Oh poor cat, and poor you, having that bill. I agree with Little Blue, its unlikely they will admit anything, and definitely will not want to pay.
Our neighbours large GSD keeps chasing the cat living opposite. Its ancient, probably late teens. I was minding it when the owner was away, and saw the dog chase it yet again. It tried to run under the gate, and injured its back and legs. I had to take it to the vet for treatment, and a year later, it walks in a strange fashion.