Legal Question in Civil Litigation in California

I'm sorry to hear about your loss. I know how painful it can be to lose a pet.

Sure you can sue, and you can seek damages for your emotional distress and the value of the dog as well as the medical bills.

Whether you should win such a suit will depend on several factors. Who owned the fence? Was it maintained reasonably well? If not, was the failure to maintain it a factor when the dog broke through? I would also want to know more details about their fight. Even if the other dog's owner doesn't bear *all* of the blame, she probably bears a substantial portion of it. If she does, she can be held liable for the same portion of your loss. If other people bear part of the blame (for example, if the fence belongs to your landlord and he failed to maintain it), they may also be liable.