Hi Guest
Why don't you
register as I am sure your question is going to require a question and answer session to find out more.
In the meantime if you think the growling is at all aggressive rather than an invitation to play (body language should tell you this) then keep them separate until you have sorted it to cut down on potential vet bills.
How long has the growling been going on, are any of the others (or humans) present when it happens, do you know what sets it off?
Christine