I just read a great article in a vet-tech journal (i.e. a Reliable Resource) which said that neither poinsettias, holly nor misletoe are poisonous enough to hurt anybody or anything. At worst, a serious poinsettia binge could cause a tummy-ache and teach pooch not to munch on houseplants. So, the lady who had a cat get sick on it - that cat must have been especially sensitive, as that is not a typical reaction. Personally, I'm hoping that one of these years my cats will sample the poinsettia and get sick, and thus decide to leave all my herbs alone... Phlox, lily of the valley and digitalis are more deadly than christmas plants, and my pets don't touch those.
Chocolate on the other hand is truely deadly to dogs - the chemical is called theobromide, and it doesn't take much. Chocolate-hull mulch will kill, too.
Now, never having had a counter-surfing dog before my current fuzzy-butted moocher, Cooper, I'm beginning to suspect that any plant or food eaten by a pet has a potential to be deadly. At least, if Cooper opens the cabinet and rips up another box of cereal, I just might kill him...
...And, I thought that belly buttons were only holding tanks for lint, until it could be safely disposed of?
-Tara