It amazes me that this is nothing to worry about. It really looks like an asthma attack. One of my foster dogs had a really prolonged episode of it, the morning I was supposed to deliver her to her new owners! Scared me to death, but when I called the vet they laughed at me, said it was nothing to be concerned about. My beagle had it too, but just short episodes. Looks painful too, besides being painful to watch.
"To my mind, I hold that the more helpless a creature, the more entitled it is to protection by man from the cruelty of man."
"The greatness of a nation and its moral progress can be judged by the way its animals are treated."
Golden Retriever Rescue of North Texas