Did she have the kennel cough (bordatella) vaccine 6-8 weeks ago? If yes, it really would make me think she does have it...and it *can* take weeks-months to get rid of it for some dogs. As for your other dog, is she older and/or vaccinated against KC? That may be why she isn't getting it (if that's what this is).
The other thing though is that you said it happens upon exercise and/or at night - so, that could be reverse sneezing, a narrowed trachea, a soft palate irregularity...or collapsed trachea (but not sure it sounds like the last one based on what you've said).
When it happens at night, was she snoring beforehand? If yes, it could be a soft palate issue...
__________________ ~ A friend told me I was delusional. I nearly fell off my unicorn. ~
°¨¨¨°ºOº°¨¨¨° Ann | Pfeiffer | Marcel Verdel Purcell | Wylie | Artie °¨¨¨°ºOº°¨¨¨° |