Anyone got any ideas as to what would make a friend's rottie sneeze?

Nothing up nose..vet checked.  Friend thought cigarette smoke, but she sneezes out doors, indoors, in car etc.  I suspected excitement, but she is now doing it during the night, waking up and sneezing for a good half hour.  Owner is reclutant to have a full check (under aneasthetic) done, as it is not making her ill.  Just thought it would be worth asking if anyone had experience of this.

has she ruled out the obvious... any of those 'ambi pur' type 'plug in' air freshners in the house? they can be quite potent (trigger my Asthma) and things like shake'n'vac too...
Just a thought.

I once had 3 of my dogs go down with continual sneezing.  Vet asked me to check out anything they could have gotten to - and I found a large sack of peanuts (for the wild birds) ripped open in my garage.  They had eaten loads!

hello,

my stb puppie started to sneeze all the time but it seems to worse at night. some blood started to come out as she was sneezing. took her to the vet and he told us that it might have been the grass in the park so if your dog is going to the  park it might be worth checking it out. we put our dog on antibiotics and been avoiding long grass in the park and now she's fine.