By Nicole Pajer
Have you ever looked over at your sleeping dog and noticed him move his leg or twitch? You are not the only one. Veterinarians will tell you that, for the most part, this is a very common occurrence and is nothing to be alarmed about. In rare instances, however, twitching may be a warning sign for an underlying disease or condition. To get to the bottom of this phenomenon, we asked the experts.
Why Do Dogs Twitch in Their Sleep?
According to Dr. Stanley Coren, a former psychology professor at the University of British Columbia and neuropsychological researcher, the main reason that dogs twitch in their sleep is that they are dreaming. “The twitching that you see in a sleeping dog is usually a normal behavior and is not anything to worry about,” he says.
Dr. Diarra Blue, a Houston-based veterinarian who stars on Animal Planet’s The Vet Life, agrees. “Dogs have a normal REM cycle of sleep just like we do, so when they get to that deeper level of sleep, they actively are having dreams,” he explains. “Whatever that dream is—whether they are chasing a little cat in their dream or they are asking for some good food or running a marathon—they can twitch and you can see muscle movement, just as you would in humans.”
From his research, Coren has deduced that sleep twitching most commonly occurs in younger and older dogs. “During the REM state of sleep, animals tend to dream and their eyes move around behind their closed eyelids. During this dream state, the large muscles, which tend to move our bodies around, are turned off,” he says, noting that if this did not happen, then we would act out all of our dreams.
An older part of the brain called the pons, a protrusion that is high up on the brainstem, contains two small “off” switches, Coren continues. “If either or both of these ‘off’ switches is not fully developed or has grown weak due to the aging process, then the muscles are not completely turned off and during dreaming, the animal will start to move. How much movement occurs depends upon how effective or ineffective these ‘off’ switches are.”
Blue adds that a dog’s level of activity does not affect how frequently he sleep twitches. While pet parents may notice puppies moving around in their sleep more often, this has not yet been extensively researched, he notes. “I don’t know if that’s because we tend to pay more attention to our puppies because we are all lovey-dovey and we just got them or if they actually just dream more,” he says.
How Often Do Dogs Dream?
According to Coren, an average-sized dog will dream about every 20 minutes and the dream typically will last about a minute. “You can see an oncoming dream state because the dog’s breathing becomes irregular and you can see the eyes moving behind the closed lids (which is why this stage is called the rapid eye movement stage or REM for short),” he explains.
The length and frequency of these dream states depends on the size of the dog, he adds. “Larger dogs have fewer dreams but they last longer,” Coren says. “So a St. Bernard might have a dream state every 45 minutes and they will last for four minutes in length. Smaller dogs, like a pug, might have a dream every 10 minutes, and these might last less than 30 seconds.”
Twitching behaviors will only occur during these dream states, Coren notes.
When Is Sleep Twitching a Cause for Concern?
While sleep twitching is typically nothing to worry about, there are some cases where the movement can be a cause for concern. Dr. Kathryn Primm, owner of Applebrook Animal Hospital in Tennessee, says that sleep movement can become problematic if the twitching begins to interfere with a dog’s sleep. “Dogs can suffer from narcolepsy and other sleep disorders, so if you think that the twitching is excessive or interrupting, you should see your vet,” she says. “Occasional twitching is nothing to worry about, but if your dog is not able to sleep and is constantly awakened by the twitching, there could be trouble. If twitching occurs frequently in an awake pet, it is definitely worth mentioning to your vet.”
Excessive twitching can also be due to a neuromuscular condition, such as tick paralysis, seizure activity, or an electrolyte imbalance due to malnutrition, Blue adds.
Normal twitches occur with a dog typically lying on his side, paddling his paws, and possibly making a little twitch or jump here and there, Blue describes. “They are typically still lying flat but they are possibly making little noises. That can be very normal.”
If your dog is paddling and then that goes into full body shakes—the body is convulsing, he loses control of his urine or bowels, or he has froth, foam, or vomit coming from his mouth—then it’s abnormal, Blue says. “If you try to wake them in one of these twitching bouts and they don’t actually wake up or if they do wake up and they seem really dazed or out of it, that’s usually something we see post-seizure activity,” he explains.
Pet parents should monitor their dog’s twitching to make sure everything is normal, our experts advise. “If you are ever concerned, as a part of their annual examination with their veterinarian, I would recommend doing blood work to make sure that their electrolyte and all other values involving their body organs are within normal limits,” Blue says. A veterinarian can also take a full health history and perform a physical and neurological examination to help determine whether a dog’s twitching is anything to worry about.