A spay (or ovariohysterectomy) is a surgery that removes the ovaries and uterus from female pets. In small animal medicine, this surgery is most often performed on dogs and cats, but can also be performed on rabbits, guinea pigs, reptiles, and other animals. The surgery is generally performed in order to prevent or treat diseases of the female reproductive tract and to prevent reproduction.


All animals that will not be used for breeding should be spayed or neutered. Spaying prevents ovarian and uterine cancers as well as pyometra. It also greatly reduces the risk of mammary cancer (breast cancer) in older pets. Spaying reduces some undesirable behaviors, including the desire to roam and some aggressive tendencies. It sterilizes the pet and eliminates the possibility of unwanted or unplanned pregnancy. Finally, a spay surgery may be recommended as a treatment option in the case of cancer of the reproductive tract, some pregnancy complications, pyometra, or other diseases associated with the ovaries, uterus, or mammary glands.

Patient Selection

Any female animal can be spayed. Generally the surgery is performed between 5 and 7 months of age. Some rescues spay puppies and kittens as early as 8 weeks of age. In general, the younger the patient is, the faster they recover from surgery. To receive the most benefit from spaying your pet, especially in regard to preventing mammary cancer, she should be spayed prior to her first heat cycle. However, the surgery can be performed at any age. Ideally, the patient should be spayed when she is not in heat or pregnant, as these conditions increase the risk of complications.

Risks & Complications

Thankfully, risks and complication of this surgery are rare. Spay and neuter surgeries are some of the most common surgeries performed in the average small animal hospital and the average veterinarian has ample experience with these procedures. Risks and complications, although rare, may include:

  • Excessive blood loss – the risk of blood loss is higher in those animals who are pregnant, have a pyometra, or are in heat at the time of the surgery
  • Anesthetic complications
  • Infection
  • Damage to or obstruction of a ureter
  • Incomplete removal of the ovary or uterus
  • Urinary incontinence
  • Dehiscence (the incision opening up)
  • Post-operative trauma to the incision by the patient

What To Expect

A spay surgery may be an outpatient or overnight procedure, depending on your veterinarian’s recommendations. The animal will be required to complete a 12 hour fast prior to the morning of surgery. This generally entails withholding food only – the animal should have access to water to prevent dehydration

Most often, your pet will be dropped off at the veterinary hospital early the day of her surgery. The doctor will perform an exam and run any recommended pre-anesthetic testing to ensure she is healthy enough for surgery. Once she is cleared for surgery, the patient will receive pre-anesthetic medications including sedatives and pain medication. After a short period, the patient is then induced, generally using short-acting anesthetic injectable drugs. An endotracheal (breathing) tube will be placed, and her anesthesia will be maintained using inhalant anesthesia.

While anesthetized, the patient is monitored by a licensed veterinary technician using a stethoscope, EKG, pulse oximeter, carbon dioxide monitor and blood pressure monitor. She receives thermal support with a warm-air blanket, and her temperature is monitored closely. She receives IV fluids throughout the procedure to maintain her blood pressure and hydration. The veterinary technician is present at all times to monitor anesthesia and make any necessary adjustments.

A spay surgery is a sterile procedure. The patient’s abdomen will be clipped free of hair and scrubbed using a surgical preparation solution. She will be covered with a sterile drape. The doctor will scrub, don a sterile gown and gloves, and use sterile surgical instruments to perform the surgery.

The veterinarian will make an incision in the middle of the patient’s abdomen. Through this incision, the doctor will identify and isolate each ovary, tying off all the blood vessels associated with the ovary before transecting it from the surrounding tissue. Once the ovaries are free, the doctor will extract the uterine horns. Finally, the body of the uterus is clamped and ligated, then dissected from the surrounding tissue and removed.

The doctor will check for any bleeding within the abdomen. Once satisfied that all bleeding has been stopped, the doctor will close the muscle wall with absorbable sutures. Then, the skin and subcutaneous tissues will be sutured closed. Sometimes the skin sutures are absorbable and buried within the skin; other times, sutures are placed on the surface of the skin and will require removal 10-14 days after surgery.

The anesthesia gas will be discontinued and the animal will be allowed to wake up. The endotracheal tube is not removed until the animal is awake enough to swallow and move her head. As the patient breathes off the anesthetic gas, she will gradually wake up. Pain medication is administered as needed to keep the patient comfortable during recovery.

Recovery & Post-Op Care

At the time of discharge, the owner will be instructed as to how to care for the animal during the two weeks following surgery. You will be asked to restrict activity as much as possible for 10-14 days to allow the incision to heal. The more an animal stretches and moves, the slower the incision will heal and the higher the chance of dehiscence (the incision opening up) or swelling. The patient will be sent home with several days of pain medication, and may receive an E-collar to prevent self-trauma to the incision. If surface skin sutures are placed, you will be asked to return in 10-14 days for suture removal.

Spaying your pet will reduce her metabolism, so care should be taken after her surgery to maintain a healthy weight. Depending on her age and activity level, this may require a reduction in the amount of calories ingested and/or an increase in exercise. This dietary management should be continued throughout the life of your pet.

Common Myths Regarding Spaying Your Pet

  • Myth: Spaying causes weight gain. The truth: Spaying an animal does decrease her metabolism, but too many calories coupled with too little exercise is the real cause of weight gain.
  • Myth: You should wait until after an animal’s first heat cycle to spay her. The truth: An animal’s risk of mammary cancer is dramatically decreased if she is spayed prior to her first heat. It is only moderately decreased if she is spayed after the first heat cycle.
  • Myth: You should allow your pet to have one litter of puppies/kittens before spaying her. The truth: Allowing your pet to reproduce contributes to the problem of pet overpopulation and does not benefit your pet in any way.
  • Myth: Spaying causes a change in personality. The truth: Many pets are spayed during puberty, a time for behavioral and personality changes. The surgery does not contribute in any way to these changes.
  • Myth: My pet is a purebred, so she should be bred. The truth: Just because your pet has papers does not mean she is a good candidate for breeding. Breeding dogs should be screened thoroughly for genetic abnormalities and heritable conditions, and they should be carefully matched to an equally well-screened mate. Breeding is expensive and labor-intensive; it should not be undertaken without being thoroughly researched. In addition, being purebred does not protect a dog from ending up in a shelter. Statistics show that 1 in 4 dogs in animal shelters are purebred.