Hmm....I've had a look at this site, but unless I actually join I can't see anything about this. And as I'm not in the US, I'm not about to join.
However, it does seem a bit similar to LETS to me, only with physical goods instead of services. I can't actually see how offering a pet or animal up for a new home when it's needed, is bad. Surely better than abandoning it by the road??