Bruno used to do something like this...he used to sound phlegmy and throw up quite a bit. We actually had a time when he would wake up in the middle of the night and throw up. We discovered that it was the food we were feeding him. It took us almost a year to figure out what food he could eat. It wasn't until I found this forum that we found out that a lot of the different foods we were trying weren't that great, especially for bullies. So, we put him on Fromm's Salmon a la Veg and haven't had many issues with phlegm or vomiting...unless he is super excited and panting for a long length of time...then we get the nice frothy foamy vomit . The only other thing I can think of is it could be allergies to something??? Bullies are sometimes hard to figure out...and they definately have more quirks than the average dog!