I've always wondered if there are any differences between a single litter pup and those of multiples. My Yorkie Heidi (now 2 yrs old) is a single litter pup. She is very smart and strong willed where the previous yorkie I had for many years was layed back & happy-go-lucky kind of personality. I didn't know if maybe there can be a difference being a single birth, or just her particular personality. |