The Shih-Poo is not a purebred dog. It is a cross between the Shih-Tzu and the Poodle. The best way to determine the temperament of a mixed breed is to look up all breeds in the cross and know you can get any combination of any of the characteristics found in either breed. Not all of these designer hybrid dogs being bred are 50% purebred to 50% purebred. It is very common for breeders to breed multi-generation crosses.
"This is Chase. He is almost 1 ? years old in this picture, and a mix between and Poodle and Shih-tzu. He is very ornery, and beats up on his brother Storm (a 2 ? year old Weimaraner) constantly. He is very friendly, and thinks he’s as big as Storm (his brother)."
ACHC, DDKC, DRA, IDCR, DBR