"Step moms" dog bit my kid.

The father[M29] of my children has been dating this girl[F31] for a couple years. She has a large dog, who I always thought was alright with kids, but tonight my daughter [5.5yrs] came home with a pretty good purple/red scratch on her face. I asked her what happened and she told me she was looking in dogs eyes to see the color, and he growled and bit her. I have 2 large dogs in my home; husky and German shepherd. My children have been taught since day one to be "easy with doggie", and that dogs and animals are not toys. My daughter especially is very attentive and kind, so I truly believe she was not pulling or grabbing the dogs face in any harmful way. I also want to add I've dropped the kids off and picked them up several times, and this dog is very territorial, barks and growls loudly when someone opens the gate to the yard.I'm wondering what I should do about this. I asked their dad what happened and he said the dog did bite her in the face and hes "currently dealing with it". I should also add, he dropped the kids off here at home at bedtime, and didnt mention this incident. I'm still kind of in shock and I dont know what I should do. I took a photo of her face and kept the screen shot of him telling me the dog did bite her. Has anyone been in a situation like this before?? Any advice?Edit to add: Having conversation with their father it sounds (vaguely) like this has happened to others before. He has been acting out, pooping in the house, growling everytime someone comes in the door. I'm definitely reporting this. I understand and will definitely teach my kiddos about eye level with dogs, that's good info! But on the same page, this 5 year old dog living part time with children cannot be doing this. via /r/Parenting https://ift.tt/2TFY01I