Plants that are poison

I have read that Philadendrons (sp?) are poisioneous to animals. My cats constantly play and chew them. Why aren't they affected?

That is a good question, I'd remove them even if nothing seems visibly wrong - and ask your vet if you should have their kidney values checked or not. The quick surf I did said that in cats it causes weakness, listlessness and loss of kidney function. (and mentioned what it can do to toddlers who chew on the leaves...ouch.)

I tend to be assume the worst is possible, not the approach that everyone else takes, I know