On two occasions my boyfriends sisters dog has broken out of the backyard and attacked my cat at the front of their house, while i was letting her get some fresh air(she lives inside at all times). Both times have been extreme near misses and i'm terrified the next time my cat wont be so lucky. Ive asked my boyfriends sister to board up her dogs escape routes but she wont listen to me or discipline her dog for trying to get out. If this happens again and causes my cat injury can i sue her for vet bills? Thanks for your time.