OVARIOHYSTERECTOMY

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Surgery (General & Soft Tissue)

DEFINITION AND INDICATIONS

Ovariohysterectomy (spay, OVH, OHE, neuter) is a surgical procedure in which both ovaries and most of the uterus are removed. It is most commonly performed to prevent reproduction, and helps to control pet overpopulation. Other benefits include reducing some behavior problems; reducing the risk of uterine, ovarian, and mammary neoplasia; and preventing pyometra.

Early spaying of dogs has been found to reduce the development of mammary gland neoplasia significantly. If OHE is performed prior to first estrus, the risk of developing mammary tumors is less than one percent. If OHE is performed following the first estrus, the risk of developing mammary tumors is about eight percent. If OHE is performed after the second estrus or not performed at all, the risk of developing mammary tumors is about 25 percent.

Most animals presented for elective ovariohysterectomy are healthy. Dogs or cats with ovarian or uterine pathology require a more extensive evaluation and treatment than that described below.

PREOPERATIVE CONCERNS

• Clinical signs and history - Some animals may not have reached puberty and others may have experienced multiple estrus cycles. In breeds prone to bleeding disorders, such as Doberman pinschers, be sure to assess the animal for bleeding tendencies. Be sure that vaccination status is up to date prior to admission to the hospital.
• Physical examination -Often normal but some dogs my show evidence of estrus (swollen vulva, vaginal discharge). Some cats may show signs of estrus with characteristic behavior changes. Carefully evaluate the reproductive and urinary systems for abnormalities. Examine the ventral abdominal skin to rule out pyoderma in the area where the incision will be made.
• Diagnostic tests -Extensive preoperative work-up is usually unnecessary for healthy young dogs and cats. Packed cell volume and serum total protein serve as an adequate database prior to anesthesia and surgery. Buccal mucosal bleeding time or other coagulation tests should be performed on dogs that are suspected of having bleeding disorders.

ANESTHETIC CONSIDERATIONS

• Induction agents - Most animals tolerate a variety of induction agents. However, barbiturates should be avoided in sight-hounds.
• Special anesthesia concerns - None

PREOPERATIVE PREPARATION

• Antibiotics - Not necessary since this is a clean operation.
• Patient preparation - The mid- to caudal abdomen should be shaved and scrubbed.
• Positioning - The patient is placed in dorsal recumbency with the legs securely fastened to the surgical table to prevent rotation during surgery.

SURGICAL TREATMENT

• Approach, suture and special instruments, procedure and technique -The surgery is performed through a ventral midline abdominal incision from the umbilicus to the pubis. The ovaries are exposed by carefully breaking the suspensory ligaments. Both ovaries and uterus are removed using the standard 3-clamp technique. Absorbable suture or hemoclips are used to ligate ovarian and uterine vessels. The uterine body is double ligated just cranial to the cervix. Transfixing ligatures are recommended in medium to large dogs, or if the animal is in estrus or has a pyometra or pregnant uterus. After ligation, the ovaries and uterus are removed and the abdomen carefully checked for residual bleeding. It is important to remove as much of the uterine body as possible down to the level of the cervix. Residual uterine body tissue left in the animal increases the risk of a uterine stump pyometra or uterine neoplasia. The abdominal incision is closed routinely.

PAIN MANAGEMENT

Postoperative analgesics are recommended. Buprenorphine, butorphanol, morphine, hydromorphone or ketoprofen are commonly used.

POSTOPERATIVE CARE

• During hospitalization - A warm, dark, quiet area is recommended during recovery immediately following surgery. Analgesics are recommended during the hospital stay.
• Home care - Activity and exercise should be restricted to reduce the risk of dehiscence or other incisional complications like seroma. Some animals may benefit from continued analgesics. An Elizabethan collar or abdominal bandage may be necessary for those animals that persistently lick or chew at the incision.
• Long-term care/convalescence - Not necessary. Most animals return to normal activity and behavior in three to five days following surgery.

POTENTIAL COMPLICATIONS

• Excessive granulation tissue at the incision site
• Dehiscence
• Peritonitis
• Hemorrhage
• Stump pyometra
• Residual ovarian remnant syndrome
• Incisional infection
• Rarely, urinary incontinence

PROGNOSIS

The prognosis following ovariohysterectomy is excellent. Complications are rare. Weight gain is a common development after ovariohysterectomy.

FOLLOW-UP

Suture removal and re-evaluation is necessary 10 to 14 days following surgery. Further follow-up is usually not necessary unless complications have occurred.