My friend was recently bitten by her oldest dog (she has 2). She said that before she went to bed she leaned down to give her dog a kiss goodnight when all of a sudden she got really mean and bit her. Well, she bit her so hard that her tooth went right through my friend's lip. My friend got scared and pulled away, when she did that, the dog's tooth ripped out of her lip and she had to go to the hospital and get 15 stitches in the inside and all the way around to the outside of her lip.
They took the dog to the local ASPCA where they are going to hold the dog for 10 days to make sure all of her shots are up to date and then the dog will be put to sleep.
The family can't figure out why their dog bit my friend, but she said that ever since they got their 2nd dog the first one got really mean and jealous of everything.