most poisons that kill rats will also kill anything that eats the bodies. There are poisons that don't , but not sure how effective at killing rats they are ?? If you want to be sure you won't kill either your dogs , cats or even wild animals that eat rats , then the only way would be to stick with cats ,dogs ,traps and an air rifle ....I HATE RATS...yuk ....they make me shudder.
cheers
Russ