Never go by what someone tells you is "expected". the best trick I've learned is go by their size at 12 weeks, and DOUBLE. Derby turned out to be exactly that, and we were told he'd be 7 pounds~ "at the higher end of Yorkies" (like what my husband wanted) and low and behold he's a 12 pounder!
Now your pup is already over that, but not by much! It may only be a bit bigger! Derby hasn't gained any weight since he was 6 months old, although he filled out more and gained 1-2 pounds after neutering.
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