Ovariohysterectomy in the Dog and Cat

The Ovariohysterectomy (OHE), or "spay" surgery, is one of the most commonly performed operations at a veterinary hospital. However, it must still be considered a major abdominal surgery. The abdominal cavity must be surgically opened and explored so that the female reproductive organs (ovaries and uterus) can be properly identified, dissected free, and removed. Great care must be taken to prevent internal bleeding and to avoid contamination of the normally sterile abdomen. Peritonitis or infection of the abdominal cavity, which can be a life-threatening complication can result if proper sterile techniques are not followed.

These sterile techniques should include the use of: a separate operating room for sterile procedures; autoclaved or steam sterilized instruments; and sterile gloves and gown worn by the surgeon who also uses a cap and mask. The techniques used in a good veterinary hospital should be the same as their human counterparts.

The OHE surgery can be done at any time after 6 months of age. The recommended age for an OHE is before the first heat cycle or pregnancy (first heat cycles usually occur between 7 and 12 months of age). There are several medical advantages to spaying at an early age:

1. Animals at this age are normally very healthy and can better handle the stress of general anesthesia and surgery.
2. The reproductive tract and the associated blood supply is smaller in an animal that has not yet been through a heat cycle. This makes the surgery less difficult and reduced the risk of complications, such as post-operative bleeding.
3. Statistics have shown that animals spayed before the first heat cycle have almost no chance of later developing breast tumors. Breast tumors are fairly common in older female pets who were spayed late (after their 2^nd heat) or never spayed at all. Over 50% of breast tumors are malignant or cancerous in the dog (over 80% in the cat).
4. Spaying eliminates the risk of accidental pregnancy. In addition to producing homeless "mix-breed" puppies or kittens, carrying a pregnancy can pose a great physiological stress on an animal's system (especially for a very young animal who is not finished growing herself). Difficult births, some of which require Cesarean delivery, are seen more frequently in first litter mothers, especially in dogs bred to a larger male.
5. Older female dogs (greater than 5 years) have an increasing risk of developing uterine infections (pyometra) within 60 to 90 days after a heat cycle. This condition is treated by performing an OHE on an emergency basis. The surgery is much more difficult on the infected uterus and the risk of complications arising from the surgery and anesthesia are much greater for the patient. For this reason, we recommend OHE on breeding females who are past their normal reproductive years.

Spaying also eliminates the management problems associated with an animal in heat:

1. In dogs this can include fending off interested male dogs as well as soilage of the house with the blood-tinged discharge seen during the 3 to 4 week heat cycle.
2. In cats the surgery will help prevent males from being attracted to your home and urine marking when your female cat is in heat. In addition, many cats in heat show dramatic behavioral changes including howling, agitation, excessive rolling, licking, tail-flagging, and increased attempts to escape to the outside. Unlike dogs which usually come into heat once every 5 to 12 months, most cats continue to come in and out of behavioral heat every 2 to 4 weeks during the Spring, Summer, and Fall seasons until they are bred and become pregnant. Cats may have 2 to 3 litters of kittens per year if left to go outside and breed.

The doctors and staff and Centre Animal Hospital are very proud of the operating facility and monitoring equipment we can offer to our clients. We invite all of our clients to take a tour of our hospital facilities. All OHE or spay operations are performed in our separate sterile surgery area, using full sterile technique as previously described. Dogs are anesthetized using inhalant gas anesthesia equipments. Cats are anesthetized using a combination of injectable agents, which may be supplemented with inhalant gas anesthesia. The anesthetized patient is monitored during the surgery by an animal health technician. We also use electrocardiogram and pulse oximetry monitoring to further ensure patient safety.

The surgery itself is performed using as small an abdominal incision as possible to permit complete access to the structures involved. The incision is then closed in two layers using synthetic absorbable sutures. Both layers are buried so no skin "stitches" are visible to the owner or patient. Both the smaller incision and the buried absorbable stitches mean less post-operative pain for you pet. Also, the pet cannot lick at or chew out the sutures and doesn't need to come back for suture removal.