nose work have increased optimism compared to dogs that took part in heelwork instead.

Importantly, both activities involved perambulation, as well as food rewards as positive reinforcement. The difference is that in nosework the dog has the opportunity to use their nose and to exercise choice in what they are doing.

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.

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20 adult dogs of various breeds took part in the study, including Australian Shepherds, Huskies, Cocker Spaniels, and other breeds/mixes.

Half of the dogs took part in a nosework activity with their owner, while the other half did heelwork.

The dogs took part in a group class with their owner (either nosework or heelwork), then the owner practised at home with them once a day for a week.  Then there was a second class, followed by a second week of practice at home.

Immediately before and after the two weeks of the activity, each dog took part in the cognitive bias training and test.

Each activity was structured so there was some development from the beginning to the end. For example, in the first heelwork class the dog was initially rewarded with a treat for taking two paces with the owner, building up to ten paces. In the second week, changes of direction were included.

Similarly, in the first nosework class, dogs began by finding a hide (i.e. treat) in a box, then in one of three boxes. When they found it, additional treats were added to the box. In the second week, boxes were put on chairs and/or further apart to make it more challenging.

Prior to the activities, there were no differences between the two groups of dogs in the cognitive bias test.

For dogs, the opportunities to use the nose and make choices in nosework are good for their welfare. Photo shows a dalmatian sniffing grass with a dusting of snow
Photo: Sergey Fatin/Shutterstock

At the end of the two weeks, the latency for dogs in the nosework group to reach the bowl was significantly shorter. However, for dogs in the heelwork group, it was no different than in the previous test.

These results suggest that dogs in the nosework group were more optimistic.

Dogs in both groups had the chance to earn food rewards, so why the difference?

One reason could be that in nosework, dogs have a lot of choice in what they are doing, because they can move around the room and the boxes as they wish. In doing so, they are problem-solving, and successful problem-solving makes dogs happy too.

Another reason could be because of the opportunities to use their nose. Smell is the most important sense for dogs, and it is important to provide environmental enrichment that gives animals opportunities to use the most important sense and express normal behaviours.

The scientists explain there are some other possible explanations, although they do not think they are likely. For example, the dogs that did nosework were trained to search with their nose (but remember, the food bowl was empty in the cognitive bias task).
I think another difference between the conditions is the manner of reward delivery – one reward per set of steps in heelwork versus several rewards at once on finding the box containing food in nosework. This is consistent with how these are normally taught. It is possible dogs preferred receiving a 'jackpot' like in the nosework. However, other research shows dogs don't run faster for increased quantity of food, so this is not a likely explanation.

This is a fascinating study and it's great that scientists are looking at what kinds of activities are good for dogs' welfare.

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.

If you are interested in trying nosework with your dog, you can find a list of Certified Nose Work Instructors here. See five fun things to do to make your dog happy today and six ways to entertain your dog indoors for more enrichment ideas. And you might also like my book, Wag: The Science of Making Your Dog Happy

What opportunities do you give your dog to use their nose and make choices?

Zazie Todd, PhD, is the author of Wag: The Science of Making Your Dog Happy. She is the founder of the popular blog Companion Animal Psychology, where she writes about everything from training methods to the human-canine relationship. She also writes a column for Psychology Today and has received the prestigious Captain Haggerty Award for Best Training Article in 2017. Todd lives in Maple Ridge, BC, with her husband and two cats.

Useful links:

Duranton, C., & Horowitz, A. (2018). Let me sniff! Nosework induces positive judgment bias in pet dogs. Applied Animal Behaviour Science.

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  1. I reckon that, as you point out, those are different sets of behaviour. As it concerns heelwork, the dog is asked to perform a certain behaviour (stay by your owner, follow it), while the nosework dog is told to find the box whatever approach it takes to get there.

    It makes a difference to try, fail, go on, and have success, or to simply perform one behavior. I encounter so many human dog teams where the dog is the receiver of signals on which it performs the asked behaviour, but the dog doesn't perform much seeking behavior/exploring behavior. No wonder, it's mostly unwanted when a dog is on its own journey doing rubbish things.

    I guess that's also why adult humen often fail to be explorative/curious: You're supposed to be serious.

    You get what you reward ..

    I often throw one kibble at my blind Labrador. It makes him curious and he gets to find it. He's really like a vacuum searching for the trophy.

    Now where temperatures where below zero at night and the pond in the front yard was frozen, and in the morning the margin thawed, there is a plate floating about. My blind Labrador goes on it, carries around his pieces of everything, with no fear at all, although it's slippery and wobbly! That's what makes me do happy and proud, and that's what's called resilience. Positive psychology can do a lot, as your article shows, to cheer up a dog and make behaviour problems less likely.

  2. I see parallels in your article to basic clicker training (reward for doing as I asked) vs. shaping (where the dog has to figure out what's wanted to get the reward). While clicker training gets his attention (treats!), he's far more focussed and engaged when we're shaping. I'd say he thinks it's a great game.

  3. I would like to offer another reason that dogs are more optimistic. Dogs are very obliging and will pretty much do what we ask, especially if there is a reward in doing so. From my observation with positive reinforcement, and provided a dog is physically able to do so, we can train them to do just about anything. However, when we train dogs to live in our human cultural environment, we are mostly asking them not to act like dogs. Left to their own devises dogs would bark more, raid the garbage, chew what they wanted, go whenever they liked, sleep when and where they wanted, choose how they want to be active and when, and do a lot of humping. Fortunately for us they are willing to fit into our lives and will accept our insistence of how we want them to behave. So, when teaching a dog heelwork we are teaching a human desire (you never see feral dogs doing this), though many dogs do enjoy this type of activity if taught positively. Scent work and treat searches tap into a natural dog behaviour and I believe that it satisfies innate behaviours such as scavenging and territorial information collection which coupled with treats has a very powerful positive affect on the dog's brain. I run puppy classes and in the first class I do a session on the importance of allowing a dog to use its nose and in my behaviour work the first working session always involves taking a dog somewhere on a long line and let it sniff everything it wants. I know from experience with my own dogs it makes them calmer and more content and that playing hunt the treat really helps with puppy zoomies! I am also convinced it makes them smarter and more capable of coping with the world around them.


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