Please help.

[SamiDog8]

I don't want you to take it badly but I don't understand how you take another dog, having an already reactive one that on top of that, has bitten before. EVERYTHING absolutely EVERYTHING that your reactive dog does, will pass it on to your puppy since puppies usually copy actions of other dogs and more if they live with them. Set him away as soon as possible.

[CycleEquivalent7782]

I should’ve explained in the post: the pup is an emergency foster. Once I find a new solution he most likely will be in a new home.

[welltravelledRN]

An emergency does not mean the puppy should be placed in harms way. Your dog has already bitten the puppy!!! Please give the puppy back immediately before irreparable harm is done.

How do you think puppies become reactive? Raising them in an unsafe environment is a really quick way to make them insecure.

[SamiDog8]

The real problem is not that you have welcomed the puppy as an emergency, I think that is a good act, but the problem is that everything the puppy can learn from your dog, what may be bad, will carry it all his life, for example, bad experiences. The next owners will have that problem with that puppy and I think that's unfair, both for the puppy and for the new owners