I'm so sorry

As far as Luka's not wanting to let go thing, it could be that she was raised with wolves but some dogs are just like that. Winston is the same way (most Dobes bite and release, he holds on forever) and he was raised with one other dog...but maybe his way of fighting occured when he was wandering and having to fight other dogs for food. I hope everything get's resolved again soon, having to deal with dog fights certainly is not fun at all..