I'm in the pest control business and suppliers make anticoagulant rodenticide that will not transfer from rat to predator.
In Florida Birds of prey were being killed in vast numbers when anticoagulant rodenticide was first used....oops! because eagles, falcons, and such were catching rodents and eating them...
Science fixed the problem...
Rats just like bacteria become resistant to poisons eventually. The only solution long term is to cut off the food supply by properly disposing of garbage.IE stop living like slobs