| Interesting question. One of the reasons our 4 legged friends (cats, dogs, deer, etc.) don't seem to be bothered is that they have fur coats. It's not likely that the urushiol oil gets to the skin so they have a built in protectant. I have read that urushiol oil is a secondary chemical and that it is probably there as a means to protect the plant from bugs and animals. As we all know, it doesn't seem to work. Raccoons, deer, birds, and more all love parts of the poison ivy plant from the drupes to the leaves.
I don't have the reference with me now (sorry I forgot to bookmark...) but will look it up. The paper did a nice description of some of the theories as to why these plants have this secondary chemical. And there are other plants which are skin irritants which do not have urushiol oil. Seems we (humans) are plagued with ills from a variety of sources :-/ |
