The biggest advantage of spaying a female is no unwanted pregnancies and neither do you need to keep your dog shut away when she comes into season. Some females, following a season, develop a pseudo-pregnancy where they think they are pregnant. Spaying prevents this happening.
Females spayed before their first season reduce the risk of developing mammary cancer. The risks following each subsequent season increase as the majority of mammary cancers are under hormonal control. A large percentage of mammary cancers are malignant so can be fatal if action is not taken immediately.
Entire females can also develop a condition called Pyometra when the womb fills with infection. This normally occurs after a season. The dog will be lethargic, is often sick and will drink more than usual. As antibiotics will not treat this infection an emergency spay has to be performed. This is a higher risk than a normal spay as the female is already poorly.
With both male and females, you need to watch your pet’s weight post-neutering and your vet will be able to advise you on a suitable diet and exercise.