Well there would be some circumstances that that wouldn't be quite fair. Like if the dog bit the owner, or something. But that I think would certaintly be better than murdering the dog and just letting the owner get scot free. The dog is less at fault then the owner in almost all cases.
Though it would suck for these people, since their kid just died, then get thrown in jail for it... though it is their fault when you come down to it.