Benefits of Spaying and Neutering
Sterilization saves lives since overpopulation is the single greatest killer of dogs and cats in the U.S. For every human birth, 15 dogs and 45 cats are also born. About 8 million animals are killed in our shelters every year, primarily because there is no one willing or able to care for them.
Roaming fertile female cats suffer from being reproduction machines. A female cat can be nursing one litter while pregnant for the next. One unspayed female cat, her mate and their offspring, reproducing at a rate of two litters per year, will result in 11,800 felines in just five years.
Spaying, by removing the ovaries and uterus of females, eliminates the possibility of ovarian and uterine cancer. Also eliminated is bacterial infection of the uterus (pyometra), commonly afflicting older unspayed animals and requiring emergency surgery to save the animal's life.
Spaying can also prevent mammary gland tumors, common in unspayed dogs and cats, found to be nearly 50% malignant in dogs and nearly 90% in cats.
Spayed animals are not exposed to the dangers of giving birth. Giving birth becomes perilous in some animals with an overly narrow birth canal. Inadequate body size can make a normal delivery difficult, sometimes necessitating a Caesarean section.
Unspayed cats can experience the stress of heat cycles during 10 months of the year. In heat, many yowl or writhe and often attempt to escape the house.
Spaying also prevents the irritability and aggressiveness that some dogs show while in heat or nursing. Neutering prevents the same traits in male dogs while in pursuit of females.
Neutering, by removing the testicles, not only prevents testicular tumors (the second most common tumor in dogs), but is the only effective treatment for them.
Enlargement of the prostate gland, affecting over 60% of unneutered male dogs older than five years, predisposes the dog to prostate and urinary-tract infection. Because enlargement is caused by the male hormone testosterone produced by the testicles, neutering acts as both prevention and cure.
By eliminating the sexual drive that can cause dogs and cats to bolt from the house or yard, neutering helps protect them from injuries and diseases associated with roaming. Neutering decreases roaming, one study found, in 90% of male dogs. An urge to mate greatly increases the chances of a male cat slipping out the house and possibly incurring fight wounds and injury.
In many male dogs, neutering reduces or eliminates sexual mounting behavior and territorial urine marking inside and outside the house.
Most fertile male cats spray (urinate) on furniture and walls to mark territory. In contrast, only one in 10 neutered males spray.