I have chosen to leave all of my dogs intact. I have had 3 males and they all have kept their parts. I think that the risk of getting the cancer in the man parts is so small it isn't worth it. I have seen many dogs gain tooo much weight from being fixed, and I cannot deprive my dogs of food just to keep them not fat. I would have gotten them fixed-maybe, but Jay is very against it, and I will not go behind his back and do it, it isn't that important to me.
I have read in many places that you should at least wait until they are a year old, but that if possible you should wait until atleast 2 so they fully develope, which requires hormones they get from all their parts, missing part=missing something else somewhere, which could just be growth....who knows.