I had a 6 year old (45 pound) Border Collie who had all the same symptoms (except the bloating) and I immediately took him to the vet who diagnosed him as having a Hernia. How he got a Hernia I have no clue. My dog had surgery and recovered very nicely. The surgery though, was rather expensive but well worth it as my dog lived almost another seven years. This may not be the case with your dog, but you must have your Vet check him out.
My dog is having a problem with his bowel movement. He is walking around in circles in the pooping position, but nothing is coming out. He does not seem to be in any distress. What should I do?
Bloat is a serious medical condition that can kill digs it's where food water and air get trapped in the stomach so get your dog to a vet ASAP