A lot of health risks are involved for not neutering and spaying dogs and cats actually. They can get cancer from not getting fixed, running away is more of a risk, behavior problems, they tend to live longer when they are fixed. Lots of benefits to fixing animals. You would want to talk to your vet to see if fixing him at this age is a good idea. Also when dogs aren’t fixed, all they think about is mating. So if they aren’t mating it can be very frustrating for him.