New dog really defensive over treats?

Wow are you NUTS? That Pit Bull is going to KILL that little dog.

Lack of proper training is the cause for many things. You need to learn how to correct this. Doing research & learning more about dogs & their behavior will give you more understanding why dogs do certain things. Too many people apply human attributes to dogs & that is wrong. You are working with a dog, learn more about the species.

The new dog has a stronger temperament than the house dog & the new dog will be the most dominate of the two. Stop new dog from TAKING the treat from the house dog. Just stop it, don't allow it, correct the new dog, hold the new dog until the house dog eats the treat. Separate them when you hand out treats.

Training is everything. Since new dog has such a strong temperament, watch to see that new dog doesn't dominate the the house dog, sounds like house dog is timid/laid back/submissive to the new dog & it may take some time for house dog to stand up for himself. By all rights the house dog should tie into new dog for being over bearing but due to temperament he doesn't.

The new dog has the more dominant nature and is the boss dog now,and in her eyes all treats and toys are HERS, not his.

Be careful the new dog does not nick the small dogs dinner if they are fed together.

Don`t give the dogs treats and then leave them to eat it whilst together.

Treats should be earned anyway and not dished out willy-nilly for nothing.

Make each dog sit or lay down etc, before they receive any treats.

You only got the new dog yesterday and it can take some time before you know all her "quirks" and how she behaves in all situations.

Once you get to know her properly you can adjust the way you go about things that are best for both dogs.

Your smaller dog "may" get wise to her tactics eventually, and rush off and hide somewhere where she can`t get him, when he is given any treats.

But do make both dogs earn their treats and they will respect YOU more for doing so.

Treats lose their value as a treat if given out freely.

Then correct this behavior and don't allow it to continue, which is your responsibility, not the dogs. You're responsibility to keep them both safe from harm by whatever means necessary, if that means secure containment/separation so be it.

Train him. Maybe put him in a room by himself every time he does that. It will build a negative connection between the two. Though take my advice with a grain of salt. I have it easy with my standard poodle, who practically never misbehaves.