CVMA-ACMV

Spay Surgery: What You Need to Know

October 24, 2012

A spay surgery is the operation done on female dogs and cats to make sure they cannot have babies. Spay surgery when in Canada is usually an ovariohysterectomy, which means both the ovaries and the uterus are removed. 

The spay procedure requires a general anesthetic, sometimes supplemented with local anesthetic or epidurals. The animal does not feel anything during the procedure, and pain medicines and possibly other analgesia-inducing modalities are used around the surgery time and afterward to ensure patient comfort.

The animal usually will have preoperative blood work done to check for good organ function and general health. Monitoring of the vitals will be done throughout the procedure to make sure anesthesia is stable and to ensure that the patient maintains desirable heart rate, blood pressure, temperature, and depth of anesthesia. Close monitoring is done to ensure the animal cannot feel anything, and goes under anesthesia and wakes up safely.

If everything checks out on the pre-op evaluation, the animal will anesthetized, intubated with an ET or endotracheal tube, then be shaved and “prepped”, meaning the skin over and around the incision is scrubbed with antibacterial solution. The animal will be transferred to a surgical suite and placed tummy side up on the warmed surgery table. The gas anesthesia will continue throughout the procedure. Sterile drapes are used to isolate the prepped skin and maintain asepsis (sterility). 

Once the surgeon has the drapes in place, the surgery begins. An incision is made along the midline of the tummy, and the spay hook is used to catch the first uterus horn. It is gently brought up outside the body (exteriorized) after the ovarian ligament is stretched or torn so that the blood supply can be tied off. Clamps are used to steady the tissue that is being tied. The second ovary is found by travelling along the one horn then gently pulling out the second horn. The same steps are taken and the uterus is rotated back and a final tie off is done at the cervix level. 

Each tied off “stump” is examined for blood leakage. The abdomen is examined again for leakage and the closing phase of the operation begins. The body wall layer is first closed, followed by the subcutaneous (under the skin) and then either subcuticular (just below the skin) or skin sutures/staples are placed. Absorbable or non absorbable sutures may be selected for skin, but usually are removed at the post op check in 8-12 days. Staples usually are removed at about the same time. If there are no skin sutures, the subcuticular layer will absorb—this layer is never removed as the skin seals over top of it.

Complications intra-op are unusual but do occur. 

Anesthetic complications

Rare reactions do occur, and the risk cannot necessarily be identified in the pre-op physical and diagnostic evaluations. Each clinic has emergency drugs and protocols to manage any such unusual events. 

Surgical and post-op complications

During surgery, blood loss and low blood pressure can occur, and these complications are more common in pregnant or in-heat animals. The blood supply is less developed before the first heat so many clinics favour spaying at about 5 months old to help reduce hemorrhage risk. Most clinics prefer to do the surgery when she is not near her heat.

Post-op, there are many possible concerns though they are uncommon, and some very rare. Most commonly, swelling and suture reaction, or irritation may occur if the animal is sensitive to the suture material or they are allowed to be too active after surgery while healing. Infection of the surgery areas can occur, leading to red, swelling, pain and discharge from the incision. Fever, loss of appetite or lethargy may indicate a developing infection. Dehiscense (breakdown) of the surgery closure is rare but life threatening, since contents of the abdomen may come out, so any increasing swelling post op should be checked by your veterinarian promptly.

Excess and unwanted pets are a serious concern for society, so any non-purebred dog or cat that does not belong to a qualified breeder and is not in a formal breeding program should be spayed.