[kjc]

Oh, I agree, muzzles don't make dogs angry, but this is a young puppy that has experienced being rolled and held down numerous times. Muzzles are a form of control, and this pup needs to learn that control can be achieved without it being forced on her.

To develop trust, it will happen quicker without the muzzle. I am also worried that the OP may get bit trying to put a muzzle on this pup.

It won't take too long hopefully to turn this pup's behavior around, but I honestly think a muzzle may do more harm than good, considering what the pup has been through. I'd even go to every two weeks for baths (for a month or two), and with regards to grooming there is nothing that needs to be done that couldn't be let go for a month, including her nails. A gentle brushing with minimal restraint would do it.

It is not normal for a 4 month old puppy to be vicious either. Something caused her to become that way, and I (IMVHO) would proceed with great caution handling this pup so as not to inflict further injury to her mind. She is still young enough that her behavior can be reversed.