I'm not exactly sure what happened to her so we'll have to watch nxt season to find out buut i think that lydia&the vet r some how connected..i think that both of them are the same thing but i just don't kno what they r.
I know when we saw it, we were like "omg is she Teen Wolf's Sookie? She MUST be a fey!" But really, I think if she were a were-creature like someone else suggested, she would have healed quickly... She must be some other supernatural based creature, regardless of what was said by the writers