Mine has done this too .... she used too when getting brushed also .... out of the sweetest Darling ever became the Devil in Person .... I cut her hair short ... and that took care of that ..... with the bath .... put some toys in it and have him or her play for a few min in the warm water ..... seems to work with mine ..... and she gets Treats afterwards .....
Don't give up ..... Good Luck ....