No it's not, it's the dog owners fault for not breaking the dog to cats. Any dog that chases cats is an accident waiting to happen. There are endless possibilities of what could happen, even ending up with lost human life if the cat runs out on a road with the dog chasing it. There is nothing macho about killing cats with dogs.
If you can't break a dog to cats I would seriously suggest you don't have one.
TC
ime always right when ime in the wrong,lol