When your dog's day is over it dreams of you, says Harvard psychologist

But your cat is more likely to just be dreaming about mice

This dog is probably dreaming about her owner (Getty Images)

Dogs probably dream about their owners while they sleep, an expert has said.

Dr Deirdre Barrett, a Clinical and Evolutionary Psychologist at Harvard Medical School, has spent years studying sleep behaviour in humans.

Extrapolating from her work with people, she said it is likely dogs dream about their everyday experiences, just like humans.

“Humans dream about the same things they’re interested in by day, though more visually and less logically,” Dr Barrett told People.

“There’s no reason to think animals are any different. Since dogs are generally extremely attached to their human owners, it’s likely your dog is dreaming of your face, your smell and of pleasing or annoying you.”

She cautioned there is no way to know for sure what dogs see when they dream, or even if they dream at all, but said most mammals have a similar sleep cycle to humans, going into a deep sleep stage, in which the brain is much less active, and then into periods of activity called Rapid Eye Movement (REM) sleep, in which dreams occur for humans. "That certainly makes it the best guess that other mammals are dreaming, too," she said.

But while dogs dote on their human companions, cats maintain their waking aloofness when they sleep.

“We actually know more about cats dreams, because one of the earliest sleep researchers, Michel Jouvet, destroyed the tiny area in cat brains that inhibits movements during REM sleep," Dr Barrett said. "Cats lay quietly through the other stages of sleep, and when REM began, they leapt up, stalked, pounced, arched their backs and hissed. They looked like they were hunting mice in their dreams.”

Dr Barrett confirmed that dogs too are probably acting out their dreams when their legs move in running motion in their sleep.

The psychologist also offered advice to pet owners who want to make sure their animals have good dreams.

She said: “The best way to give ourselves or our children better dreams is to have happy daytime experiences and to get plenty of sleep in a safe and comfortable environment. It’s a good bet this is also best for pets’ dreams.”