[lil louis]

I just have a question. The person who I got Louis from, sold Louis' mom for $1200.00 with full breeding rights to the new owner. I understand that sometimes breeders have to sell their adult dogs, but why would they sell them and then continue to let someone else breed them. I am by no means a breeder, so I was just wondering if this is something that breeders do. It seems to me she should of had her spayed and then sold her.