This is the chemical in 99% rodent bait sold where I live, and apparently the worst for causing secondary poisoning...
https://en.m.wikipedia.org/wiki/Brodifacoum
What I find strange, is, at least where I live, there is all this rqt bait for sale, most far more toxic than needed to get rid of the rats, and none of the places thqt sell it offer vitamin K. You can get it from a health store but i had to ring around.
I wonder why places that sell it dont also sell a vitamin K treatment.  I know from when I worked at the vet clinic that time is of the essence if a pet consumes poison, so surely if people had vit K on hand, whether its primary or secondary consumption, they could treat their pet as soon as they suspected, rther than delaying till they get to a vet, or because of the cost delaying till their pet has symptoms (prob too late then)
I wonder...why dont the rat bait companies sell the bait with a vit K antidote so any pet owner who suspects poisoning can give that straight away.