Dogs twitch in their sleep. You may have even be awakened by your dog whimpering and moving his legs, as if he were chasing something. This lasts for 10, maybe 15, seconds; your dog takes a deep sigh; and then he goes back to a sound, peaceful sleep. This is simply twitching, not a seizure.
But, still, you may wonder, “Why does my dog twitch in his sleep? Is this normal?”
The answer is, yes, it’s normal. Most mammals–including humans–dream, according to what was called a landmark study in 2001 at the Massachusetts Institute of Technology. The study used rats, but it was groundbreaking.
Further research shows that not all mammals dream. Only predators sleep deeply enough to dream. The mammals they prey on stay alive by not sleeping so deeply that they can’t sense movement or hear a twig break.
Mammalian sleep consists of three phases: wakefulness (when they first go to sleep and are easily aroused), the rapid-eye movement phase (the phase of deep sleep, when dogs and humans dream), and the non-rapid-eye movement phase.
The rapid-eye movement phase usually happens about 20 minutes after your dog falls asleep, and you can tell the dog has entered this phase by seeing his eyeballs move, his legs twitch or move, and taking shorter breaths. That’s because he’s dreaming.
And this is the phase in which legs twitch or lurch and in which they can have night terrors. These are most common in puppies and old dogs, because the pons – the part of the mammalian brain that controls large-muscle movement – is not yet fully developed in puppies or is decaying in old dogs, according to research by Dr. Stanley Coren, professor emeritus at the University of British Columbia. You can read more in his book, “Do Dogs Dream? Nearly Everything Your Dog Wants You to Know.”
Other research shows that large dogs, like German Shepherds or Great Danes, are a bit more likely to have vivid dreams or night terrors than small dogs, like Dachshunds or terriers, because they tend to have longer, more complete dreams.
If we accept that dogs do have dreams, that leaves us to wonder what do they dream about?
Dog behaviorists at the American Kennel Club say that dogs don’t have the imagination that humans do, so their dreams cannot include monsters or frightening events that haven’t really happened.
They say that a dog’s dreams are likely an interpretation of events that have previously happened. They’re that dog’s memory of losing his bone, of another dog taking his food away, or of a fun walk he took last month.
That means that night terrors are your dog having a bad memory. He’ll likely whimper, or even bark or howl. His eyes could twitch or roll. The large muscles of his shoulders and hindquarters may twitch, his legs could even move as if he’s running.
You’ve heard the expression, “Let sleeping dogs lie.” It comes from moments like these. When a dog is having a night terror, he’ll probably awaken startled and disoriented, which could cause him to lash out and unintentionally bite or scratch you.
So it’s best to leave him alone until his dream ends. Don’t worry – he’ll be OK.
