OK, I saw the video, and that is what we call a reverse sneeze. It is harmless and there are a lot of dogs that do this. Sometimes our bullies will do it and my Beagle would do this when she was sniffing in the grass and got something in her snoot. It can be brought on by something they sniffed up or by allergies. This is the best way to stop it. Take two fingers and cover both their nares for a few seconds and it will stop it. It is caused by a spasm of the diaphragm and stopping them from breathing a few seconds usually stops it. So no worry, this is normal.