How can you tell your sleeping dog is in the non-REM (deep sleep) stage?FamilyPet
Dogs have similar sleep stages to humans, with a REM sleep stage and a deep sleep stage. When a dog first falls asleep, he enters into a sleep stage where he is lightly sleeping before transitioning into deeper stages of sleep. When a dog reaches stage four of the sleeping cycle, he has entered into a deep sleep.
In the deep sleep stage, a dog will become completely relaxed. It’s easy to tell when your sleeping dog is in the non-REM, deep sleep stage because he or she will have a decreased heart rate, decreased body temperature, slower breathing and generally be oblivious to anything going on in their surroundings. If you try to rouse your dog out of this deep sleep stage, he will often jerk awake suddenly, and seem disoriented or confused. A dog awoken out of the deep sleep stage generally will try to fall back asleep almost immediately.
A dog in a deep sleep stage will often position himself into a naturally comfortable position. While some dogs prefer to sleep on their stomachs, others will sprawl out on their sides or curl up. When a dog exits the deep sleep stage and transitions into REM sleep, their behavior may include twitching, audible noises and eye movement.