Dog owners may be assigning blame in the wrong direction when sleep turns restless. In a four-week study of 25 people and 38 dogs, human movement preceded dog movement more often than the reverse among pairs whose nighttime activity was correlated.
The study, published Oct. 7 in PLOS One, also found no significant association between sharing a bed with a dog and changes in owners’ objectively measured sleep duration or efficiency. That does not prove dogs never disturb sleep, but it challenges the assumption that they are consistently responsible.
Ming Fei Li of the University of Toronto, Lavania Nagendran of the University of Toronto Mississauga and their colleagues monitored participants for about four weeks. People wore activity monitors on their wrists, while dogs wore comparable devices on their collars.
The monitors recorded movement in one-minute intervals. Researchers then compared activity during each person’s nighttime sleep period, looking for occasions when movement by one member of a human-dog pair was followed by movement from the other within five minutes.
Humans moved first more often
The researchers analyzed 36 human-dog pairs after excluding two pairs with incomplete activity data. They found correlated activity in 22 of those pairs, or about 61%.
Within that group, human activity came before dog activity in about 45% of the pairs. Dog activity came first in about 18%, while activity occurred within the same one-minute interval in about 36%.
Those figures require careful interpretation. Movement occurring first does not establish that one sleeping partner awakened the other, and simultaneous movement does not identify a cause. The researchers did not directly observe the participants or collect sound information that could have distinguished turning over, leaving the bed, barking, snoring or other nighttime events.
The study’s broader sleep findings were similarly measured. Across 777 nights included in the human sleep analysis, bed-sharing with a dog was not significantly associated with total sleep time or sleep efficiency. Dog sleeping location also did not significantly affect perceived sleep quality, including among participants who felt their dogs interrupted them.
One result did differ between objective measurements and personal perceptions. Participants with more than one dog reported poorer subjective sleep than people with one dog, although the number of dogs was not associated with worse objectively measured sleep. The researchers cautioned that the statistical model for subjective sleep was not significantly better than a model without those predictors.
What the monitors could not establish
Activity monitors make extended home observation possible, but movement is not the same as confirmed wakefulness. The American Academy of Sleep Medicine explains that actigraphy estimates sleep and wake patterns through motion data and can incorrectly classify quiet wakefulness as sleep.
The canine measurement had an additional limitation. The device used in this research had not been validated for determining dogs’ physiological sleep and wake states. Researchers therefore described the canine data as activity and inactivity rather than confirmed sleep and wakefulness. Small head or paw movements, including movement during dreaming, could be counted as activity.
The participant group also limits how broadly the findings can be applied. All 38 dogs were huskies or malamutes between 2 and 12 years old, selected as part of a larger research project. The researchers said activity patterns may vary among breeds and called for future work involving more dogs of different breeds and ages.
There was no comparison group of people who did not own dogs. Eleven participants who never shared a bed with their dogs served as the bed-sharing comparison group, but the research could not determine whether dog owners sleep differently from people without dogs.
The sample was small, and data collection took place during COVID-19 lockdown measures, when household and work routines may have differed from other periods. Previous research on pet co-sleeping has also produced mixed results, making this study one measured addition rather than a final answer.
For owners, the findings do not establish that every dog belongs in bed or that an individual dog cannot disturb sleep. They suggest that nighttime disruption can be reciprocal and that, in this monitored group, dogs did not account for significant reductions in human sleep duration or efficiency. Some dogs may not deserve all the blame for a restless night.
What would you do if your dog were in this situation? Share your thoughts in the comments.
By Sarah Mitchell — 8 years as a local-news reporter covering animal welfare, shelters, neighborhood disputes, and public-safety pet stories.
