Yesterday!lol!! Just kidding; but I had sawyer neutered at 4 months, and he is fine. Sometimes breeders even neuter them before they send them home. The earlier you stop him from marking, the better it will be for you and him. if you do not intend to breed, there is no logical reason that I know of to have an unneutered male. It prevents running after females in heat, lowers aggression against other males, prevents testicular cancer, and as mentioned helps to stop or at least lower the urge to mark. They do not automatically get fat, and it is one of the best things you can do for your pet. Good luck.
