An Ovariohysterectomy [OHE] or spay is the the complete removal of the female reproductive tract (ovaries, oviducts, uterine horns, and uterus). Not only does this procedure prevent the animal from becoming pregnant, it also eliminates the twice-yearly heat cycles.
The surgery removes the sources of production for such hormones as estrogen and progesterone. These hormones are responsible for stimulating and controlling heat cycles and have a major roles during pregnancy. Howerver, they also have other effects on the body and some of them are potentially harmful.
Disadvantages of Not Spaying
During the heat cycle there are behavior and hygenic problems that develop. Females in heat will actively search out male dogs and may attempt to escape from the house or yard. This activity puts them in danger of traffic or fights with other animals, and often there is a sudden influx of male dogs around the home and yard. Owners also need to contend with the vaginal bleeding that typically lasts for 4 to 13 days.
Estrogen is one of the primary causes of canine mammary cancer, and the most common malignant tumor in dogs. Animals that are spayed prior to one year of age rarely develop this malignancy. Spaying a dog before her first heat is the best way to significantly reduce the chance your dog will develop mammary cancer. The risk of malignant mammary tumors in dogs payed prior to their first first heat is 0.05%. It is 8% for dogs spayed after one heat and 26% in dogs spayed after their second heat.
Tumors of The Reproductive Tract
Tumors can occur in the uterus and ovaries. Spaying would, of course, eliminate any possibility of this occuring.
Many female dogs have problems with a severe uterine disease called pyometra following their heat cycles. With this disorder, a normal three-ounce uterus can weigh ten to fifteen pounds and be filled solely with pus. Undetected, this condition is always fatal.
Its treatment requires either the use of expensive hormonal and IV fluid therapy or an extremely difficult and expensive ovariohysterectomy. A normal spay costs between $100 and $150, while one done to correct a pyometra can cost between $600 and $1000, depending on complications. The strain on the kidneys or heart in some cases may be fatal or cause life long problems, even after the infected uterus has been removed.
In the United States, most dogs are spayed between 5 and 8 months of age. Many humane shelters and veterinarians are starting to spay female animals at a younger age, even at 2 months. This early spaying does not affect the growth rate, and there are no appreciable differences in skeletal, physical, or behavioral development between those animals spayed early than those spayed at a more traditional age often have faster recoveries than those spayed when they are older.