Bed-sharing with dogs not tied to worse sleep

Clinical takeaway: Patients who ask about a dog in the bedroom can be told that, unless it is causing them problems, sleeping with one appears not to cost measurable sleep. 

Advice for patients who sleep with a dog has rested on mixed evidence. Several earlier studies linked sleeping alongside a dog to disturbed nights, others found no effect, and some found that self-reported sleep ran better than sensor readings indicated. Far less is documented about the effect on the dogs. An observational study now examines both directions at once. 

Sleeping with a dog on the bed did not track with total sleep time or sleep efficiency across 777 nights, and neither did a human co-sleeper or where the dog slept. Dog nighttime activity showed no tie to sleeping location, other dogs in the home, or feeding frequency across 1,093 nights. 

Nights with more dog activity coincided with more human activity, though the effect was small. About six in 10 pairs showed a close link between human and dog movement within five minutes and about four in 10 showed none. Among pairs with a link, human movement came first in nearly half, both moved within the same minute in about a third, and the dog moved first in fewer than one in five. 

Nearly half of owners said their dog interrupted their sleep, yet sensor-measured sleep held steady across every dog-related variable. Owners with more than one dog rated their sleep worse than owners with one, though that model fit no better than one with no predictors. Where the dog slept did not move self-rated sleep quality. 

The observational study followed 25 adults who lived in or near Ontario and their 38 huskies and malamutes for about four weeks, pairing wrist and collar sensors with an end-of-study sleep questionnaire. 

The investigators plan to compare companion dogs with working dogs, free-roaming dogs, and wolves. They also call for sensors that record every five to 10 seconds, which would show who moves first in the pairs that stirred within the same minute. 

"Our findings suggest that nighttime activity in humans and dogs is closely coupled and there may be discrepancies between objective and subjective sleep measures," said Lavania Nagendran of the Department of Anthropology at the University of Toronto Mississauga. 

Source: Li MF, et al. (2026 Oct 7) PLoS One. Who is disrupting whom? Examining the nighttime activity patterns of humans and their dogs