What I would do first is watch the dog to see if it even does that before going to sleep because I have never seen a dog do that before going to sleep and I had 2 dogs before and both of them were pit bulls and puppies
In the scientific method first of all is you need to identify the problem, the problem to your question is why does the dog circle its bed before lying down. Second is the observation to gather some data, you need to observe the dog if what could be the possibility the the dog may do that action. The third is the pre hypothesis, you need to came up with an idea why does the dog do such and action for example the needs to find a correct spot to make itself comfortable and lastly the hypothesis, this should answer to your question or your problem. So my hypothesis is that dogs are one of the animals that are those difficult to find a place to sleep and some of that kind of animals are cat, before they lay on their bed, they have to circle to find a spot that could fit its body to be more comfortable when the dog sleep
