Males and their owners are spared roaming and fighting and the resulting injuries, spread of disease, and expenses. Healthier pets - Neutered males don't have testicular cancer or the prostate problems common in intact dogs. They have no risk of uterine infection, or the many complications associated with pregnancy, whelping, or raising a litter. Our mortality rate is lower. I've performed over 2,500 procedures with only one loss.
Complications occur less often.
Most compelling, in a study done by veterinary students, completely inexperienced surgeons, their death and complication rates were lower. It's easier on the pet - anesthesia time is shorter and recovery takes only a few hours. It completely eliminates the possibility of accidental litters. The list is endless. It completely eliminates the possibility of intentional breeding by well meaning but ignorant owners.