At some point I tried to calculate how much seeds would be necessery to actually poison a rabbit, it would be more than it's body weight at once, of course the cyanids would be the lesser problem then compared to the exploded rabbit.
Those compounds are quite widespread in botany, and pretty much every herbivore or omnivore can cope with quite an amount without any issue. Rabbits, being apex predators in that regard, can cope with lots of different stuff, either by avoiding it (if they had the chance to learn to follow their instincts) or by just stomaching it.