Canines spend most of their lives sleeping. The National Sleep Foundation reports that dogs sleep 12 to 14 hours each day. A question that comes to mind when we see a dog sleeping is: do dogs dream? According to research, they are very likely to dream.

What Happens When Dogs Sleep?

Although we cannot enter a dogs' mind to know if they are dreaming, we can rely on sleeping studies performed in dogs and other mammals to understand what happens when dogs are sleeping.

Research led by Matt Wilson, Ph.D., a neuroscientist at the Massachusetts Institute for Technology shows that sleep behaviors are similar among various mammals. For example,  rapid eye movement (REM) associated with dreaming in humans also occurs in dogs.  In addition, both dogs and humans manifest increased levels of brain activity while they are asleep.

One of Wilson's experiments consisted in recording the activity pattern of brain cells of rats while they were moving through a maze and when they were in REM sleep. The scientists then compared both patterns and found out that they were very similar; as if the rat was dreaming about the maze. This and other findings have led researchers to believe that rats (and probably other mammals) can dream and that, when they do, they dream about things that happened during daily life.

Have you ever wondered why we do not move while we sleep? The answer to this questions relies on a part of the brain called the Pons Varolii (or just the Pons) which hinders movement during sleep, essentially causing muscle paralysis. To better understand the function of this part of the brain, scientists inhibited the Pons' function in cats and observed them during sleep. As it turns out, the cats began moving and some walked in their sleep. This suggests that the cats were acting out what they were dreaming.

What Do Dogs Dream About?

Wilson’s experiments with rats strongly suggest that animals dream about things similar to the events they experienced during the day, just like humans tend to dream about what happens to them. So your dog may dream about their walk in the park, chasing a ball, playing with other dogs or having their favorite meal.

An interesting article published in Psychology Today includes an anecdote of a reader who ascertains that his dog was dreaming about having a bath and he was sleep-walking. The dog owner observed how his dog was hiding as he usually did when he knew a bath was coming, while he was asleep. 

References:

Morrison, A. (1993). Mechanisms underlying oneiric behavior released in REM sleep by pontine lesions in cats. https://doi.org/10.1111/j.1365-2869.1993.tb00052.x

Coren, S. (2010). Do Dogs Dream? 

Wilson, M. Massachusetts Institute of Technology (MIT).

https://cbmm.mit.edu/about/people/wilson