Reply #2: So sorry, how horrible -

[haele]

If you can look around surreptitiously and see if there's any food or kibble outside in the neighborhood that they could have gotten into, that would be a good indication of were the poison is coming from.

It actually sounds like rat poison (usually strychnine) or drain cleaner. Shari had nibbled on a dead rat and had frothy convulsions for a couple hours, but recovered - she immediately threw up outside a couple times after she got at the rat, but still got enough in her system that we had to get her treated.
Since the kitties systems are so delicate, any little bit of poison is devastating.
I'm so, so sorry you had to go through that with your babies. People who hate enough to poison other people's pets have no idea what it's like.

Haele