Female
Neutering will decrease the risk of developing mammary and ovarian tumours later in life, and will decrease the risk of developing infections of the womb, some of which could be fatal.

Male
Neutering will reduce testicular tumours, and decrease the male’s tendency to wander in search of a female in heat and will be less likely to have encounters with cars, dogs, wildlife, or to get into cat fights.....thereby preventing wounds and abscesses.

Neutering will decrease the risk in both sexes of becoming infected with feline aids, feline leukemia, and other serious infectious feline diseases.