I do not have any answers for you but my 6 year old male piggy Blizzard has a similar issue. It has been happening for about 8 months now and it is just the most awful sound when it happens. He got X-rays which revealed a very slight swelling in the ear canal so we tried Baytril and it seemed to go away. Since then it keeps returning and we have tried antibiotics another 3 times and X-rays again. The wheezing always comes back so at this point the vet and I have decided to leave it alone since he still acts totally normal energy wise and appetite wise. I am interested to see if you find out anything else.