hi there :)

my boston lucy has the exact same situation. whenever she gets overly excited, she goes into these breathing fits, almost like she has asthma, but she does not look like she is in pain or panicking. i mentioned it to my vet, who assured me that it's alright. unless you feel that your dog is suffering, i don't recommend having anymore surgery's done. a second opinion also helps. cheers!

my boston has the same thing only last a minute or so its scarey. i called the vet and he said it would help if my dog lost weight. and that with the smuched in nose it is normal he did say he could have a surgery but i just dont know if i want to go that way yet. i have two bostons one is turning 4 in april (which i am talking about) and the other is under a year and does not do the breathing thing.

Both my Bostons do this and I've been reassured that it's nothing to worry about.
I clipped this from a web page:

Paroxysmal Respiration or "The Reverse Sneeze"
"This is a misnomer, for it has nothing to do with actual sneezing. However, it is a popular term for something that appears to be worse than it actually is. When this occurs, your dog will appear to be snorting or choking. The posture will be one of the neck extended with the chest expanded, as the dog struggles to take in air. The actual physiology is that the trachea has narrowed and the normal amount of air is not able to enter the lungs. The triggering mechanisms are usually excitement or stress. If this is happening to your dog, do not panic. You can help your dog by soothingly stroking the upper throat area to encourage relaxation and dilation of the trachea. If things do not resolve soon, and the dog is really having a continued hard time, you can try depressing the tongue to open up the oral cavity for the passage of much needed air into the lungs. The predisposition to this is thought to be hereditary, particularly in smaller breeds because of the decreased diameter of their tracheas. If your dog occasionally has this, do not worry that you need to be there to help each time it happens. A dog is able to come out of an attack of reverse sneezing without help and will not suffer permanent damage. Contributed by Barbara Moore's Veterinarian"

the others' responses are correct -- it's no huge deal. it's just a "reverse sneeze," as they call it (or paroxymal breathing).

my boston does this a lot when i have him on leash with a normal collar, because he pulls too hard and it squishes his trachea. i have a little trick for stopping the reverse sneeze: just cover your dog's muzzle (mouth and nose) with your hand for a moment. the reverse sneezing will stop almost immediately. works like a charm.

my other trick is to use a pronged collar -- it *looks* painful, but it actually disperses the pressure when he pulls among many separate points around the neck instead of all in one central spot over the trachea, which prevents the reverse sneeze in the first place.