Big cat versus horse

What is the smallest big cat that could reliably take down a horse? Assume a medium size horse, not a Clydesdale or one of those tiny ones. The kitty can be as hungry and motivated as need be. Thanks in advance.


Although the cougar does not usually prey on horses, they have been known to ambush and kill horses on occasion. A healthy cougar won’t normally go up against a horse, but if one is starving and desperate enough, it’ll make the attempt.