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It can be unsettling when an older dog seems to spend most of the day asleep. Sometimes it is completely normal. Other times, “sleeping all day” is really a sign of low energy, discomfort, or illness.
A helpful way to think about it is this: sleep itself is not the enemy. A change in sleep, paired with changes in appetite, mood, mobility, breathing, thirst, urination, or awareness, is what deserves attention.
Important note: This article is general education, not a diagnosis. Always check with your dog’s veterinarian, especially if the sleepiness is new, worsening, or paired with other symptoms.
How much sleep is normal for a senior dog?
Many dogs sleep far more than humans, and sleep needs often increase with age. The American Kennel Club notes that most geriatric dogs may sleep around 12 to 15 hours per day, and that changes in sleep habits can sometimes point to a medical issue. PetMD also describes typical adult sleep totaling up to around 16 hours a day, with variation by age, breed, and lifestyle.
That said, owners often report numbers higher than that for seniors, especially in large breeds or dogs with lower activity. Here is the key distinction:
- A dog who sleeps a lot but wakes easily, seems interested in food, enjoys short walks, and looks comfortable may simply be aging normally.
- A dog who sleeps a lot and, when awake, seems withdrawn, sore, confused, or “not themselves” may be telling you something is wrong.
A quick “sleep vs. lethargy” check
Try this gentle test once or twice (not repeatedly all day):
- Do they wake up when you quietly say their name or open the treat jar?
- When they stand, do they move normally, or do they look stiff, slow, or pained?
- Do they engage for a minute or two, or do they seem “flat” and quickly lie back down?
If your dog is difficult to rouse, weak, or mentally “not there,” treat it as urgent and call a veterinarian.
Common, non-scary reasons senior dogs sleep more
Aging changes the body in ways that can legitimately increase rest:
- Lower stamina and slower recovery after activity.
- More frequent naps instead of one long, deep sleep.
- Less novelty seeking (older dogs may be content with shorter bursts of engagement).
Environment matters too. Cold rooms, fewer outings, less play, and predictable routines can all lead to more daytime sleeping. Pet sleep research is also limited by the fact that much of what we know comes from controlled settings or owner reports, and “normal” can vary widely between individuals.
When sleeping all day might be a clue something is wrong
Below are common medical and behavioral causes that veterinarians often consider when an older dog becomes noticeably sleepier. Many of these conditions overlap, which is why it is so important not to self-diagnose.
Pain, especially arthritis or other chronic aches
Chronic pain is one of the most overlooked reasons older dogs “sleep all day.” Pain does not always look like crying or limping. It often shows up as:
- reluctance to go up/down stairs
- slower to stand up
- less interest in walks or play
- irritability when touched
- choosing rest over interaction
Osteoarthritis is a degenerative joint condition that can interfere with daily life and comfort. The AAHA pain management guidelines emphasize actively recognizing and addressing chronic pain, including using owner observations as part of assessment.
What you can do now: Keep notes on mobility changes (see the tracking section below) and ask your vet about pain screening. Do not start human pain medications. Many are dangerous for dogs.
Canine cognitive dysfunction (dog dementia) and sleep-wake changes
Canine cognitive dysfunction syndrome is an age-related brain condition that can look like “old age” at first. Cornell’s canine health resources describe it as common and potentially underdiagnosed, in part because changes happen gradually and can be mistaken for normal aging.
One hallmark is a shift in sleep patterns: more daytime sleeping, restlessness at night, pacing, or nighttime vocalizing.
What you can do now: If you notice confusion, getting stuck in corners, new anxiety, house soiling, or altered sleep cycles, bring it up directly with your vet. Treatment is individualized and may combine routines, environmental changes, and medication or supplements depending on the case.
Endocrine issues like hypothyroidism or Cushing’s disease
Hormone disorders can quietly drain energy.
- Hypothyroidism in dogs can cause lethargy, weight gain, obesity, and coat/skin changes. Diagnosis involves clinical signs and blood testing, and treatment is typically lifelong thyroid hormone replacement.
- Cushing’s disease (hyperadrenocorticism) is more common in middle-aged and senior dogs and often includes increased thirst, panting, and skin/coat changes.
What you can do now: Note any weight change, thirst changes, panting, hair thinning, or recurrent skin/ear issues. These details help your vet choose the right tests.
Kidney disease, liver disease, or other “slow burn” illnesses
Chronic diseases often start subtly. For chronic kidney disease, PetMD notes early signs can include increased drinking/urination, lethargy, picky appetite, and weight loss, and that basic diagnosis commonly includes blood work and urinalysis.
What you can do now: Pay attention to water intake, urine volume, appetite shifts, nausea signs (lip licking, drooling), and weight.
Heart disease or reduced oxygen delivery
Some dogs sleep more because activity becomes harder. Reduced endurance, fatigue, coughing, and breathing changes are especially important to mention to a veterinarian. Educational resources on congestive heart failure commonly emphasize decreased endurance and lethargy as possible signs alongside respiratory symptoms.
What you can do now: If you notice coughing, faster breathing at rest, fainting, or your dog seems unwilling to lie on one side, call your vet promptly. Breathing issues are not a “wait and see” situation.
Anemia (low red blood cells) or other blood-related issues
Anemia can cause lethargy and weakness, and may also cause pale gums or faster breathing/heart rate.
What you can do now: If your dog’s gums look pale/white, or your dog is weak, this can be urgent. Contact a veterinarian right away.
Medication side effects
Many commonly prescribed senior-dog meds can cause drowsiness, including some anxiety medications, anti-nausea drugs, certain pain medications, and drugs for itching or allergies.
What you can do now: Make a list of everything your dog gets (prescriptions, supplements, preventatives). Bring it to your vet and ask whether sleepiness could be a side effect or interaction.
Depression, stress, and reduced enrichment
Older dogs can sleep more when the world shrinks: fewer walks, less social time, less sniffing, less novelty. They can also respond to household changes (moving, loss of a companion, new baby, schedule shifts) with withdrawal.
What you can do now: Add gentle structure: brief sniff walks, short training games, food puzzles, and predictable social time, adjusted for your dog’s comfort.
Red flags that mean “call the vet”
If you see any of these, do not chalk it up to age:
- sudden or rapidly worsening sleepiness
- trouble waking up or unusual disorientation
- refusing food for more than a day, or drinking far more than usual
- vomiting, diarrhea, black stools, or repeated gagging
- coughing, labored breathing, or breathing faster at rest
- collapse, weakness, stumbling, or seizures
- pale gums, yellow tint to eyes/skin, or a swollen belly
- obvious pain, yelping, or sudden reluctance to move
When in doubt, call. A quick phone triage can tell you whether to come in urgently.
What to do at home before the appointment
You do not need perfect data, just useful patterns.
Track a few basics for 3 to 7 days
Use your phone notes:
- sleep pattern: “up and alert” windows vs. sleeping
- appetite: normal, picky, or refusing
- water intake: normal vs. noticeably increased
- bathroom habits: accidents, straining, changes in frequency
- mobility: stiffness, trouble with stairs, slipping
- mood: clingy, withdrawn, irritable, confused
- breathing: any cough or heavier breathing at rest
These notes can speed up diagnosis because many senior conditions look similar at home.
Do a comfort audit
Small upgrades can make an older dog more willing to be awake and engaged:
- non-slip rugs or runners on slick floors
- a supportive bed (especially if arthritis is suspected)
- easy access to favorite resting spots
- ramps or steps for couches and cars
- shorter, more frequent walks instead of one long outing
If pain is part of the picture, comfort changes at home help, but they do not replace medical pain control. AAHA pain guidance supports proactive pain management plans, often multimodal, tailored to the individual pet. (AAHA)
Keep activity gentle but consistent
For many seniors, the sweet spot is frequent low-intensity movement:
- 2 to 4 short sniff walks
- slow treat scatter in the yard or on a snuffle mat
- 2 minutes of easy cues (touch, sit, find it)
- light play that stops before heavy panting
If your dog is sore afterward or sleeps harder the next day, scale back and discuss pain with your vet.
What your veterinarian may recommend
Your vet will start with history and a physical exam, then decide which diagnostics make sense. For senior pets, AAHA encourages more frequent wellness exams and notes that regular visits can help catch issues early, even in “healthy-looking” seniors.
Depending on symptoms, your vet may suggest:
- blood work and urinalysis (common starting point for systemic illness)
- thyroid testing (if hypothyroidism is suspected)
- screening for kidney disease
- pain and mobility assessment (especially for arthritis)
- cognitive dysfunction evaluation if behavior and sleep-wake cycles have changed
Be ready to share your notes and a medication list. That alone can save time.
Where research is limited
- “Normal” sleep in senior dogs has a wide range. Dogs vary by breed, size, lifestyle, and health, and many sleep studies are done in controlled conditions rather than real households, which limits how confidently we can define a single “healthy” number for every dog.
- Cognitive dysfunction is likely underrecognized. Slow changes can be misread as normal aging, which can delay evaluation and treatment.
- Owner observations are essential but imperfect. Most of us are estimating sleep, not measuring it with medical-grade tools. Trends matter more than exact hours.
The bottom line
A senior dog sleeping “all day” can be normal, but a new pattern deserves curiosity, not dismissal. Your goal is not to keep your dog awake, it is to make sure they are comfortable, mentally present, and still enjoying their days in the ways that matter to them.
And no matter what you read online, check with your dog’s veterinarian. They can help you separate normal aging from treatable problems, and they can do it safely.
Sources
- American Kennel Club (AKC), “Too Much Sleep: Is There Such a Thing for Senior Dogs?” (American Kennel Club)
- PetMD, “Why Do Dogs Sleep So Much?” (PetMD)
- AAHA, “Supporting Your Senior Pet: Veterinary Care Recommendations” (AAHA)
- AAHA, “2023 AAHA Senior Care Guidelines for Dogs and Cats” (PDF) (AAHA)
- AAHA, “2022 AAHA Pain Management Guidelines for Dogs and Cats” (PDF) (AAHA)
- Cornell University College of Veterinary Medicine, “Cognitive Dysfunction Syndrome” (vet.cornell.edu)
- Merck Veterinary Manual, “Hypothyroidism in Animals” (Merck Veterinary Manual)
- VCA Animal Hospitals, “Hypothyroidism in Dogs” (Vca)
- VCA Animal Hospitals, “Arthritis in Dogs” (Vca)
- PetMD, “Cushing’s Disease in Dogs: Symptoms, Diagnosis, and Treatment” (PetMD)
- PetMD, “Chronic Kidney Disease (CKD) in Dogs” (PetMD)
- PetMD, “Anemia in Dogs” (PetMD)
- The Guardian, “My pet sleeps all day and all night. Is that normal?” (discussion of variability and study limitations) (The Guardian)