It sounds like there is something restricting its breathing. Did it eat anything such as a treat that part of it could have gotten caught in its airway? My Doberman sometimes hacks and then vomits when she eats her dinner too fast. 3 days ago it lasted for 2 hours. Try opening his/her mouth and blowing in it real fast and then rubbing its throat. I learned that trick as a child when I used to show dogs. It also could be some hair. If it gets worse call the vet just to be safe.
