How can I help a dog breathe easier?

The English Bulldog I am caring for has severe stenotic nares which make breathing difficult when he gets excited. Once the difficult breathing starts, it's takes a long time to get back under control. ...it perpetuates itself, like a reverse sneeze.

Owner says that it is completely normal and that he will breathe normal after laying down for awhile or going to sleep. Tongue is NOT purple, but it was intermittently at the Meet & Greet. Truthfully, if he were my dog, he would be in surgery for stenotic nares correction, but he's not so I'm looking for ways to help him breathe better that I can do at home.