One more note...you cannot go by the weight of your pup to the weight that is on the package of baby diapers...it doesn't work. I first bought the newborn baby diapers that stated they go up to a 10 pound baby...so I figured since Bailey and Charlie were four and five pounds the newborn size would work, but it did not because you aren't fitting them on your pup the same way you fit them on a baby. Hope that makes sense
Size 2 is what I found to work with Bailey (5lbs) and Charlie (4lbs)