Shelties have an amusing trait of sleeping on their backs, legs akimbo. It's not a unique trait to the breed (plenty of dogs do it!) but they do it with a certain pizzazz.
Recently I asked Sheltie Planet readers to submit their Shelties sleeping on their backs and looking oh-so-relaxed. Here are the highlights...

Shameless Kodi loves sleeping on his back
From Barb Vaughan via Facebook

Bella and Amy snuggle up together
From Tina Towers via Facebook

4-month-old Jasper gets comfortable
From
Bluebell via our Sheltie Forums

Howard and Piper cozy up on their backs
(My own boys caught on camera)
Shelties sleep in all different positions - on their sides, on their bellies, curled up with their nose in their tail, and sometimes on their backs with all four paws sticking up in the air. So, why do they do it? Is it really that comfortable?
Yes, apparently so! Lying sprawled out on their backs shows they are super relaxed and have their guard down. In dog psychology, this position is submissive which means they've diverted to another pack leader. It also shows they are feeling fully safe and secure by allowing their vulnerable body parts (chest, throat, stomach) open to attack. This is still an important instinct for dogs who, although domesticated, still maintain many of their wild instincts at the gut level.
Another reason Shelties sleep on their backs may be to cool down. Unlike humans who sweat all through their skin, dogs can only sweat through the pads in their paws. They also pant with their tongues out to cool down. Since the belly has the least amount of undercoat, sleeping belly up can also expose the skin to cool air.
If your dog is fast asleep on his back, it's best to adhere to the old saying "let sleeping dogs lie" - lest you disturb his blissful slumber. However, if your Sheltie is awake and playing, rolling on his back is often a request for a belly rub!
About The AuthorBecky Turner is the creator of Sheltie Planet. She lives in New Zealand and also runs the websites World of Lucid Dreaming and Improve Vision Naturally. Becky is 100% owned by Howard and Piper Woofington Moon. Visit her on Facebook or her Sheltie Forums.