I have a 13 year old Yorkie who is having the exact same problem as you have described.
I have taken him to the vet twice to be checked out because I was afraid he had a tumor or some kind of blockage in his nasal passage. The vet told me twice that he is fine.
The first time I took him to the vet, the vet held a small square pane of glass under one nostral and put his finger over the other nostral to block air as a way to see if the unblocked nostral would fog up the pane of glass. The vet did this for each side and determined all was fine. Well, a few months later I took Cid back because I was still convinced something was wrong and the vet did exrays and again told me all was fine. The breathing is still heavy when he is in a resting state and I am still convinced something is not right. The same thing happens to be at night when I hear my dog snorring or breathing so hard, he looks at me like "leave me alone, I am sleeping"! |