For a 3-4 lb chihuahua, I used not very much yarn (less than I would for an adult hat, probably on the scale of toddler/child hat).

The measurements for the dog are as follows: Neck size is-6in. Waist is - 8 in and length from collar to waist is - 5 inches. I measured a little big for neck and waist to give her some wiggle room.

Knitter will need to scale pattern according to her dog’s size/preferences.