What is the procedure for having my dog spayed?
Spay is the common term used to describe the surgical procedure known as an ovariohysterectomy. The ovaries and uterus are removed completely in order to sterilize a female dog. The timing of this surgery has been debated more recently, with evidence to support the benefits of spaying at an older age. However, when a bitch is no longer going to be a part of a breeding program, having her spayed can prevent some major medical problems, such as pyometra (toxic infected uterus) and cancer of the ovaries, uterus and mammary glands.
Bloodwork should be done before the surgery to check for good organ function and general health. A chemistry panel will show any potential problems with kidney, liver, pancreatic, protein and electrolyte values. A complete blood count indicates the level of white and red blood cells. Anemia (low red blood cell count) or infection (high white blood cell count) could lead to life-threatening complications during anesthesia and surgery.
The ovariohysterectomy surgery is done while the dog is under general anesthesia. First, a small intravenous catheter, or port, is placed in the front leg. An injection is given to relieve pain and make her drowsy. She is then intubated with a breathing tube positioned in her throat and airway. Monitors are put in place to watch the body temperature, heart rate, blood pressure, oxygen level and breathing during the surgery.
The area on her abdomen is shaved and “prepped,” meaning the skin over and around the place where the incision is made is scrubbed with an antibacterial solution, usually Betadine, and then swabbed with alcohol. The alternating scrubbing and swabbing are repeated at least three times. Sterile drapes are used to isolate the prepped skin and maintain a sterile surgical field.
Once the surgeon has the drapes in place, an incision is made below the navel. Depending upon the age and size of the dog, the incision may be small or large. The uterus is gently brought up through the incision one horn at a time. The ovaries are located at the end of each uterine horn. The ligaments holding the ovary to the body wall are stretched and clamps are placed. Ligatures, or ties, of suture material are placed around the ovarian ligaments so that the blood supply can be tied off.
When both ovaries have been located, clamped, tied off and cut, sutures are placed around the body of the uterus at the level of the cervix. In larger or older dogs, ligatures are also placed around the main uterine blood vessels. The surgeon then makes a swift cut with a scalpel and removes the uterus.
Each ligated, or tied off, “stump” of both ovaries and the uterus is examined for bleeding. Sterile gauze is used to swab the abdomen to check for bleeding. When the surgeon is certain the stumps are secure, the closing phase of the surgery begins.
The body wall layer of the abdomen is closed first, followed by the subcutaneous (under the skin) layer. For both of these layers, absorbable suture material is used. The size and strength of the suture used depends on the size and age of the dog. The skin is closed with non-absorbable suture material. These stitches need to be removed in 10 to 14 days.
Stainless-steel staples may also be used to close the skin incision. Staples are nice because they are quick to place and cause minimal skin reaction. The disadvantages are they may not be strong enough to hold the skin together in a large, active dog, and can be tricky and uncomfortable to remove if they twist or get embedded in the skin.
What complications could occur with spay surgery?
Any procedure requiring anesthesia carries the risk of an anesthetic reaction. While these are rare, they do happen. Veterinarians have emergency drugs and protocols to manage these unusual events. This is why pre-operative bloodwork and a full physical examination are critically important before administering any general anesthesia.
During surgery, low blood pressure and blood loss can occur. These complications are more common when the bitch is pregnant or in heat. It is preferable to have your bitch spayed when she is not near her estrus cycle. Spaying at the time of a Caesarian section is risky since it greatly extends the time the bitch is under anesthesia. The bitch may go into shock as a result of the increased blood loss. I never recommend electively spaying at the time of a C-section.
Swelling and suture reaction at the incision site are seen when the dog is able to lick at the area or is allowed to be too active after surgery. Fever, lethargy, loss of appetite and discharge from the incision may indicate infection of the surgical site. The administration of the drug maropitant citrate (Cerenia) greatly reduces post-operative nausea and vomiting. Most bitches eat normally even on the evening of their surgery when they are given Cerenia pre-operatively.
Dehiscence is the term for breakdown of the surgical closure. This is a rare but potentially life-threatening complication, especially if contents of the abdomen, usually fat or intestines, come out. Any swelling of the surgical area should be checked by your veterinarian promptly.
You can minimize the risk of complications like infection and dehiscence by preventing your dog from licking the surgery site. An Elizabethan collar, inflatable or stuffed donut collar, or surgical suit can be worn during the healing process until the sutures are removed.
Are there alternative procedures for spaying a female dog?
One alternative to the traditional spay technique described above is the ovariectomy, in which only the ovaries are removed, while the uterus is left in place in the abdomen. Once the ovaries are removed, the uterus shrinks. This procedure has been practiced in Europe and other locations for decades. No increase in the number of dogs developing uterine disease including pyometra or uterine cancer has been reported.
An ovariectomy sterilizes the dog so she is unable to reproduce. It also eliminates her heat cycle and breeding instinct-related behavior.
The ovariectomy surgery is less invasive and faster than an ovariohysterectomy. This also means the anesthesia time is shorter. One important limitation of the ovariectomy is that it should be performed on young, healthy bitches with a healthy uterus. The ovariohysterectomy is still recommended for older female dogs.
Ovariectomies can also be done laparoscopically. Instead of making a larger incision at the umbilicus, one to three small incisions are made along the abdominal body wall. Through these small incisions the surgeon places ports allowing the entrance of the camera and instrumentation. Next the dog’s abdomen is filled with CO2 gas for better visualization.
The camera transmits a digital image to a screen in the operating room, which allows full view of the entire abdomen and all organs. After sealing the ovarian blood vessels, the ovaries are transected and removed. The surgeon’s hands never enter the abdomen.
Some experts say the laparoscopic spay is safer because there is less trauma to the tissues, less risk of infection and less bleeding. Others maintain the skill of the surgeon is the key to success with either procedure. Surgeons performing laparoscopic procedures always discuss with owners the possibility of needing to convert to an open approach if complications arise, such as poor visualization, equipment malfunction or uncontrolled bleeding.
The laparoscopic technique is not suitable for very small dogs since the placement of the equipment would be too difficult. Other poor candidates include bitches with an infected or cancerous uterus, or bitches that are actively in heat.
Laparoscopic spays usually cost more than traditional spays due to the special equipment and training required. Many feel the extra cost is well worth it.
An ovary-sparing, or “partial spay,” is where one or both ovaries are left in place in the abdomen near the kidneys, but the uterus and cervix are removed. It is important to remove the uterus completely to ensure a pyometra does not develop in the remaining uterine tissue. The bitch will still have heat cycles due to the influence of hormones on her ovaries, but removing the uterus eliminates the bleeding during estrus as well as the possibility of pregnancy.
When the ovaries are left intact, the bitch is less likely to develop urinary incontinence and other musculoskeletal problems associated with the absence of hormones. However, the risk of cancer of the ovaries and mammary glands remains.
Tubal ligation has also been practiced in dogs, but pyometra remains a risk, as well as bleeding during the heat cycle. This makes the ovary-sparing spay a better option.