introducing a rescued chihuahua

I have a 2yo Boxer, Rocky, a 3 yo tux named Andrew, and a kitty tabby named Dopey. The problem I have is a 4 yo slightly timid--long haired chihuahua  named Roxie came to us last night. She has been neglected because owner couldn't afford to take care of her, She was shy at first, but has settled in with each of my sons, 12 and 17, in her own way. I finally got her to eat some eggs and turkey, but I have to  get some dry food soon.   That's my intro. My question is.. Andrew is a hunter. He keeps the field mice, rats, snakes, armadillos and possum away from our home (yes, we live in the country). He saw her and got into pounce position, so Dopey did the same. Will I be able to teach Andrew who comes in the house from time to time the difference between rodents and a chihuahua? My boxer, Rocky is just a big baby and nosy. Not worried about him hurting Roxie. But he does have a problem with the cats around her. I know I am rambling, need advice--or at least suggestions. All my animals are rescue except Andrew who was born here--Mama Boo was a rescue. 

I am not an expert on dogs, but this article might help -

Introducing Cats to Dogs

I think the important thing with any form of pet introductions is to do them very gradually and have lots of patience. Let us know how it's going!