Sleep — Look at How He Sleeps First

1 How much a dog sleeps: what studies found

There is no single reliable number, and a dog does not sleep in one stretch. A review (Niinikoski and Rajamäki, 2026) says dog sleep is polyphasic: sleep cycles are not linked back-to-back into one long period, and a cycle lasts on average 20 to 56 minutes. Most sleep is at night, but dogs also sleep during the day, waking in between (Schork et al., 2022). Here is what studies measured or reported:

In the first study owners estimate the sleep and no device measures it, so owners may not tell sleeping from resting.

WEBSITE FINDING (Sleep Foundation, Hill’s Pet) — UNOFFICIAL FINDING: puppies 16–20 hours, seniors 18–20 hours. No scientific or veterinary source we opened confirms those figures; for puppies at 16 weeks the large study in the table found about 11 hours.

The number of hours does not decide. VCA Animal Hospitals advises asking, instead of counting hours:

• Are these my dog’s typical sleep times?
• Does he still jump up for his usual stimuli?
• Is he missing out on his usual activities because of sleep?
• Does he seem alert and rested when awake?
• Does he have any other symptoms?

The 2026 review adds that daytime sleepiness is hard for owners to identify, because sleeping during the day is normal in dogs.

Our opinion: a healthy dog does not sleep nonstop all day. He wakes from time to time, makes a round of the house, and goes back to sleep. A dog who lies around all day and does not wake for what usually wakes him is not right. If you are not sure, ask your vet.

2 What studies say about sleep and behavior

This is why the topic is in the behavior section instead of the health one. First, what is proven: the studies we found show a link between sleep and behavior, not a cause.

• Owner survey (Tooley and Heath, 2022; 1,330 dogs, UK): problem behaviors were mildest in dogs that slept 8–10 hours while the owner was in bed. Both less than 8 and more than 10 hours went with worse behavior. The authors say the optimal amount of sleep is hard to define, and that a dog who sleeps badly may be a healthy dog who is justifiably disturbed at night.
• Laboratory dogs (Schork et al., 2022; 13 dogs in kennels): in dogs whose sleep was more broken, there was more inactivity by day, less play and alert behavior, and more eating. The authors say they cannot separate cause and effect.

WEBSITE FINDING (talktothepaw.io, Noble Vet Clinic) — UNOFFICIAL FINDING: a dog who has not slept enough yawns at odd times, is irritable, clumsy, slower to react and finds it harder to focus, and his threshold for growling or snapping drops because he controls his impulses less well. No study we found measures this in dogs, or measures the aggression threshold against sleep.

Our opinion: before you call something a behavior problem, look at how he sleeps: how often he wakes, whether something interrupts him, and whether he is rested when awake.

3 What steals a dog’s sleep in an ordinary house

Our opinion: what most often steals sleep. No study we found measures this.

• No quiet place. A busy household with nowhere to withdraw to is the most common thief of all. The safe space is also the sleep space; they are the same room, the same bed, the same rule.
• Constant low-level stimulation. Street noise, people passing a window, the gate, a television. Nothing big enough to be an event, all of it enough to keep him half awake — and a dog who answers the gate has a job that never ends (barking).
• Being woken. For affection, for a photograph, because he looks sweet. It is the easiest one to fix and the least often noticed.
• Over-scheduling. A dog whose day is a chain of events never fully comes down. Downtime is not wasted time.
• Pain — and for a flat-faced dog, disturbed breathing, which is the next section.

4 Why this is an airway question for a Frenchie

Brachycephalic obstructive airway syndrome is not only a daytime problem. A review (Mitze et al., 2022) says abnormal sleep is common in flat-faced dogs and linked to disordered breathing during sleep: sleeping with an open mouth in sitting or elevated positions, broken sleep, sleep apnea, waking, or complete inability to sleep. The same review says sleep disorders, together with reflux and high blood pressure, further affect a dog’s welfare, that the consequences are progressive, and that the breathing problem in sleep gets worse in REM (rapid eye movement) sleep, particularly in older, obese dogs.

A more recent review (Niinikoski and Rajamäki, 2026) says risk factors for sleep-disordered breathing are a short, flattened skull, moderate or severe BOAS (the breathing disorder of flat-faced breeds) and excess weight. The signs owners notice most often are snoring, restless sleep, sleeping sitting up or with a toy in the mouth, and pauses in breathing. Snoring does not match the degree of disorder: it occurs even without breathing pauses and does not track their number in flat-faced dogs, so it cannot be the only indicator. That is why a dog can have disordered breathing even when he sleeps quietly.

Only the first part of this chain is proven (the review above); the rest is an assumption:

narrow airway → broken sleep → lower threshold → “he has been grumpy lately”

In studies the link between sleep and behavior is only a correlation, and we did not find a study measuring behavior outcomes specifically as a result of BOAS-related sleep disruption. So the chain is our assumption, not a finding.

What follows is practical and diagnoses nothing. If your flat-faced dog snores heavily, wakes repeatedly, sleeps propped up or with his head raised, or seems permanently tired, that is a conversation with your vet rather than a personality trait. Start at BOAS.

5 The question to ask your vet

Two things get run together constantly, including by owners who are trying to be careful.

Only a vet can tell what the noise means. In the four-point functional grading used by one study (Liu et al., 2017; 604 dogs, 214 of them French Bulldogs), the grade is set by a clinical exam before and after an exercise tolerance test:

Among the 214 French Bulldogs in that study, 43.5% were grade II and 15.4% grade III. The sample was not random, so this does not say what share of all Frenchies have BOAS.

Our opinion: do not ask your vet “is he okay?”; ask “what grade is he?”. The first question gets you an impression, the second a measurement. And “my vet says he is fine” does not mean “there is nothing to manage”: a vet answers whether something needs treating, while whether you turn around on a warm day is your question, because the vet is not on the walk. We do not know whether your vet uses this exact system, so ask which one they use.

6 Spike: our experience

Our stories and opinions on this page are our personal experience with one dog, Spike. One dog is not the measure for every dog — for your dog, your vet decides.

Spike’s reality  ·  Dominican Republic

“The vet grades the airway. We read the fuel gauge.”

Spike sleeps quietly. Not silently and not unconditionally — it depends on the position — but you can barely hear him most nights, he does not wake often, and he does not sleep propped up. When we hear him snore, we know something is wrong, for example that something is blocked.

When we leave him alone, Spike sleeps, wakes after a while, makes a round and goes back to sleep.

Two things we are not going to claim. We do not have a grade for him, in either direction: no formal functional grading is on record. What is on record is that across years of repeated visits with the same vet, BOAS has never once come up as a problem, and the summary has been “he is good”. A condition that never arises across years of monitoring is not a measurement. And not having had surgery is neither a virtue nor a plan: that depends entirely on grade, and a dog at the severe end is harmed by waiting.

Two instruments came out of living with him, and they cost nothing.

1. Three levels, on the walk. The classic Frenchie grunting turns out to be a fuel gauge:

Three notes go with that, and copying it without them can be dangerous. The levels are individual: one dog’s level 2 is another dog’s level 3, so the instruction is to learn your dog’s three sounds, which takes a few ordinary walks. Heat moves the whole scale: level 2 at 22 °C (72 °F) is not level 2 on a cool morning — same sound, far less margin behind it, so on a warm day that reading means stop, not watch. Above 24 °C (75 °F) there is no walk at all — that is our absolute limit (see heatstroke). And stopping at 3 works because we know this dog: if you do not know yours yet, turn around at 2.

2. The sound of sleep, as a baseline. This one is structurally better, because it measures change rather than level. His baseline is quiet, established over years rather than assumed. Breathing can be disordered even in silence: snoring does not track how disordered the breathing is (Niinikoski and Rajamäki, 2026), which is why we watch for change, not for silence. If we hear something that is not the baseline, we immediately check whether it is the position or something else.

Position matters: the review (Mitze et al., 2022) lists sleeping in a sitting or elevated position among the signs of disordered breathing in sleep. Why a dog chooses such a position is not proven; our opinion is that he is compensating for a narrowed airway.

Where the line stays: a new noise at night, or a dog who starts sleeping propped up, is a vet conversation, not a home conclusion. We notice and report; the vet grades. And the good news carries a date on it: the review (Mitze et al., 2022) says the consequences are progressive and that the breathing problem in sleep gets worse particularly in older, obese dogs. What is fine now can get worse with age and excess weight.

Our opinion: Spike is not a classic Frenchie. His muzzle is not extremely flattened, so we think that is why he sleeps quietly. That is an observation, not a measurement: we have no measured muzzle ratio and no BOAS grade.

About the Author

Spike’s Dad

Not a veterinarian — the human behind Spike, a dark brindle Frenchie, for 7+ years. What is written here is checked as carefully as we can against the sources listed above. When real life with Spike differs from the studies, we say so.

How this site is researched →