about 10 years ago i had a little whippet x collie, when she was 3 years old she got a bit sharp, one night she jumped a 5'4" fence grabbed hold of a passing women through the railings one snap and the poor women had a black bruise as big as an apple with 4 red score marks off the fangs, i said i would put the dog down but fair play to the women she said no and did not kick up a fuss, needless to say me and the dog went for the long walk the next day , the way i looked at it could have been a child, you have to get your priorties right even if it hurts