Good morning! I'm coming here because we are out of solutions locally. We have been working with a trainer to socialize and soon start officially training our GP puppy. However, we have had no luck teaching her not to bite. She is literally out of control with biting. We have tried:

- teaching her bite inhibition with a treat (holding a piece of her food in our thumb and forefinger while she licks, closing our fist when she uses teeth, opening again when she licks and rewarding) (this doesn't work after a couple, she starts biting hard and all the way up your arm if you don't open your hand)
- yelping when she bites (she literally ignores this and keeps going)
- a firm "no" when she bites (she literally ignores this and keeps going)
- growling when she bites (she literally ignores this and keeps going)
- ignoring her when she bites (she doesn't care one bit about our attention and keeps going)
- a tap to the nose when she bites (bites back hard after)
- curling her lip under so she bites her own lip instead (doesn't deter her, she keeps biting)

nothing so far has worked! She only gets more upset and bites more and harder. She flails around while making an aggressive noise (not a growl, a different type of noise) and tried to bite anything in sight. She gets very angry and bites very hard. We are at our wits end. I know this can be a stubborn breed and have worked with stubborn breeds before, but this behavior is all new to me. I want to work on correcting it before it gets even further, especially since I'm worried it's gone too far already.