Ovariectomy in Dogs

Ovariectomy is the surgical removal of a female dog's ovaries as a method of sterilization. The procedure may be performed as an alternative to the conventional spay operation. The difference being that with ovariectomy the uterine horns and body of the uterus remain inside the abdomen, whilst for an ovariohysterectomy, the entire reproductive tract is removed down to the cervix. 

Ovariectomy is gaining in popularity for the routine desexing of female dogs. The procedure itself is less traumatic for the patient because the incision is smaller and there is less traction on the reproductive tract. However, there are drawbacks, such as less visibility within the abdomen to check for hemorrhage. 

Ovariectomy can be performed in first opinion practice. Specialist referral centers may also offer laparoscopic ovariectomy, or keyhole surgery, to remove the ovaries. 

The patient is given a general anesthetic and fur clipped from the belly. Under aseptic conditions, the surgeon makes a small, two-inch incision just behind the umbilicus (belly button) to gain entry to the abdomen. The ovary is located using a spay hook or fingertip and exteriorised. The ovarian pedicle is clamped securely and transfixing sutures used to permanently ligate the ovarian artery and blood vessels. A clamp is applied between the ovary and the uterine horn, and the vessels ligated. The isolated ovary is then surgically removed. 

The muscles of the body wall are repair and the skin sutured, then the patient is woken. 

For the laparoscopic procedure, three small stab incisions are made into the body wall to facilitate the use of a laparoscope. This identifies the ovaries and uses a stapling device to isolate and remove them. A single suture at each site may be all that's needed to close the wounds in the body wall. 

Ovariectomy represents a method of permanent sterilization of the female dog. The advantages it offers over traditional surgical practice is that the surgery is less invasive and therefore the recovery time is faster. 

Alternative methods include ovariohysterectomy, which is widely taught as the standard desexing technique at US vet schools. This removes the entire female reproductive tract down to the level of the cervix. The argument in favor of this is that it eliminates the future possibility of uterine cancer or pyometra (infection in the womb). 

However, studies now show that the risk of uterine cancer is very low (0.4% of all canine cancers) and these tumors are usually benign. In addition, pyometra is unlikely unless a remnant of ovary is left behind.

Reduced handling of the womb and smaller incision size means the dog recovers more swiftly after the procedure. However, it is still important the dog rests for 10 to 14 days post surgery, in order to reduce the risk of dislodging an ovarian ligature. 

The patient must not lick her sutures and may be supplied with a cone or a dressing to cover the area. She requires a post-operative check at around three days and then a final appointment 10 to 14 days for suture removal. 

During this time she should rest and only go for gentle lead walks. Pain relief is often required for the first three to four days, and is usually given as a non-steroidal anti-inflammatory such as metacam, with the addition of tramadol if required. 

Ovariectomy via laparoscopy requires specialized equipment and therefore the procedure is more expense than a standard spay. Typically, an ovariohysterectomy costs approximately $250 to $300 (depending on variables such as the size of the dog), a laparoscopic ovariectomy is around $400 to $550. 

Alternatively, an ovariectomy via a surgical incision is often a similar price to that of an ovariohysterectomy. 

Ovariectomy is gaining interest from owners because of the faster recovery time and the perception that their pet is in less pain. Other advantages include a lesser risk of other vital structures, such as the ureter, accidentally becoming entrapped in surgical ligatures near the cervix. 

However, the small incision size does have drawbacks in that the surgeon has reduced visibility of what's going on inside the abdomen. Thus, it's more difficult to check for hemorrhage and be certain that the ligatures haven't slipped after the ovarian pedicle was released back into the abdomen. 

On the whole, ovariectomy increases the options when it comes to desexing a female dog. Experience of this technique is growing amongst veterinarians that have previously been taught ovariohysterectomy as the standard, first choice method of desexing. 

However, the continued presence of the womb means it's inadvisable to give progestogens to these dogs at any point in the future, as it could encourage uterine abnormalities and disease. 

Ovariectomy is an elective procedure that renders a female dog sterile. As such, it is not appropriate to think in terms of prevention.