Hello,
My Daughter has a 5 month old Chihuahua ( Buddy ) We have notice
That He won't Bark ! He will wimper /whine and very little at that. He's
in good health ! cutest little thing ever. My daughter has another Chihuahua
name Rudy ! even when he barks buddy's just sits their. Is buddy still to young ? Will he just start barking soon ? any information would be so kind !
my Granddogs, olgaflowers

A friend of mine had two chihuahuas with a similar age difference...the older one almost never barked, and the younger one yaps constantly. I think it might be a personality / genetic thing!

Hi,
Puppy's like human babies have to learn to talk. Chihuahua's are well know for their noisy behaviors. Also, remember that your other dog is the alpha dog of the house and the puppy will learn from it.

Enjoy the quiet while you can

PS: If you don't start hearing from the puppy soon, you might want to take it to the vet for a check up.