Generally, a dog sleeps from 12 to 13 hours everyday. A dog therefore spends more than half of its life sleeping! The dog may be lying down on a hole in the ground it has dug, on trampled vegetation or on a comfortable dog bed but one thing is for sure the dog would instantly be alert when it has scented prey or an intruder. Dogs sleep a lot but they are light sleepers, one that would wake up instantly when even the slightest sound is heard.
A dog may sleep on its side, some do on their stomach. Some breeds like the Doberman Pincher and the Corgi takes the flying frog or the flying squirrel potion when they sleep. The dog would lie down on its stomach with the hind legs stretched out. Dogs take varied position when they sleep though the most amusing stance is when they sleep on their backs. Why do dogs sleep on their backs with the four paws up in the air? The dog would look like an upended table! Surely, it can not be because the dog is taking into consideration the possibility that the ceiling will fall down. It is most likely that the dog is asking you to give it a belly rub.
Actually, when a dog sleeps on its back it can be because the dog is trying to cool down. We know for a fact that dogs have a hard time cooling themselves given that they only sweat through the pads in their paws. Dogs pant to adjust the body temperature. This is probably one of the reasons why dogs sleep on their back. The belly after all is less covered with fur hence when it is exposed to the air the dog will get cool. Sleeping on its back allows the dog to be comfortable as the body will be most relaxed unlike when the dog is sleeping all curled up and the muscles are tense. It can be noted that dogs only sleep in their backs when they are most secure like when they are inside the house or in their own sleeping quarters. Dog experts have noted that dogs in the wild do not assume this position when they sleep as this is considered to be the most comfortable sleeping position. Dogs in the wild would need to be constantly ready for predators, to be alert the instance a predator is scented thus they dare not sleep comfortably on their backs. Although it feels good they would not dare lie on their back when they sleep as they would be exposing their throat, the stomach and the heart for any possible attack.
A dog that lies on its back when it sleeps is a sign of submission. Your pet could be deferring to you or to the family which it considers to be higher in the dog hierarchy. Dogs are pack animals. They expect to have a leader they can look up to. However, a dog sleeping on its back with the forepaws covering its chest wants to have sometime for itself. The dog is trying to convey a DO NOT DISTURB message. This position indicates withdrawal. In this instance let the sleeping dog lie if you do not want to be startled by the dogs growling and be at the end of the dogs strong and sharp teeth.