His eyes are closed but his legs are moving as if something or someone is chasing him, or he's chasing them! His breathing is heavy, labored. He cries out! No, this is not my wife describing me having a nightmare. It's my Cockapoo dreaming!
When dogs enter a stage of deep sleep, their breathing becomes irregular and heavy and they enter the Rapid Eye Movement (REM) stage. It's in this REM state when involuntary muscle movements take place and actual dreaming occurs. And in all likelihood, they dream about the common dog activities they had during the day.
Apparently not all dogs have the same types of dreams. Small dogs dream more than larger dogs (once every 10 minutes as compared to once every 90 minutes for the larger dog.) Puppies tend to dream even more, probably due to the learning experiences they're having as new pups in the world. At night, when asleep, they mentally process all they've learned by replaying all daily activities via their dreams.
The Days of Whining & Wet Noses
Dreaming dogs display a number of outward signs as they dream. Behind their eyelids they see the objects in their dreams and react to them as if they were still awake! They whine and whimper in excitement and move their legs in a running dream state! Their noses sniff. Their breathing increases rapidly (or they hold their breath for short periods). Some dogs (I know mine does this from time to time) sleep and dream with eyes wide open!
Rats, Dogs, and Humans...Oh My!
But how do we know dogs are really dreaming? What proof exists?
Tests performed on simpler animals like rats, may aid the case of proving dogs do indeed, have a dream state.
Matthew Wilson and Kenway Louie of MIT (The Massachusetts Institute of Technology's Center For Learning and Memory) in 2001 conducted tests on the brains of sleeping rats who had been busy all day running through complex mazes. Readings were monitored and recorded from their hippocampus (the memory formation and storage area of their brain.) The researchers noted when rats slept, these same unique, identifiable patterns emerged. Rats on the run displayed patterns different from confused rats and so on. When the patterns had been reconstructed and compared, the researchers found the correlations were so close they could reconstruct where in the maze the rats would be had they been awake. They could also determine from the gathered information if the rats had been running or at a standstill in their dreams!
This research imparts to us valuable information - that rats, dogs and humans not only have the same type of electrical brain patterns but they also transition through various sleep stages from a slow wave patterned sleep to REM sleep (where dreaming occurs).
Naturally, it's a reasonable conclusion from here to assume dogs and other animals do dream, and that many of these dreams are shaped by the activities of their day to day lives. The only difference is humans can communicate with one another whether they've been dreaming and what they dream about, while dogs and rats haven't quite reached a level communication that sophisticated yet--or have they?
By Tom Matteo