Health Benefits of Spaying and Neutering:

Female Dogs
Spaying removes the ovaries and uterus, eliminating the possibilities of ovarian and uterine infection or cancer. Bacterial infection of the uterus (pyometra) commonly afflicts older un-spayed cats and dogs. In its advanced stages, pyometra causes general illness and kidney failure. If the uterus ruptures the animal will probably die. Pyometra requires emergency spaying, which may not save the animal. The best preventive care is to spay dogs and cats when they are young and healthy.

Spaying can also prevent mammary gland tumors, the most common tumor in un-spayed female dogs and the third most common tumor in cats. They are more common in dogs than in humans. A high percentage of mammary tumors are cancerous: in dogs, nearly 50%; in cats, nearly 90%. Once a cancerous mammary tumor spreads to the bones or lungs, the cancer will be fatal. An un-spayed dog is 200 times more likely to develop mammary tumors than a dog spayed before her first heat. An un-spayed cat is 7 times more likely than a spayed cat to develop mammary tumors.

Spayed dogs and cats also avoid the dangers of giving birth. A narrow birth canal or inadequate body size can sometimes make giving birth perilous.

Male Dogs
Neutering removes the testicles, which prevents testicular tumors and greatly reduces the risk of developing rectal tumors. A dog who develops a testicular tumor must be treated before the tumor spreads — the only effective means is neutering. Testicular tumors are especially prevalent in older dogs and are the second most common tumor in male dogs.

Enlargement of the prostate gland affects over 60% of unneutered male dogs older than five years. Prostatic enlargement predisposes a dog to prostate and urinary-tract infections, which can make urinating difficult and painful. If an infection leads to an abscess, the abscess must be surgically drained. Common consequences of the surgery include system wide infection and shock or sometimes death. Because prostatic enlargement is caused by the male hormone testosterone, and testosterone is produced by the testicles. Neutering acts as both a preventative measure and a cure.

Additionally, by eliminating the sexual drive that can cause a dog to bolt from the yard or house, neutering helps protect dogs from injuries associated with roaming, such as being hit by a car or infections transmitted by other animals.

Behavioral Benefits:
Spaying prevents irritability and aggressiveness that some dogs show while in heat. For indoor dogs, this also prevents vaginal blood spots from getting on household furniture or the carpet.

In many male dogs, neutering reduces or eliminates sexual mounting behavior and territorial marking with their urine (including any that might take place in the house.


Q. Is spay/neuter surgery painful or dangerous?

A. During spaying/neutering, dogs and cats are fully anesthetized, so they feel no pain. After surgery they may experience some discomfort, but this disappears in a few days or hours. As with any surgery complications are possible, but rare.

Q. Is spay/neuter surgery expensive?

A. Spay/neuter surgery generally is less costly than most other major surgeries and some local veterinarians provide discounted spay/neuter to the public. It is less expensive to spay an animal than to pay for the costs of caring for an entire litter of puppies or kittens. The Orange County SPCA offers vouchers that cover the cost of an uncomplicated spay/neuter. Apply for one HERE.

Q. Should a female dog or cat have one litter, or at least one heat, before being spayed?

A. A dog or cat has the best chance of good health if spayed before her first heat. Early spaying also reduces the chance that the animal will “accidentally” become pregnant. But, we do not recommend spaying before four months of age.

Q. Can a pregnant animal be safely spayed?

A. Many animals and cats are spayed while pregnant to prevent the birth of puppies or kittens. However, a veterinarian should be consulted about the health and stage of pregnancy before making such a decision.

Q. Do spayed/neutered animals become overweight and less affectionate?

A. In some dogs and cats appetite will increase, but if your pet is given the proper amount of food and exercise, they are unlikely to become overweight. Additionally, dogs and cats tend to be calmer, more content, and more affectionate after spaying/neutering.

Q. Why should a male dog or cat be neutered – they don’t give birth to puppies or kittens?

A. Besides the health benefits received from neutering, a male dog or cat can impregnate many females in a short period of time, and often without the owner’s knowledge. This greatly contributes to pet over-population.


Reference: Foundation for the Care of Indigent Animals, http://www.fcianimals.org/education.html