Why does my horse extend his body

My horse extends his body, in pee pee stance. Yet does not always pee. I only notice it while we are resting. Ill take a rest from riding while still under saddle. He will then extend his body in pee stance but doesnt always pee. So strange was wondering if this related to health issue?

Isn't this the horse that's having riding issues? You were going to have a chiro look at him weren't you? It could be due to a bladder issue or it could be a muscle or adjustment required issue.

I've ridden an older horse that was diagnosed with Cushings. He did that. The vet said the Cushings made him "think" he needed to pee all the time.