Have you ever noticed your dog twitching, growling, or crying in their sleep? If so, you probably assumed they were dreaming and then stopped and questioned if dogs can really dream. Well, according to Psychology Today, they can. They also state that dogs have very similar brain waves and electrical activity as humans and that evidence has shown that even animals that are not as intelligent as dogs dream, so it would be odd if dogs did not. Psychology Today also says that Matthew Wilson and Kenway Louie from the Massachusetts Institute of Technology performed a study on rats that measured their brain waves while going through a maze during the day and then measured them again while sleeping. They found that the patterns of the brain waves during both events were the same, which is consistent with the common idea that we dream about what we did that day. They state that there is evidence that dogs do the same.
In a study done to figure out the movement of dogs in their sleep, Psychology Today says that dogs did not move until they were in the stage of sleep that they would begin to dream. They also said the study inactivated the pons of some dogs, which is the part of the brain that keeps us from moving while dreaming, and the dogs began to move much more. The study also found that certain types of dogs acted out things that were specific to their breed; things they would do in real life.
Psychology Today says that if you pay close attention to your dog about twenty minutes after they fall asleep, their breathing will get shallow and you may even be able to see their eyes moving underneath their eyelids. This is them watching their dream.
So pay close attention! If you notice your dog crying or looking like they are trying to run, give them a little shake! They may be having a nightmare! (Total theory of my own.)