To Sleep, Perchance to Dream
Why do dogs twitch in their sleep?
Twitching is an involuntary muscle spasm that occurs rapidly and suddenly in almost any part of a dog’s body. These movements typically happen in the back legs while your dog is sleeping. Puppies and senior dogs tend to twitch in their sleep more than other dogs. Experts agree that in most instances, sleep twitching is completely normal.
Some common reasons for dog twitching while sleeping include active dreaming, deep sleep, growth development, muscles relaxing, memory consolidation, being startled or exhaustion. Like us, as dogs start to fall asleep, their muscles relax, and they may jerk unexpectedly. Some twitches are so strong, they may even wake up your dog.
Sleep twitching is often an indication that your dog is dreaming or has been startled by a noise. Dogs, like humans, have sleep cycles that include both REM (rapid eye movement) and non-REM sleep. REM sleep is also called “active” sleep. During this phase, brain activity is high, the heart rate speeds up, breathing is irregular, and dreams most often occur. This is the period of the sleep cycle when your dog is likely to experience twitching.
During the REM sleep cycle, an area of the brain called the pons controls muscle movement. However, sometimes it is temporarily ineffective, leading to your dog twitching in his sleep. The problem is more prevalent in young puppies, where the pons is underdeveloped, and older dogs, where the pons is less effective.
Do dogs dream?
Since we cannot exactly ask our dogs this question, science has come up with some interesting ways to determine if dogs and other animals dream.
A study found that laboratory rats that were trained to run in a maze exhibited brain activity during REM sleep that was similar to when they were actually in the maze. This led researchers to conclude that the rats were dreaming about the maze they had run in earlier. The data was so precise that the scientists could determine where in the maze the rat was dreaming about just by looking at the unique signature of the rat’s brain activity.
The structure of the brains of dogs is similar to humans’ brains. During sleep, the brain-wave patterns of dogs are similar to those of humans and go through the same stages of electrical activity. These are consistent with the idea that dogs do dream.
You can determine when your dog is dreaming. About 20 minutes after an average-sized dog falls asleep, his first dream should start. His breathing will become shallow and irregular, and there may be muscle twitches. His eyes might move behind his closed lids, because the dog is looking at the dream images as if they were real. When people are awakened during this REM sleep phase, they usually report that they were dreaming.
While dogs are deep in sleep and dreaming, they may look like they are running, jumping or swimming. They may whimper, whine or cry out. They may be having a nightmare. Disrupting a dog during REM sleep may startle him and cause him to bite or scratch involuntarily.
If you feel the need to wake a sleeping dog, it is better to call his name loudly or make a noise, such as clapping or dropping an object on the floor. Then you can reassure him when he awakens.
What if my dog is having a seizure?
Sometimes twitching is not related to sleep at all. Twitches can be caused by muscle or nervous-system disorders and seizures. While dreaming, dogs may twitch, paddle or kick their legs. These movements are intermittent and brief, lasting less than 30 seconds. When dogs are having seizures, their legs tend to be stiff and rigid with more violent movements.
Most dogs will have a seizure while awake or shortly after waking up. Some dogs may seizure when they are asleep. Actively seizing dogs are hard to awaken. Dogs may also urinate or defecate during a seizure, but dreaming dogs will not. After a seizure, you may notice the dog drooling, panting or acting disoriented.
Seizures can have a variety of causes, from epilepsy to cancer. Talk to your veterinarian if you suspect your dog may be having seizures in his sleep instead of dreaming. If your dog is continuously convulsing for 30 seconds, you should seek emergency veterinary care. However, if he simply kicks the air a few times, that is considered perfectly normal.
Is it weird that my dog’s eyes are open when she is sleeping?
While it might appear a little strange, some dogs do sleep with their eyes open occasionally. Dogs have a third eyelid that is often visible as they sleep, so it can look like the eye is open when it actually is not.
The third eyelid is also called the nictitating membrane. It lies behind the outer eyelids, and cleans and protects the eye. Every time the dog blinks or closes the eye, this membrane automatically sweeps dirt and debris from the surface of the cornea. When the eye opens, the membrane retracts to the inner corner of the eye.
Another explanation for dogs sleeping with their eyes open has to do with dogs’ survival instinct. It is felt that they are giving the appearance of keeping a watchful eye on their surroundings. Many species of animals have developed this skill. It allows them to stay partially alert during sleep and serves to trick predators into believing they are awake and discourage attacks.
Narcolepsy is a neurological disorder that disrupts the sleep/wake cycle. It is another condition that can make it seem like your dog is sleeping with his eyes open. Doberman Pinschers, Poodles and Labrador Retrievers are genetically predisposed to narcolepsy, but other breeds can also experience it. In a narcoleptic event, a dog will fall to the ground suddenly and seem to be in a deep sleep.
It helps to understand a dog’s sleep patterns to determine why his eyes may be open when he sleeps. The first phase is called slow-wave sleep, during which the heart rate and breathing slow. The next phase is REM, during which the eyelids typically close and deep sleep occurs.
Eating patterns will also affect sleep patterns. When dogs only eat one meal a day, they are likely to sleep less and sleep lighter than dogs that eat smaller meals more often throughout the day.
Sleeping with the eyes visible is normal and does not require medical attention. However, if your dog is having seizures or narcoleptic events, you should see your veterinarian immediately.
There are a few signs to look out for that might point to something more severe happening. If your dog falls asleep at unexpected moments while playing or eating, sleeps with his eyes open, even if they look red, swollen and itchy, or is unable to hear or respond to his name even though his eyes are open, a more serious problem may be developing. These situations should be monitored, and if they happen more than once, your dog should be examined by your veterinarian.