Hi Tammy - If you are referring to a dog continuing to breed the same female during her heat cycle the answer is yes, as long as she will accept it. Dogs release their eggs over a period of a few days in the middle of their heat cycle so it is possible for the same male to breed her more than once...it is also possible for other males to breed her during that time. This is one way to have pups that look drastically different from one to another.

Another way to look at this question is whether the male will try to breed other females that he may meet whether they are in heat or not. An un-neutered male will display mating type behavior to most any female and in many cases, he will "mark" his territory, indoors or out, by lifting his leg on things so his scent will tell other males he "owns" the area, the female dog, and in some cases, the humans. He may also show aggression toward other males.

Spaying and/or neutering at a young age are the best answers to the problem. It also helps cut down on prostate cancer and mammary tumors.