I looked up to this crunching sound and saw Kairo chewing on her nails. I do not lie when I say this dog is a chewing fanatic.

I worry as Kairo has actually bitten through her own leg clean to the bone (another reason I worry about her with Anya). I thought she just didn't have bite inhibition period, but she doesn't so much as leave a mark on Ember when they play - and they are both all mouth.

Anyway, I diverted her with an antler, for now. Any ideas on what may cause the nail biting? I'm assuming I should stop it somehow.

I have never seen Zhukov do this, however, Colby chews on his feet all the time. The vet told me that this is a nervous condition, which is weird, because Colby does not appear to be a nervous dog.

I haven't seen this as a nervous 'habit' but I have seen my dogs nibbling on their feet when they've gotten something ( sand / pebbles / twigs ) in between the pads of their feet.

Well it could be what Mark and Al said, Miya kinda does it in a fastidious way, she has OCD or something, and just gets all into her cleaning and I tell her enough and then she stops, but 0 damage to herself. Sofie I think would harm herself if I didn't tell her the same, but with Sofie it's 2 different issues, her nails grow super fast, and if they are not trimmed fast enough for her she goes munching, her other issue and is I guess quite common for dogs with allergies, is when she in fact has too much chicken, that is my first sign she has had too much, she nibbles at her nails, I back off and stop chicken for a few days she stops nibbling. Does she have any allergies that you may know of?

Interesting! She does have seasonal allergies but they seem to have abated majorly after her grooming session. I'm trying to remember if she had more chicken than usual - I did give her a good amount for training, but I can't remember if it was before or after this.

She does have nervous habits though.

And she bit through the handle of the jolly ball I gave her yesterday in under 5 minutes.