A spay, also known as an ovariohysterectomy- meaning the uterus and both the ovaries are removed, is one of the most common surgical procedures performed on dogs and cats.  In this operation, the ovaries and the uterus are removed.  It is primarily used prevent unwanted litters, but it is also treats certain conditions, including pyometra, which is a potentially fatal infection of the uterus. 

How is it performed?

Your veterinarian will recommend a physical exam before the surgery make sure she is healthy enough. The pre-anesthetic blood tests will make sure your pet is able to  handle the anesthetic.  These tests are usually performed several days before the surgery, however, they may be performed the same day, before the surgery.  The night before the surgery, your vet will instruct you to take up your pet's food and water before bedtime.  If the pet eats before going under anesthesia, he may suffer a life threatening complications from vomiting while being sedated. 

Before the surgery begins the animal is first given anesthesia.  This keeps the pet still  and pain free during the operation.   There are many types of anesthesia and your veterinarian will choose the one that is best for your pet.  Some types are given as an injection, while others anesthetics are gasses that are inhaled.  A plastic tube is inserted into the animal’s trachea to protect the airway during sedation. This tube is connected to the anesthetic gas machine to give the animal a constant flow of anesthetic gas and oxygen

Once asleep, the pet's belly is shaved and scrubbed using a germicidal solution.  The area is then draped with sterile cloths that help keep the surgical area sterile.  The veterinarian and veterinary assistants then prepare for surgery through repeated hand washing with germicidal soaps and then put on sterile gowns, masks, and gloves. Keeping everything sterile helps prevent infections.

The vet starts by making the smallest possible incision with a scalpel close to the belly button.  The scalpel passes through several layers of the skin.  The last layer that is cut is called the linea alba, which means white line. The linea alba is a thick white membrane where the muscles of the belly attach along the midline.  Once the belly is open, the surgeon uses an instrument resembling a crochet hook called a spay hook The vet inserts the spay hook into the opening, slides it to the side,  and then uses it to gently pulls out the uterus.

There are two ovaries and each has its blood supply and supporting ligaments  tied off and then cut.  The vet must remove all the ovarian tissue or the pet may could still  produce enough estrogen to show signs of heat. 

Next, the uterus is clamped, and sutures placed on the vessels to permanently cut off the blood supply. After a scalpel cuts through the  uterus, the clamps are then removed and the uterine stump placed back  into the pet’s body. The removed uterus and ovaries attached are discarded.

Before closing with sutures, the surgeon checks the area for signs of bleeding. If bleeding is seen, she may need to place more sutures over blood vessels to stop the flow. Finally, the layers of the skin and muscle are closed.  The first to be sutured is the linea alba, then the subcutaneous layer, which is directly below the skin, and finally the outer skin.  The inner layer sutures are never removed.  They may either be permanent or they are dissolvable and are eventually are absorbed by the body.  The sutures in the outer skin area are removed in about week after surgery,when the skin has healed.  Sometimes veterinarians will use  dissolvable sutures in the outer skin which absorb and do not need to be removed.  

Once the surgery is complete, the anesthesia is discontinued and the incision area is cleaned.  The pet is then brought to the recovery area. Usually the patient is given an injection for pain control during this time.  Some hospitals keep the pets overnight so they can remain in a confined area, however, others will be allowed to recover at home.  Your vet may recommend that your pet wear an Elizabethan collar to prevent tampering with the stitches. This is a plastic like cone that attaches to your pet's collar and keeps them being able to reach the surgical area with their mouth and tongue.

What are the Benefits of spaying? 

There are many benefits to spaying your pet.  The most important is that it helps stop the pet overpopulation. Humane Society of the United States estimates that between 3 and 4 million unwanted pets are euthanized at shelters annually.  It can also help prevent certain types of cancers such as mammary, ovarian, and cervical cancer.  Kittens and puppies who are spayed before they enter puberty have fewer behavior problems like inappropriate elimination. And neither the pet or the owner have to endure an annoying and inconvenient  heat cycle.