First of all there is no such thing as 'vicious' growling. Growling is a way a dog has of communicating. It is a way of avoiding conflict/aggression. A dog who growls is not going to nessisarily escalate to biting. The more a dog growls, but never bites the more self control it shows, and the more information it gives those around them about their state of mind (this is a good thing)
You do not want to so much as stop the growling as you need to resolve the underlying issues that are iliciting the growling. (never get mad at your dog for growling, you may teach the dog not to growl, but then when upset, she will be likely to bite without warning)
So more info needed. How old is the dog, and how long have you had her, how was she socalized when young. Does she growl at all dogs, all people?