Where did you purchase your Labs? If you purchased from a good breeder, chances are, they're purebreds.

Both my boys are shelties but they're completely different. Actually, I can't say I'm 100% certain Kaedyn is a purebred as he's a rescue and we don't have info on his past but judging from his personality and physical appearance, I'm pretty sure he's purebred. My other one, Kai, is also purebred. This one I'm certain about as we visited his father, mother and littermates when we went to visit the breeder. Both are shelties but both look different. It just depends on the genes passed on to the offspring.