If the dog is 'vicious', your friend should probably be going to a 'doggy school'. They work very well, especially if your dog isn't very good with other people/animals. Puppy school also really helps (and because I think it's a puppy (unless she has two dogs)) the dog probably isn't really vicious. Puppies just like to nip and eat almost everything. Puppy school is good for socializing dogs and having them learn the basics (and the dogs can learn more too, if they go back). A 'puppy school' is usually a class once a week that the owner and dog to go together and learn how to train/discipline dogs.
And they offer most of these classes at community centers for pretty cheap too. If you're having serious problems with the dog, it's always best to get a professional's help.