The primary benefit is not having to worry about reproduction, over population and unwanted sexual behaviors. Spaying and neutering your pet is also very beneficial to their health. It will drastically reduce their chances of developing health problems including; mammary cancer in females, pyometra (a life-threatening infection of the uterus that generally occurs in middle-aged to older female dogs in the six weeks following heat), prostate enlargement or cancer in male dogs, prevention of certain types of hernias and tumors of the testicles and anus in male dogs, and many more.