My older bully Bruno is a much louder snorer and breather than my younger bully Bunker. Bruno gets phlegmy quite often (especially when playing) and often coughs (sometimes coughs up a little phlegm/mucus). I have yet to see this with Bunker. We took Bruno to the vet because of this...we were afraid he had an elongated soft palate, but the vet didn't seem to think so (yay!). But I will tell you that when we changed Bruno's food to Fromm Salmon a la Veg, this problem has lessened quite significantly. I think some bully's, especially those with a more pushed in face, are just louder breathers. I know some bully's also have a problem with the nares being to small, requiring a surgery to enlarge them. Other than those things, I can't think of anything else! Good luck to your little Molly!