Spaying helps prevent uterine infections and breast tumors, which are malignant or cancerous in about 90 percent of cats. Spaying your pet before her first heat offers the best protection from these diseases. Your spayed female pet won't go into heat. While cycles can vary, female felines usually go into heat four to five days every three weeks during the breeding season. In an effort to advertise for mates, they'll yowl and urinate more frequently—sometimes all over the house! Your neutered male may be better behaved. Unneutered cats are more likely to mark their territory by spraying strong-smelling urine all over the house. Your male pet will be less likely to roam away from home. An intact male will do just about anything to find a mate, including finding creative ways to escape from the house. Once he's free to roam, he risks injury in traffic and fights with other male animals. Your neutered male may be better behaved. Unneutered cats are more likely to mark their territory by spraying strong-smelling urine all over the house. Some aggression problems towards other males may be avoided by neutering.