no I don't think you need to take care of half the medical bills. maybe a smaller contribution for good will and karma but as it stands it was in no way your fault. My dog ( black lab) attacked and killed another dog( husky) when it came into our back yard. Earlier on that same husky had EATEN my pet rabbit out of her hutch in my backyard and it had come back for seconds i guess. My dog loved my rabbit and knew that husky had killed her. it was before school and I was eating a pop tart when I heard my dog growling at the door. This was normal because of the many squirrels we have so I let her out not thinking that the huskie was in my back yard again. well as you can probably guess I saw white fur flying and I ran outside just in time to see the husky running, covered in blood, with my dog at his heals. She chased him out of sight of my street and I was calling to her. She was soon galloping back with blood all over her ( his blood she suffered nothing) I put her inside and was secretly happy that my doggie had gotten revenge for my Rabbits death. but when the bus came and we were driving to school, as we turned on the main street I saw the husky lying in the gutter.. My dog had chased him to a busy street and he had gotten hit. of course I felt aweful and being only 13 I felt a tad responsible, but that dog was always getting away from his owners and he was not friendly as he had even attacked some children. the owners kid came to me and said I had stolen their dog and it was all my fault. I was 13 and I was not about to get into the middle of a dog fight before school. I felt bad for them but I felt in my heart that it was karma. That dog took my beloved rabbit away and my dog returned the favor. The people called the police but we were never charged. It was their fault their dog got out and into my yard. My dog was just protecting my house. So I kinda understand what your going through. I miss my rabbit... she was pregnant when she died...