We have a Chihuahua that is a Runt and when we got her she was roughly 2.5 lbs. And for the last 4 and 1/2 years she has been 4lbs.
How Big Does A Chihuahua Runt Get?
Every dog is it's own.I have a dog that came from a 3.3 lb chi and she now weighs 10 lbs!(a bit overweight,I admit,but she normally weighed between 7-8 lbs before I got her spayed)