“Let sleeping dogs lie” is a well-worn maxim for a reason: Waking a dog from sleep is best avoided, as it can cause alarm, confusion and disorientation in the dog. Structurally, a dog’s brain is similar to the human's, suggesting that it repairs and reinvigorates itself in much the same way as humans' do. Dogs display brainwave patterns that are similar to humans' during sleep, which is a potential indicator that they dream when asleep.
Although dogs tend to sleep more frequently than humans, they do exhibit highly similar patterns of sleep. They begin with a light sleep, which may be stop-start as they attempt to get comfortable. Once they drift off into a deeper sleep, the display rapid eye movement sleep or REM sleep. This phrase of sleep is where dogs likely begin to dream. Since most dogs can’t tell you what they dream about, you're left with pure guesswork. Many owners will speculate, nevertheless, based on the involuntary movements their dogs perform during sleep, that they know what their dogs are dreaming about.
Dr. Stanley Coren, a psychologist and author of the book "The Intelligence of Dogs," believes that dogs most probably do dream. He believes it is probable that dogs dream about everyday events, just like humans do. One dog owner who corresponded with Coren on the subject strongly believed he had witnessed his dog dreaming about having a bath, as the dog’s actions performed in the dream and immediately upon waking were identical to those actions performed during the bath.
The video of the sleepwalking dog who awoke and ran head-on into a wall went viral in 2009. In the video, the dog can be seen moving his legs as if sprinting while actually asleep on his side. The dog then wakes, stands up and continues to attempt to run -- but the attempt is abruptly curtailed by a rather solid wall. This video, combined with studies of brain activity and other physical evidence would suggest that some dogs perform walking in their sleep. However, this behavior is distinct from the human phenomenon of sleepwalking, a condition whereby the person is in a state of semi-consciousness and is capable of performing manual tasks while in a sleeplike state.
Other Sleep Activity
Dogs growl, bark, whine, shake, kick and wriggle during sleep. No evidence exists to suggest that dogs can perform tasks such as eating while asleep, but they certainly mimic the actions associated with eating while asleep. Young dogs and small breeds are more prone to acting out day-to-day actions during sleep. Young dogs are prone to falling asleep during an activity such as eating, often with their heads or entire bodies in their food bowls; they may wake and continue to eat, albeit perhaps in a drowsy state. This behavior may be mistaken for so-called sleep-eating.