Do dogs dream? What sleep science says about those twitching paws

No dog has ever woken up and described a dream, so the evidence is indirect. It is also pretty strong. As psychologist Stanley Coren has explained, a dog’s brain is built along the same basic lines as ours, and when dogs sleep their brain waves move through the same stages of electrical activity that a sleeping human’s do.

One of those stages is REM sleep, named for the rapid eye movements you can sometimes see flickering under a sleeping dog’s lids. In humans, people woken during REM almost always report that they were dreaming. Dogs show the same outward signs during that stage: breathing turns shallow and irregular, muscles twitch, paws paddle and eyes dart behind closed lids.

The most striking evidence that animals dream about their actual lives comes from rats. In 2001, MIT neuroscientists Kenway Louie and Matthew Wilson recorded cells in the hippocampus, a brain area tied to memory, while rats ran laps on a track for food. Each run produced a distinctive pattern of firing, almost like a fingerprint of the route.

Then they recorded the same rats asleep. In about half of the more than 40 REM episodes they examined, the same pattern came back, replayed at roughly the speed of the original run. The match was so close the researchers could tell where on the track the rat would have been, and whether it was running or standing still. “We know that they are in fact dreaming and their dreams are connected to actual experiences,” Wilson told MIT News.

The study was published in the journal Neuron. It didn’t include dogs, and nobody has done the same kind of recording in a pet dog. The jump to dogs is an inference: if a rat’s brain rehearses its day during REM, a dog’s larger and more complex brain very likely does something similar.

This is where the science runs out and educated guessing begins. Coren describes older lab work in which scientists disabled the part of the brainstem (the pons) that normally keeps the body still during dreams. Those dogs moved in their sleep, but only during the dream stage, and appeared to act out dog activities: a pointer, for instance, seemed to search for game. Coren and others suggest dreams follow breed and habit, so a springer spaniel might flush an imaginary bird.

Harvard psychologist Deirdre Barrett has made the more heartwarming point. Because dogs are so attached to their people, she told People magazine, it is likely they dream about their owners: your face, your smell, pleasing you or annoying you. That is a reasoned guess from human dream research, not a measurement, but it is a reasonable one.

Sleep also seems to do real work for dogs. In a 2017 study in Scientific Reports, researchers at Eötvös Loránd University taught 15 pet dogs new commands, then recorded their brain activity during a nap. Dogs that showed more bursts of a particular brain rhythm, similar to human “sleep spindles”, learned more. That study looked at non-REM sleep and says nothing about dreams directly, but it fits the bigger picture: a sleeping dog’s brain is busy sorting through its day.

Possibly. Coren has said, as reported by the American Kennel Club, that small dogs such as Chihuahuas dream more often in a night, starting a new dream roughly every ten minutes, while big dogs dream less often but for longer. Treat that as an expert’s rule of thumb rather than a measured result: we couldn’t find a published study that tested it in dogs.

If you want to catch a dream in progress, Coren suggests watching a medium-size dog about 20 minutes after it falls asleep (the AKC gives a 10 to 20 minute window). Look for irregular breathing, twitching and eyes moving under the lids. The AKC also notes, citing Vetstreet, that puppies and senior dogs dream more than middle-aged dogs.

Most of the time, let it sleep. Whimpering and paddling during REM are normal, and a dog startled awake can be disoriented enough to snap without meaning to. If you feel you must, say its name softly from a little distance rather than touching it.

A good day tends to make for good sleep. Plenty of exercise, a predictable routine and a comfortable, safe bed are the best gifts you can give a dreaming dog. If your dog comes home from a kennel stay and sleeps for a day straight, that is common too: see why dogs are tired after boarding.