We have a 16 week old Shih Tzu. When people ask how old he is they always say "Wow, is that all?". I was just wondering how old yours is and what he/she weighs? He was weighed last Sunday at Just For Pets (similar to Pets At Home) and he weighed 5.7kg which is about 12.5lbs. Both of his parents were quite small. We had a shih tzu who was very much on the larger side in the past.