Written by Dogoos Editorial · Editorial team
Picture your dog flopped on the floor after a long walk, legs splayed, eyes half-closed, utterly spent. It is a satisfying sight, and it is where the old saying comes from: a tired dog is a good dog. But tiredness is an odd thing to aim for, and the research points somewhere gentler. What a dog gets from a nose-led hour is less exhaustion than contentment. Start with the nose, because it explains the rest.
One veterinary review puts a dog’s capacity for detecting odour at as much as ten thousand to a hundred thousand times ours, a range gathered from older work rather than one measurement, which is why thousands of times more sensitive is the honest way to put it. The olfactory bulb, the piece of brain that handles what the nose sends it, takes up about 0. 31% of a dog’s brain volume against 0. 01% of ours, proportionally some thirty times more. You may have read that smell occupies forty per cent of a dog’s brain.
It does not, and the anatomy papers people cite for it say no such thing. What that machinery reads is structure, not atmosphere. A dog can work out which way a person was walking from about five consecutive footsteps, and lingers over the smells that interest it, so a dog at a lamppost really is establishing who came past and how recently. What it is not doing, as far as anyone has shown, is reading the mood of whoever left the mark. That part is a lovely story rather than a finding.
Which brings us to the sniffari, the walk where the dog sets the pace and the route and stops at every lamppost for as long as it likes. Here the usual advice goes wrong. You will read everywhere that sniffing is calming, that it engages the soothing branch of the nervous system and winds a dog down. In 2026 a research team put ECG halters on 21 dogs through a five-minute scent search, a five-minute control walk and spells of waiting. Heart rate rose for both and was highest during the search, and heart rate variability barely differed.
Their conclusion is the opposite of the folklore: scent work looks like more arousal, not less. The reassuring half is that the searching dogs showed no stress-related behaviours and carried their tails high. That is the arousal of an absorbing job, not of distress. So if sniffing does not sedate a dog, what does it do? It changes how they feel about the world.
Pet dogs given two weeks of nosework, against a control group doing heelwork, were tested on the standard optimism measure, an ambiguous cue that a hopeful dog trots towards and a pessimistic one hangs back from. The nosework dogs approached significantly faster than they had before, and the control dogs did not change. More time using their olfaction, the researchers concluded, makes dogs more optimistic. Not more tired. More optimistic, which is the better thing to hand a dog anyway.
Once you stop chasing exhaustion a whole menu opens up, most of it in your living room or back garden. Scatter feeding is the simplest: instead of putting the bowl down, toss the kibble across the lawn or over a towel, turning a bowl emptied in seconds into a proper search. A snuffle mat asks for the same foraging indoors, and find-it games take it further, where you ask your dog to wait, hide a treat behind a chair leg, then send them off to find it.
No study has ever shown that twenty minutes of sniffing tires a dog more than a run, however often you see that claimed, so enjoy these for what they demonstrably are: absorbing, and good for a dog’s outlook. Chewing earns its place with an honest label on it. A 2025 review found one dog study worth pointing at: fearful dogs did better on a spatial memory test straight after five minutes of chewing, and the harder they chewed the better they did.
The rest of the calming case comes from human gum-chewing research, and the reviewers say plainly that whether chewing reduces stress in dogs remains to be determined. So offer the chew, safe and long-lasting and sized for your dog, but do not promise yourself it is a sedative. Five focused minutes of a new trick or a tidy recall earns its place the same way: most dogs visibly enjoy being asked to think. The aim throughout is a satisfied dog rather than a flattened one, and you can overdo enrichment as easily as exercise.
Owners and trainers describe a consistent picture of a dog who has had too much: a shorter fuse than usual, food left that would normally be gobbled, zoomies that will not settle, restless sleep, no off switch when the house is quiet. Nobody has tested that list. There is no study of the overtired pet dog, and every sign on it overlaps with pain, illness or plain boredom, so treat it as a reason to look closer rather than a diagnosis. Note what you saw and when, tell your vet if the pattern keeps coming back, and a few restful days cost nothing to try.
Age and breed shift the picture, and one popular piece of puppy advice is not merely unproven but backwards. Norwegian researchers followed 501 puppies from 103 litters of Newfoundlands, Labradors, Leonbergers and Irish Wolfhounds and radiographed their hips at twelve or eighteen months. Puppies using stairs in their first three months were more likely to develop hip dysplasia, and puppies getting off-lead exercise in that window were less likely to.
The recommendation that came out of it was no stairs under three months, and outdoor exercise on soft ground in moderately rough terrain. In a big, fast-growing puppy, ration the stairs rather than the freedom. Older dogs take happily to the slow, sniffy version, and it asks little of stiff joints. You will read that it keeps their minds sharp too, which it may, but nobody has tested that in older dogs, so offer it because they enjoy it.
Breed appetite is the part everyone is surest about and the evidence thinnest on: a collie owner will tell you their dog’s appetite for a job is bottomless, and that is kennel-side experience rather than a finding, and one olfaction review notes that some researchers argue breed differences in scenting may not exist at all. The one breed caution with hard numbers behind it is airway disease.
Among 36 dogs given a six-minute walk test, flat-faced dogs with brachycephalic obstructive airway syndrome still had raised heart rates a quarter of an hour later and ran hotter in the upper airway throughout, while healthy flat-faced dogs had recovered by then. It is the airway disease rather than the flat face by itself, but panting is how a dog sheds heat, so a pug who snorts, snores or tires quickly wants short, cool, measured activity and a vet’s ear on that breathing.
Mix the two kinds of walk across the week rather than picking a side: a couple of proper physical outings, with scent and thinking work woven into ordinary moments. Keep the easy days genuinely easy, and if you are unsure what suits your own dog, especially one with a health condition or a joint problem, ask your vet. The flop on the floor was never really the goal. The goal is the dog who is glad to be here, nose full of news, and if that dog then sighs and falls asleep across your feet, take it as a bonus.
Sources & further reading
- When the Nose Doesn't Know: Canine Olfactory Function Associated With Health, Management, and Potential Links to Microbiota — Frontiers in Veterinary Science (Frontiers Media) (2018-03-29)
- The Olfactory Bulb in Companion Animals - Anatomy, Physiology, and Clinical Importance — Brain Sciences (MDPI) 13(5):713 (2023-04-24)
- Canine Olfaction: Physiology, Behavior, and Possibilities for Practical Applications — Animals (MDPI) 11(8):2463 (2021-08-21)
- Functional significance and welfare implications of chewing in dogs (Canis familiaris) — Frontiers in Veterinary Science (Frontiers Media) (2025-03-26)
- Evaluation of infrared thermography and 6-minute walk tests to assess airflow limitation, impaired thermoregulation, and exercise intoleranc — PLOS ONE, 18(3):e0283807 (2023-03-31)