It if helps Sophie Kate is at 8 lbs full grown and she wears a small in the Puppia. We have had one of her harnesses since she was 7 months old and was about 4 lbs, it was big on her but she still wore it (she had to since she decided to chew the one harness that fit her properly).
Depending on her head and chest size you might be able to get a small and make adjustments. Remember with a Puppia you can only adjust the chest.
I remember trying to buy my first harness, I was so frustrated because I kept buying the wrong sizes.
Also Amazon has great prices for Puppia products.
__________________ Cheryl,Mom to  SophieKate |