The American Veterinary Medical Association estimates that dogs can be found in roughly one-third of homes in the United States.
Surveys of hospital patients in both 2002 and 2015 found more than 50 percent reported having a pet at home.
More than half of them said they allow pets in their bedrooms at night when they sleep.
More than 40 percent said they believe their pets help them to sleep better. Only half as many thought the pets were a disruption.
Those statistics are included in a study by Mayo Clinic researchers designed to evaluate whether human sleep is affected when dogs are allowed in the bedroom at night.
The study tracked the sleep patterns of 40 healthy adults and their dogs. None had sleep disorders, and 80 percent of them were white women.
All the subjects allowed their pets in the bedroom at night, but only some let the dogs sleep in the bed with them.
None kept more than one pet in the bedroom with them.
Both dogs and humans were tracked for a total of seven nights over the course of the five-month study.
To monitor their movements, both the dogs and humans were outfitted with accelerometers. The ones worn by humans were capable of detecting both motion and light.
The researchers concluded that for healthy, middle-aged women, having one adult dog in the bedroom might not be overly disruptive to their sleep.
However, sleep efficiency may suffer somewhat if the dog shares the bed.
What is sleep efficiency?
Healthline spoke with Dr. Jeffrey Durmer, co-founder and chief medical officer at FusionHealth in Georgia, about the study and the subject of sleep itself.
When it comes to sleep efficiency, Durmer said, “We look at how much time, when you actually get in bed, do you spend sleeping in bed versus awake in bed. So the efficiency number is a simple ratio of the amount of time asleep divided by the total amount of time in bed.”
In the study, sleep efficiency was based on dog size, whether the dog was in the room or in the bed, and whether there were one or two humans in the bed.
And the study says...
Within the study group, human sleep efficiency was highest when the human slept with a human partner and had a medium-sized dog (21 to 50 pounds) in the room but not in the bed.
Conversely, human sleep efficiency was lowest when there was no human partner and there was a small dog in the bed.
For dogs, time at rest is what’s measured.
Of the dogs studied, rest time was highest for large dogs (more than 50 pounds) that slept in the bed with only one human.
Overall average sleep efficiency rating for humans was 81 percent.
Average rest time for dogs was almost 85 percent.
In response to the human sleep efficiency outcome, Durmer stated, “Although 80-something percent is considered normal, what we really look for is sleep efficiencies that are even higher. We hope to see them in the 90s in people who are really good sleepers.
“So although this [rating] is acceptable sleep efficiency, I wouldn’t call it optimal. That’s for sure,” he added.
What is it about people and dogs?
“Dogs are complementary and symbiotic to humans,” said Dr. Rafael Pelayo, clinical professor, psychiatry and behavioral sciences, at Stanford Center for Sleep Sciences and Medicine in California.
However, sleeping isn’t necessarily as pleasant for animals as it is for people.
“There’s nothing inherently more dangerous that an animal can do than sleep. Sleeping animals can be attacked,” he noted.
“Humans only sleep about 90 minutes at a time,” Pelayo told Healthline. “There’s a misconception that humans sleep eight hours in a row. [If that were true] we would have been picked off by the lions and tigers.
“Our strength,” said Pelayo, “is the fact that we’re social animals and we can organize.
“Humans against lion, the lion always wins,” continued Pelayo. “But a tribe of humans can take on any lion.
“We have excellent color vision,” Pelayo said. “[But] we have lousy night vision.”
That gives us an advantage over animals during the day, but puts us at a disadvantage at night.
“So if we have a vulnerability at night, how did we become the top predator on the planet?” asks Pelayo. “I really think that dogs played a role in this because dogs, actually, are up and down, awake during the night, and they see very well in the dark.”
Pelayo said that certain anthropologists have told him that dogs were the first animals domesticated by humans.
“So it might not surprise you when some people feel better when they have a dog around because the dog watches over you,” said Pelayo.
“I can understand why somebody who feels comfortable with a dog would like the dog to be there at night,” said Pelayo. “It gives them that measure of safety.”
What about children?
Although not addressed by this study, parents sometimes allow children to sleep with their pets, too.
“In children, I’ve seen kids who are kind of scared of the dark and nervous, maybe they go to the bathroom a lot. Sometimes the parents let the dog sleep in the kid’s room and the kid feels safer,” Pelayo said.
However, with regard to children, Pelayo said, “Dogs don’t sleep like humans do. Dogs sleep on and off throughout the day. The dog’s not going to sleep eight hours in a row with a child in the same bed. The dog is going to get out of bed and get back in later. And that can be disruptive.
“It’s one thing if the kid says, ‘I don’t mind the dog being in bed with me,’” said Pelayo. “It’s different if the kid says, ‘I can’t sleep unless the dog is with me.’
“There’s a distinction there,” continued Pelayo. “One is that you’re welcoming the dog into the bed because you enjoy their company. The other is that you’re dependent on that dog. That should not happen. You should be able to sleep well whether the dog is there or not, or in the bed with you.”
Take this study with a grain of salt
Durmer suggested that while accelerometers can detect movement, they aren’t able to detect whether or not the person is actually asleep.
“Quality of sleep is really hard to discern from sleep efficiency alone,” said Durmer. “Accelerometers [which only measure movement] can’t tell you about sleep.”
The study authors were careful to point out that their conclusions shouldn’t be applied to the population at large.
Said Durmer, “One of the problems with the study then, is that ‘Is it applicable to everybody that sleeps with an animal?’ And I have to say then, that no, it isn’t. It’s a small study. There is no control group for this study, so there’s nothing to compare it against.
“I would argue that given that this is mainly women sleeping with a dog, in the room or in the bed, that is only applicable to women who sleep with a dog, in or out of the bed, if they’re also at a normal BMI and don’t have sleep disorders,” said Durmer.
Society and sleep issues
As a society, we have a sleep problem.
A large percentage of our population suffers from sleep issues that later translate into even larger health problems, along with their associated costs.
“I think the reality is that we don’t talk about sleep enough and value it enough,” said Durmer.
Studies like this one, he added, “give us the opportunity to talk about it and why, and then also kind of refocus the discussion on this, which is that 45 percent of people, on a night-to-night basis, just don’t sleep well.
“In fact, we kind of sweep [the problem] under the rug and ignore it for years before it becomes a medical problem or causes hypertension or diabetes or some other downstream problem that should have been avoided,” said Durmer.
Three things you should know about sleep
Durmer points out that, “Your sleep quality is different than your sleep quantity.”
He lists the three most important factors that determine what scientists call sleep charge, or recharge.
- Sleep quality — basically, how well you sleep.
- Sleep quantity — how much sleep you get. Oftentimes, people with snoring or sleep apnea, for example, have problems with the amount of sleep they get.
- Timing — what time of day or night you sleep.
Timing issues are often a problem for people who work on overnight or late evening shifts.
“These are the three most important factors to determine how effective your sleep is,” said Durmer. Attention should be given to each.
The bottom line
As for sleeping with your dog, Pelayo sums it up simply.
“If you wake up feeling refreshed in the morning,” he said, “then whatever you’re doing with the dog or pet is OK. But if you wake up tired, something is wrong.”
“You should never ever wake up tired,” said Pelayo. “You don’t leave restaurants feeling hungry. You should not wake up feeling tired. So if you find yourself waking up feeling tired, then maybe we need to take a look at the pet.”