In my experience, little boys tend to fill out later. They get their hormones in and their little chests expand. I think if you fix them too early they get a hormone surge and grow more, all my dogs that got fixed early ( 6 mos.) got big and the others that I waited until they were older, stayed smaller! I love all my teapots and tinies the same!! The teapots just don't get to ride in a carrier!!
