Salivary cysts do seem to be more common in ANs. We have drained one (for someone else) before, but had to do it regularly, once a month or every 3 weeks. Once they get older, they normally improve as the tubes seem to get bigger, and they return to normal. If is a salivary cyst, what you drain out will literally just be clear saliva. We used needle and syringe. It could be an infection, in which case it will be the pus and blood.
Beth