The short answer to whether dogs dream, is yes.
Yes, they dream and it’s probably very similar to the way we dream. People have two types of sleep states, REM and non-REM. Most of us remember the dreams we have during REM sleep. It’s these dreams that tend to be more memorable. That’s partly because they tend to be more bizarre and partly because we tend to wake up immediately following a REM cycle, making the REM dream the last thing on our mind as we re-enter the waking world. It turns out, scientists have tested animals and confirmed that non-REM sleep occurs in mammals, all vertebrates, and even some invertebrates, like fruit flies. Studies, such as the 2001 study at the Massachusetts Institute of Technology also looked at brain patterns of their animal subjects and learned that the brain revealed similar activity, such as play, while they were sleeping as when they were awake. Dogs not only get non-REm sleep, but they will enter REM sleep about 20 minutes into a nap. They’ll get their REM dreams for about 2-3 minutes and then cycle back into non-REM sleep. During their REM cycle, their brain showed patterns of dreaming, very similar to humans. Tests at Stanford indicated sleep patterns, brain activity, and biochemistry during sleep, all clearly showed that dogs dream.
What are dreams like for dogs?
Those same tests at Stanford not only revealed that dogs dream, but it showed they have nightmares. They can even develop sleep disorders, such as narcolepsy and cataplexy, which will affect their memory and ability to learn, just like humans who experience sleep deprivation. In fact, according to brain imaging, both dogs and cats probably have very similar dreams as humans except they dream about the things that occur in their day and life experiences. They may dream of running through open spaces and fields of green - if they’ve had that experience. They may have dreams about going for walks, getting treats, and receiving praise from their guardians. And, according to studies on psychology and behavior , the electrical activity of a dog’s brain while in non-REM and REM sleep, shows that they definitely have nightmares. They could be about the two-year-old who terrorizes them and pulls their tail, or maybe about the house cat that won’t let them walk up the stairs without getting a swift paw to the face. Without being able to talk to dogs about their dreams and what they remember, we can’t be sure of the details, but because of their brain activity, we can be sure they have dreams about their daily activities that can sometimes take a turn to the nightmarish.
What do we do if we think our pup is having a nightmare?
It’s so adorable to watch those flicking paws and to see that build to an all out sideways chase while they sleep. Waking them up may not even come to mind because of the cuteness factor while watching them dream. That’s a great instinct. And when we know they must be having a nightmare because of the little sounds they make or the bad day they had, it can also be our instinct to relieve them of the discomfort of a nightmare and gently wake them. That’s okay, but we should be aware that wakeing a dog from his or her REM cycle can be startling for them. They may not be able to adjust as quickly as we can, from the dream world to reality. It can be confusing for them. The bottom line is that dogs need their sleep, just like humans. Make sure they get regular sleep in an environment that is healthy and encourages deep sleep. A household dog that is always on edge or a working dog who is always on duty, such as protection animals who don’t get off-duty time, can end up with sleep dysfunction. Lack of quality sleep can make working dogs less effective and household dogs can become irritable or miss out on learning opportunities. 
Of course, we don’t want them to have to go through nightmares if we can help. Placing a gentle hand to ease them out of a bad one is probably OK. But overall, not only to dogs dream, but sleep is incredibly important, so disruptions should be kept to a minimum. If you feel like your pooch has the right environment for a good night’s sleep, but Fido is experiencing anxiety that keeps them on edge and wakes them up often, consider working with a talented trainer who can help you determine the root of their anxiety and how to help. If your pup is having a difficult time getting sleep, but doesn’t seem to suffer from anxiety, consider a vet visit to check for a sleep disorder.
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