Strange question. If I have a female and male dog that are mommy and son would the boy try to mate with his mother? I didn't plan on getting her fixed and she accidentally got pregnant when we moved in with my parents. A boy dog got ahold of her. Anyway I can not under any circumstances get her fixed right now. I just can flat out not afford it. A lot of things have happened and we are struggling financially. Anyway the boy puppy is about 4 months old. Is he to young to mate and would he even try with his mother? Just wondering because she is in heat and I would separate them. She is under strict watch right now while she is in heat to prevent any more puppies. She is to small and I'm scared it would hurt her. Plus I just don't like the idea of her being a puppy factory