Why Do Dogs Shake, Shiver, and Have Muscle Spasms While Sleeping?by Rob Harris
Your dog is adorable when she's sleeping peacefully. As you watch and think "awwww," she suddenly starts twitching and moving her paws. Instead of panicking, enjoy watching your pet as she dreams and wondering what she's dreaming about. Dogs dream in a similar fashion to people, and their bodies often mimic tiny movements occurring in their dreamworld.
When Dreams Occur
Just like in people, dogs don't dream every second they're asleep. Dogs must leave light sleep, often called slow-wave sleep or SWS, and enter deeper sleep known as rapid-eye movement, or REM. Sleep comes in cycles, and your pooch enters and leaves the REM state several times during the night or nap time. Although your dog might have tiny dreams during SWS, she's unlikely to twitch or shake; the dreams aren't as vivid as those during REM.
People typically cycle into REM sleep every 90 minutes, according to USA Today's Paw Print Post. Dogs enter REM sleep at different intervals depending on their sizes. Smaller dogs tend to dream more often than larger dogs. Small dogs might dream for a minute or so every 10 minutes, while large dogs might grab five minutes of dream time every 45 to 90 minutes. Dreaming is necessary for dogs' -- and our -- mental health, so there's no need to wake your dog if she's shaking or shivering while asleep. It will only last a few seconds, so it's best to give her the restful sleep she needs.
Movements and Noises
Dogs make a variety of movements while dreaming. Many dogs twitch their paws or jerk their legs as if they were running. Some shake their whiskers or pull up the corners of their mouths -- perhaps growling at the squirrel that got away earlier in the day. Dogs with specific training, such as pointers, might actually assume an abbreviated version of a pointing position while dreaming. They also make noises, such as whines, yips and small barks. This doesn't mean they're in distress; noises are a normal part of dreaming.
A small amount of twitching is normal when a dog sleeps, but continued muscle spasms might not be. Even the largest dogs only dream for a few minutes at a time, so watch the clock if you're concerned about your dog's movements. If they continue for more than five minutes or if you notice similar twitches when your dog is awake, it's time to contact your vet. Involuntary muscle movements might signal a medical condition that requires immediate treatment, such as a neurological disorder, organ failure, toxin ingestion or a reaction to medication.
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