We've had a visit from a neighbour saying that he recognized our cat and he attacked his cat, causing an injury that needs vet's attention. This has apparently happened before, too. He says his cat is too scared to go outside now and he wants us to help out with the vet's bill.
First, is it reasonable for us to do this? We didn't after all take his cat to the vet. Second, if it is our cat doing this, he is probably trying to 'play' and he is rather rambunctious while play fighting - we have seen him being that way with another of our cats, although certainly not causing any kind of serious injury. What can we do, exactly? We'd rather not lock him inside (it's a bit difficult anyway because we have 3 other cats that we don't want to lock inside and the catflap only has a "open on chip" mechanism for entry, not exit). It's quite a difficult situation, one that I've not been in before, and I'm not sure how to act.