My dog is a Pomeranian & Shih Tzu mix, she has the long hair like a Pomeranian and only weighs about 7 pounds. Her hair grows out very long like a Pomeranian and when it gets long it tends to get into knots no matter what we do, unfortunately this time of year ( December ) for us and her the only way to get the knots out is to take her to the groomer who in turn has to cut her hair very short , which in turn leaves her very vulnerable to the cold, she is an inside dog but still gets cold now and shivers. I am so glad that I found this warm sweater for her, fits very well, I ordered the 12, Now No more shivers. Perfect solution to her being cold. We really love the design, quality and fit. Has the opening for her to relieve herself without having to take it off when we let her outside to go potty and an opening in the top for you to attach your harness through. I probably could of gotten away with one size smaller because this one is a little loose around the upper neck, not saggy though. I think it is more comfortable for her to wear that way. Don't know if it will shrink a little when washed but if it does it should not be an issue in my case. I absolutely recommend this item for your dog to solve their getting cold problems, we were not disappointed one bit. Of course Amazon Prime shipped it to me in a couple of days without any delays.Update, just washed this for the 1st time, no shrinkage at all.