1) Spaying or neutering is fool proof birth control that lasts a lifetime.

2) Spaying or neutering provides relief from such hormone driven urges as:
Aggression toward other dogs, particularly for males.
Territorialism, that is, the tendency to be overprotective of the dog's home ground.
Wanderlust, that is, the desire to escape from the yard and seek sexual adventure inthe outside world.
Dominance.
Marking territory with urine/feces.
Unwanted sexual behavior such as riding, sniffing, licking, arousal.
Frustration which occurs when the behaviors dictated by hormonal urges cause the dog to behave in a way that is undesirable to the owners.

3) Protection (either partial or complete) from such hormone-induced conditions as:

MALES
Testicular cancer
Benighn prostatic hyperplasia
Acute and chronic prostatis, prostatic abscess
Perianal gland adenomas
Orchitis (infection of the testicles)
Venereal tumors
Perineal hernia (abdominal organs bulging out of rectum)
Inguinal hernia with potential organ strangulation

FEMALES
Breast cancer
Cystic endometrial hyperplasia and pyometra
False pregnancies
Mastitis (can occur during false pregnancy)
Transmissible venereal sarcoma
Ovarian and uterine tumors
Cystic ovaries and hyperestrogenism
Chronic endometritis
Vaginal hyperplasia and prolapse
Uterine torsion or uterine prolapse

Peace of Mind
Did you know that a spayed or neutered (sterilized) animal is better behaved?
Males -- Neutered dogs focus their attention on their human families. On the other hand, unsterilized, unsupervised males roam in search of a mate, risking injury in traffic and in fights with other males. They mark territory by spraying strong-smelling urine on surfaces.
Indoors, male dogs may embarrass you by mounting furniture and human legs when stimulated. Don't confuse aggressiveness with protectiveness; a neutered dog protects his home and family just as well as an unneutered dog, and many aggression problems can be avoided by early neutering.
Females -- Female dogs generally have a bloody discharge for about a week, and can conceive for another week or so.

Good Medicine
Did you know that a spayed or neutered animal will live a longer, healthier life?
Spaying a female (removing the ovaries and uterus) or neutering a male (removing the testicles) are veterinary procedures performed with the same general anesthesia used in human medicine. Both surgeries usually require minimal hospitalization.
Neutering a male dog by 6 months of age prevents testicular cancer, prostate disease and hernias. Spaying a female dog helps prevent pyometra (a pus-filled uterus) and breast cancer; having this done before the first heat offers the best protection from these diseases. Treatment of pyometra requires hospitalization, intravenous (IV) fluids, antibiotics and spaying. Breast cancer can be fatal in about 50 percent of female dogs. With an older, seriously ill animal, anesthesia and surgery are complicated and costly.

Responsible Care
Did you know that you can help prevent the suffering and death of millions of animals?
One dog who has babies and whose babies have babies can be responsible for the birth of up to 50 puppies in one year! Almost everyone loves puppies, but some people lose interest when these animals grow up. As a result, millions dogs of all ages and breeds are euthanized annually or suffer as strays. Rarely surviving for more than a few years on their own, strays die painfully by starvation, disease, freezing or being hit by cars.

Just the Facts, Please
Myth: A female dog should have a litter before she is spayed.
Fact: The sooner you spay your female, the better her health will be in the future. As long as a puppy weighs more than 10 pounds and is 5 months old, he or she can be neutered or spayed. Many veterinarians are practicing perfectly safe early sterilization. The likelihood of developing mammary tumors or uterine infections increases the longer a female goes unsprayed. In fact, a female spayed before sexual maturity (6 to 9 months of age) has one seventh the risk of an intact female of developing mammary cancer.

Myth: Spaying or neutering (sterilization) will alter my pet's personality.
Fact: Any slight changes will be positive. Regardless of the age when spayed or neutered, your pet will remain a caring, loving and protective companion. Neutering will reduce the need to breed, and that has a calming effect on many animals. Neutered males tend to stop roaming and fighting and lose the desire to mark their territory with urine.

Myth: Companion animals will become fat and lazy if they are neutered.
Fact: Absolutely not! Lack of exercise and overfeeding make pets fat and lazy -- not neutering. Your pet will not gain weight if you provide exercise and monitor food intake. Neutering is good for your pet, since sterilized pets tend to live an average of two to three years longer than unsterilized pets.

Myth: Sterilization is a dangerous and painful surgery for my pet.
Fact: Spaying and neutering are the most common surgeries performed on animals. With a minimal amount of home care, your pet will resume normal behavior in a couple of days.

Myth: Children should witness the miracle of birth.
Fact: Countless books and videos are available to teach your children about birth in a responsible manner. Letting your pet produce offspring you have no intention of keeping is teaching your children irresponsibility. Anyone who has seen an animal euthanized in a shelter for lack of a home knows the truth behind this dangerous myth.