Well, it says on the label that it takes size 1-3 needles.
I've used this yarn with size one needles a couple times now, and I like it. But my gauge is about 9-10 stitches to the inch on size ones, so I must be a tight knitter. I have noticed that the yarn does get fuzzy on the bottom, but I haven't worried to much about that. It's the part of the sock that gets the most wear anyway, and I just figured that was part of hand knit socks.
Your socks are very pretty, by the way, as is your little dog!