Can Dogs Have Nightmares?

Studies have shown that dogs can dream, so they probably can have dog night terrors, too.


We dream when we sleep, and science shows that vertebrates can dream, which includes dogs. And if they can dream, then, logically, dogs can have dog night terrors, or nightmares, too. Puppies can be active in their sleep, too.

A study by the Massachusetts Institute of Technology found that all vertebrates can dream (Neuron, Jan. 25, 2001). The researchers ran a group of rats through a maze all day, tracking what parts of their brains were activated by this activity and by when they slept. The same parts of the brain were stimulated, causing the researchers to deduce that the rats were reliving their earlier activity. And, they determined that it meant the rats were dreaming.

Dog Whimpering in Sleep

If you hear your dog whimpering in his sleep, you can bet he’s dreaming. It’s part of his rapid eye movement, or REM, sleep cycle. Dogs also scream in their sleep, which is most likely due to a bad dream, just like us. That said, if a dog regularly screams during sleep, you may want to talk with a veterinarian to be sure it’s not a pain issue or other physical problem.

Basically, sleep – in humans and in dogs – comes in two main phases of sleep (both with subcategories):

  • REM or deep sleep
  • non-REM or lighter sleep

The REM phase is when both species have dreams – and nightmares. This phase usually begins 10 to 20 minutes after dogs fall asleep – you can often see their eyeballs moving underneath their eyelids during it.

Dog Dreams

The complexity of dogs’ brains, relative to humans’ brains, leads to this question: What do dogs dream about? Scientists believe that all animal dreams (and nightmares) are limited to their own, probably recent, experiences. That’s why dogs can seem to be chasing, barking at, or even eating something.

Researchers don’t believe that dogs can dream up monsters or assign fanciful personalities to real people or dogs. They believe that dogs can only relive something they’ve already done.

Therefore, a dog’s nightmare is likely based on something that he experienced, such as being beaten, starving, or being separated from his person.

Of course, we don’t know for sure that dogs can have nightmares because they can’t talk and tell us what they’re really dreaming about.

Let Sleeping Dogs Lie

The Sleep Foundation says that dogs often dream things that are indicative of their breed: Retrievers dream of chasing and finding birds, pointers point at their quarry, and terriers dream of chasing and catching balls.

They’ve also found that small dogs and young dogs dream the most. They dream short dreams because their attention spans are short; large breeds have longer and fewer dreams.

All mammals have a part of the brain called the pons, which restricts large-muscle movement at sleep. It’s what keeps us from punching our partner or the wall.

But when humans or dogs wake up during a nightmare, they can be confused about who they are, where they are, or what they’re doing. Usually, humans regain control of their limbs before they hurt anyone, but dogs can accidentally bite or strike someone before regaining full consciousness.

That’s why, to remain safe, it’s best “to let sleeping dogs lie” until they’re fully awake.


  1. I already knew this. I’ve watched Diana’s REM when her eyes were just slightly open. We’ve all seen the paw jerks or even leg movements like they are running. I’ve even heard some whines. A a puppy, Diana used to suckle in her sleep.

    What I’m amazed at is that Freyja never has night terrors after the time she spent at the shelter and her two failed adoptions. She seems to sleep quite well. But I’ve always known that Diana was the more sensitive one.