Why does my dog sleep so much?

It depends mostly on age. VCA says most dogs spend at least half of every 24 hours asleep, even as adults, and that one adult might sleep 10 hours a day while another sleeps 14 (VCA). AKC describes the day as about half asleep, 30% awake but relaxing and 20% active (AKC).

Dogs sleep in several stretches rather than one long night, so napping in the day after a full night is normal (VCA). About 10% of a dog’s sleep is REM sleep, against up to 25% in people, and AKC links the difference to dogs’ irregular sleep patterns (AKC).

Far more than adults. AKC says a growing puppy may need up to 18 to 20 hours of sleep a day (AKC). No source we read gives a lowest normal figure, so judge your puppy against its own routine rather than a target.

• Short bursts of puppy energy between long naps are typical (VCA).
• As a puppy matures, it should not be sleeping away the whole day (VCA).
• A puppy that is suddenly much sleepier, or loses interest in play and food, should see a vet (VCA).

Tracking growth helps you spot a puppy that is off colour. Our puppy weight calculator shows whether weight is on track, and the puppy vaccination schedule covers the health checks in the first year.

Yes. Most senior dogs need 12 to 15 hours a day and some sleep up to 18. AKC counts larger dogs as seniors from about 6 years and smaller dogs from about 7 (AKC). Use our dog age calculator if you are not sure where your dog sits.

Sleeping all day and awake at night

A senior dog that sleeps by day and is restless or pacing at night may have cognitive dysfunction. Merck lists changed sleep-wake cycles among its signs, and in one study 28% of dogs aged 11 to 12 showed signs consistent with it (Merck). Owners of affected dogs often report more daytime sleep and trouble sleeping (Mondino et al.).

• Interacting with your dog during the day can help re-establish the day-night cycle (Merck).
• Your vet will rule out pain and other physical causes first (Merck).

Often, yes. AKC notes that dogs doze off whenever they like, often out of boredom, and that dogs not bred for a particular job will lie around for much of the day (AKC). Merck's advice for many behaviour problems starts with the same fix: exercise and mental stimulation suited to the dog's age and breed (Merck).

• Add a sniffing walk or a short training game each day.
• Use food puzzles instead of a bowl for some meals.
• A bored dog perks up when something happens. An unwell dog often does not.

Yes. An underactive thyroid slows the body down. Merck lists mental dullness, lethargy, exercise intolerance and weight gain, and says it is most common in dogs aged 4 to 10, usually medium to large breeds (Merck). VCA puts the average age at 6 to 7 years (VCA).

• Weight gain without eating more
• Feeling the cold, seeking warm spots
• A dry, dull or thinning coat
• Less desire to exercise

A blood test confirms it, and it is treatable with daily hormone replacement, though not curable (VCA).

Sleep and lethargy look alike from across the room. The difference shows when your dog is awake. A sleepy dog wakes easily and joins in. A lethargic dog does not want to get up or take part in normal activities, and VCA says that, or sleeping more than normal, is a reason to book a vet appointment (VCA).

Sleeping a lot and not eating is a combination to take to your vet. Our guide to a dog that is not eating covers that side. We found no veterinary source that measures whether dogs sleep more in winter or in hot weather, so judge a seasonal change the same way: is your dog still itself when awake? AKC also lists canine depression among causes of excess sleep (AKC).

As a general rule, yes: AKC says bigger breeds spend more time dozing (AKC). None of the veterinary sources we read gives hours of sleep by size or breed, so we do not print a breed table. Flat-faced breeds are one exception worth knowing: they can have sleep apnoea, which leaves them tired in the day (VCA).

For growth by breed, see our breed growth charts.

There is no fixed number of hours or days for most dogs, so call your vet to be safe whenever the extra sleep is a change from your dog's normal. The one published figure applies to seniors: more than 20 hours a day could signal a medical condition (AKC).

• Same day or emergency: hard to wake, cannot get up, or any collapse (VCA).
• Appointment soon: sleeping more than normal, not acting like itself (VCA).
• Routine check: a slow change over weeks, especially with weight gain or stiffness.

The dog behaviour checker gives a quick read on other changes too.

Every figure and threshold on this page comes from the veterinary sources below, and each one is linked where it is used. Where no source gives a cut-off, we say call your vet rather than invent one.