I don't. But that Webmd article has a list - it could be something like anemia. She's a young girl right?
Do you have ticks there?
ETA - also be thinking food toxins like a recent ingestion of onion or garlic or food that had that in it + regular toxins that we think of as poisons + medications (hers or yours), supplements (including natural things)
Good list: http://www.aspca.org/pet-care/animal...on-control-faq
I'd maybe even want a urinalysis with that full blood panel - just to check.
Hopefully it's just a good to be cautious kind of thing.