In addition to the obvious benefits of controlling pet overpopulation, spaying is one of the most important steps you can take to protect the health of a female dog. When female dogs age, they have a high incidence of mammary cancer and uterine infection. Both can be prevented by spaying.
Mammary cancer is just as serious in dogs as it is in people. In some dogs, as soon as they start having knots in their mammary glands, the knots grow very rapidly into large mammary cancers. In others. the growths may stay small for years but eventually will start to grow. The cancer will spread into the lymph nodes and other organs. When mammary cancer extends into the skin, it usually widens out rapidly and is difficult or impossible to remove surgically. Many mammary cancers grow so rapidly, they outgrow their blood supply. Part of the tumor dies the dead part opens through the skin it becomes infected and smells terrible. The dog is miserable. When a female dog is spayed before her first season, her chance of getting mammary cancer is almost nil. If she is spayed after only a few seasons, her chance of developing mammary cancer is still very small. A female spayed after several seasons and a litter or two has a small risk of mammary cancer, but not nearly as high of risk as if she is not spayed. When the intact female dog reaches even five years of age, her chance of developing mammary cancer increases every year.
Mammary cancer can be treated by surgically removing the mammary glands before the cancer has spread. If the dog is spayed at the same time, the chance of the mammary cancer recurring is greatly reduced. Even though it can be treated, mammary cancer is one of those diseases for which the best "treatment" is prevention - spaying before mammary cancer develops. Uterine infection, called pyometra, is very common in female dogs. Pyometra is a life threatening disease. Because the uterus is a hollow organ, it fills with pus. Because the uterus lies in the abdomen and the abdomen is lower than the pelvis, the uterus does not readily drain. If not treated, pyometra progresses rapidly to septicemia (blood poisoning} and/or kidney failure. The best treatment for pyometra is always spaying, removing the infected uterus. And of course spaying the healthy dog is the way to prevent uterine infection.
Ovarian cysts and ovarian tumors are not as common as uterine infection and mammary cancer. However, they are not rare. They can be prevented by spaying.
Inform anyone who has a female dog of the risks of not spaying. Encourage the new owner of a female pup to spay her at about six months of age. This will give her time to mature. Never say your dog is too old to spay. If she is "old" she is getting to the time in life when her chances of mammary cancer or uterine infection are greatest. It is less risky to spay a seven year old healthy dog than to have to remove mammary cancer and spay her at nine. There is less danger in spaying a healthy dog at ten than to have to spay a dog sick with a uterine infection at eleven.
Ovariectomy (removing only the ovaries), hysterectomy (removing only the uterus) and tubal ligation (tying off the Fallopian tubes) are not acceptable for the female dog. Ovariectomy leaves the uterus in to become infected. Hysterectomy leaves the ovaries to produce hormones that trigger development of mammary cancer and make the female appear to be in season. Tubal ligation leaves both the uterus and ovaries in to cause trouble. When we refer to "spaying," we mean an ovariohysterectomy - surgically removing the uterus and both ovaries.
The only valid reasons to not spay a female dog are because you want to exhibit her at dog shows or you want to breed her. All the other reasons you have heard are just old wives' tales. There is no beneficial ·effect in "letting her have one litter before we spay her." Spaying is not going to "change her personality." And dogs do not get fat because they have been spayed. They get fat because they are fed too much and exercised too little.
