Why Does My Dog Sleep So Much?

The Short Answer

Dogs sleep between 12 and 14 hours a day on average — and some breeds and life stages push that to 18 hours. It’s completely normal. Dogs are polyphasic sleepers (many short sleep cycles vs. our single long one), they don’t have 9-to-5 schedules driving their wakefulness, and their sleep needs are genuinely higher than humans’. Puppies and senior dogs sleep even more. When to worry: sudden, dramatic increases in sleep combined with other symptoms.

You Work 8 Hours. Your Dog Sleeps Twice That. Here’s Why That’s Fine.

You leave for work. Your dog watches you go, sighs, circles twice, and goes back to sleep. You come home eight hours later. It’s been asleep for most of them.

The first instinct is to feel guilty (are they bored? depressed?). The second is to wonder if something’s wrong. The third, once you understand dog sleep biology, is just mild envy.

How Much Do Dogs Actually Sleep?

According to Stanley Coren, professor of psychology at the University of British Columbia and author of Do Dogs Dream? Nearly Everything Your Dog Wants You to Know (2012):

• Adult dogs: 12–14 hours per day, on average
• Puppies: 15–20 hours per day (growth hormone is released during sleep; puppies are essentially under construction)
• Senior dogs: 16–18 hours per day (lower energy, more restorative sleep needed)
• Large and giant breeds: Often sleep more than small breeds
• Working breeds on active days: May sleep more after intense activity

These numbers aren’t laziness. They’re physiology.

Why Do Dogs Need So Much Sleep?

Their sleep architecture is fundamentally different from ours

Humans consolidate sleep into one long block at night. Dogs are polyphasic sleepers — they cycle through many shorter sleep periods distributed across the day. This is an evolutionary adaptation from a species that needed to be responsive to threats and opportunities at any time, not just after dawn.

The trade-off: shorter total wakefulness relative to body size. Dogs spend roughly 50% of their day asleep, 30% in a drowsy resting state, and only about 20% fully active — compared to humans, who typically spend 33% asleep and 67% active.

Sleep quality is lower per cycle

Research in Behavioural Brain Research has found that dogs enter REM (dream) sleep more frequently than humans but spend less total time in it per cycle. Each sleep episode is lighter and less efficient than a full human night’s sleep, which means more sleep episodes are needed to accumulate the same restorative benefit.

Dogs don’t have structured wakefulness

Humans have social schedules, jobs, meals, and obligations that force sustained wakefulness. Dogs have none of these. When there’s nothing interesting happening — which for a dog home alone is most of the day — there’s no compelling reason not to sleep.

Do Dogs Dream?

Yes. This is no longer speculation.

Coren, drawing on sleep laboratory research, explains that dogs show all the neurological markers of REM sleep: rapid eye movements, twitching, irregular breathing, and occasionally vocalisation. The brain structures responsible for dreaming — the pons, which regulates REM sleep and temporarily paralyses voluntary muscles — are present in dogs.

Coren estimates that dogs probably dream about their daily experiences: things they’ve chased, people they’ve seen, activities they’ve done. Puppies and older dogs appear to dream more frequently than middle-aged dogs, possibly because the memory consolidation process is more active at both ends of the lifespan.

The twitching, muffled barking, paddling legs you see during a dog’s deep sleep? That’s REM. They’re having an adventure in their heads. Leave them to it.

Does Breed Affect Sleep Needs?

Yes, significantly.

• Large and giant breeds (Great Danes, Mastiffs, Saint Bernards) are famous for sleeping 16–18 hours a day. Their bodies burn more energy simply maintaining their size, and rest requirements scale up accordingly.
• Working breeds (Border Collies, German Shepherds, Belgian Malinois) sleep less than average on active days and more on sedentary ones — they’re energy-matched to their activity level with remarkable precision.
• Brachycephalic breeds (Bulldogs, French Bulldogs, Pugs) often sleep more partly because their compromised airways mean sleep is less efficient — they wake more frequently and need more total time in bed to get adequate rest. This is also why snoring and sleep apnea are common in these breeds.

My Dog Sleeps More Than It Used To. Should I Be Worried?

This is the crucial question, and the answer depends on what else is changing.

Probably fine:
– Recently increased activity level (a long hike, a new exercise routine)
– Change of season, especially into colder months
– Getting older (senior life stage naturally means more sleep)
– New addition to the household (stress-related extra rest is common)

Worth a vet visit if the extra sleep is accompanied by:
– Loss of appetite
– Weight loss or gain
– Decreased interest in things it normally enjoys
– Difficulty getting up or moving
– Unusual lethargy when awake (not just sleeping more, but seeming sluggish during waking hours)
– Changes in urination or defecation

These combinations can indicate hypothyroidism, anemia, infection, diabetes, heart disease, or other conditions that are very treatable when caught early. The sleep itself isn’t the red flag — the combination of symptoms is.

Is My Dog Bored or Depressed?

Dogs can experience something analogous to depression — veterinary behaviourists recognise a set of symptoms including social withdrawal, decreased activity, changes in appetite, and significantly increased sleep following major stressors (loss of a companion, major lifestyle change, chronic understimulation).

The distinction between normal heavy sleeping and depression-adjacent states is in the waking hours. A well-adjusted dog that sleeps 14 hours a day will be engaged, curious, responsive, and enthusiastic when awake. A dog that’s depressed or chronically understimulated will seem flat even when it is awake — low interest in play, food, interaction.

If your dog’s waking hours seem as listless as its sleeping ones, that’s worth addressing through enrichment, exercise, socialisation — and if those don’t help, a vet conversation.

Should I Wake My Dog During Deep Sleep?

The classic advice is: let sleeping dogs lie — and there’s real science behind it.

Dogs startled from deep sleep can react defensively before they’re fully oriented — this is behind many “bite out of nowhere” incidents, particularly in older dogs or dogs with hearing loss who can’t hear an approach. Always let sleeping dogs wake naturally or alert them gently from a distance before physical contact.

Quick Answers to Everything Else

My dog sleeps 16+ hours a day. Too much?
Depends on breed and age. For a Great Dane or a senior dog, that’s within normal range. For a 2-year-old Border Collie, probably worth a vet check.

Why does my dog sleep with its eyes partially open?
This is the nictitating membrane (third eyelid) showing — it moves to protect the eye during lighter sleep phases. Looks alarming, is actually normal.

Why does my dog spin before lying down?
Ancestral behaviour — wild canines would trample grass or vegetation to create a comfortable nest and check for snakes or insects. The behaviour persisted long after its practical purpose disappeared.

Should my dog sleep in my bed?
Your call — the main considerations are sleep disruption (if the dog moves or snores) and hygiene. There is no evidence that it creates behavioural problems or undermines hierarchy, which was a widely repeated but poorly evidenced concern.

My dog sleeps 18 hours on rest days but only 10 after a big hike. Why?
Activity calibrates sleep. More activity = more physiological repair needed = more wakefulness during the active period and actually somewhat less sleep afterward (adrenaline and interest keep them up longer during and immediately after stimulating activity). The relationship is real but not linear — observe your dog’s own patterns.

The Bottom Line

Your dog sleeping half the day is not a problem. It’s not boredom, not laziness, and not depression — it’s a biological reality built into a polyphasic species with different sleep architecture than yours.

The time to worry is when the sleeping changes suddenly without explanation, and when the waking hours lose their spark. A dog that bounces up at the sound of a treat bag, even after 15 hours of sleep, is a healthy dog living its best well-rested life.

Related Posts

• Do Dogs Dream?
• Why Does My Dog Twitch in Its Sleep?
• Signs Your Dog Is Depressed
• How Much Exercise Does My Dog Actually Need?

Sources:
Coren, S. (2012). Do Dogs Dream? Nearly Everything Your Dog Wants You to Know. W. W. Norton.
Frank, M.G. et al. Sleep in laboratory and domestic dogs. Behavioural Brain Research.
AKC — How much do dogs sleep?
AVMA — Canine wellness and behaviour.