Hi, Welcome to YT!! The standard for yorkies is 4-7 pounds. How much does Dash weigh right now? Does he need to put weight on? What are you feeding?
My Bubba is 4 1/2 pounds, he eats almost 1/4 cup of Innova every day & a baby carrot or 2 and maybe a small treat. Roxy who is 3 1/4 pounds eats almost as much, but she is a more active dog. They are both 6 yrs old.
Following the directions on your dog food pkg is a good place to start. Then take into consideration what extras you're going to feed each day.
You'll have to sign Dash up for our Little Gentleman's Club, you can do so on this thread:
http://www.yorkietalk.com/forums/gen...come-join.html