It's possible that your dog is overheated and looking for a means to cool off. This holds especially true for canines that have thick coats of fur.
f you have ever run your hand over the fur that covers the stomach of your dog
vyou are aware that it does not offer much protection from the weather.
When dogs are active, they produce a lot of internal body heat, and it is easy for them to overheat
especially when the weather is warm and the sun is shining. Your dog can relieve some of that heat by lying on their back in the shade and running
get there as quickly as possible.Imagine that you are wrapping yourself in this.
Your dog appears to be wrapped in a massive blanket, with the exception of their tummy.
The hair on their stomach is fine, thus there is less resistance to the flow of heat away from that area.