How do dogs and cats dream?

Dogs and cats dream just like humans. They experience nightmares or pleasant memories, and their daily experiences shape the content of their dreams. These beloved household pets share sleep patterns with humans, including the REM (Rapid Eye Movement) phase, which is associated with intense brain activity and dreaming.

“The patterns of brain waves during sleep are the same in people as in other mammals,” explains Juan Antonio Aguado, a veterinarian at the Montepríncipe Clinic in Madrid. “Dogs are likely to dream about their owners, the walks or the games they play during the waking state; and cats might relive moments of cuddling on the sofa, hunting prey, or even fights with other animals. These dreams manifest in physical behaviors during sleep, such as mouth twitching, leg movements, growling and barking.”

The size and age of animals influence their sleeping habits. “Large dogs dream every 60 to 90 minutes, while smaller dogs do so around every 10 minutes because they have more brain activity when they sleep,” explains the veterinarian.

And their sleep behavior changes over time. Older animals “can sleep more hours during the day and wake up at night,” according to the specialist. “Older dogs are also more likely to develop canine cognitive dysfunction syndrome, a neurodegenerative disease similar to human Alzheimer’s, which causes changes in the sleep-wake cycle.”

Puppies, on the other hand, have a different sleep pattern. “This is due to the growth hormone, which causes them to need to sleep more so that the brain replenishes energy to develop, just like babies do,” explains Estefanía Pineda, a specialist in animal behavioral medicine and professor at the Department of Animal Production at the Complutense University of Madrid.

Cats, though less studied than dogs in terms of their sleep habits, are known to be exceptionally sleepy creatures. “They can rest between 12 and 16 hours a day if they are very tired and, as they are crepuscular animals, they become active at night to hunt, because even though they are domestic, they maintain their habits as predators,” describes Aguado.

The sleeping environment also plays a significant role in the quality of rest for pets. “Dogs and cats with a home where they can take refuge have a more restful and deep sleep than those who rest outdoors and have to say vigilant against the dangers that may be lurking,” says Pineda.

When it comes to dogs, the character associated with their breed also influences how they sleep: “For example, a pointer can adopt a pointing posture while sleeping, as it would do in the countryside with a partridge, and a Doberman can have a dream experience that reflects its protective behavior,” says Aguado.

Although dogs and cats have pleasant dreams, these can turn into nightmares. When this happens, “they growl, moan or bark and wake up startled, defensive or frightened,” Aguado says. Despite this, when the animal is deeply asleep it is best not to wake them, as their wareness of reality diminishes in deep sleep. “The dog or cat may react negatively and there is a risk of aggression. It is preferable to call it by name or gently move its bed to get its attention,” advises the animal health specialist.

Sleep disorders due to health problems

The 2020 study Sleep in the Dog: Comparative, Behavioral and Translational Relevance, published in the scientific journal Behavioural Sciences, describes how sleep deprivation affects dogs. Regarding this research, Pineda explains: “They showed less ability to differentiate between happy or sad human expressions and, therefore, it affects their communicative interaction with people, as well as their learning capacity.”

Certain diseases also affect sleep quality and can cause serious problems. These include osteoarthritis, breathing difficulties and metabolic disorders such as diabetes. In dogs, for example, REM sleep behavior disorder is common: “It causes violent limb movements, howling, barking or chewing and biting while the animal is sleeping,” explains Aguado.

Narcolepsy is another canine sleep disorder, although it only affects certain breeds. “Dobermans, Labradors and Dachshunds, for example, often suffer from it and have shorter periods of sleep, as well as losing control of their muscle movements,” the expert points out.

On the other hand, obstructive sleep apnea is “less common”: “It affects certain breeds such as the English bulldog, which have breathing difficulties due to their anatomy, or obese animals,” explains Pineda. “It causes breathing to stop during sleep or snoring, which leads the animal to feel tired even if it sleeps a lot.”

For dogs and cats, sleep is just as vital as it is for any mammal. Restful sleep significantly impacts their overall health and enhances their ability to learn and adapt.

Sign up for our weekly newsletter to get more English-language news coverage from EL PAÍS USA Edition