To Spay or Not to Spay.

Recently, at the Family Pet Hospital, we have performed two emergency surgeries due to pyometra. Fortunately, both dogs recovered fully. Pyometra in a dog is a very serious condition. Before we look at what pyometra is, let’s review the best way to avoid pyometra….and that is the ovariohysterectomy (spay) procedure.

The word pyometra is derived from the latin “pyo” meaning pus and “metra” meaning uterus. The pyometra is an abscessed, pus-filled uterus. Toxins and bacteria leak across the uterine walls and into the bloodstream causing life-threatening toxic effects. Without treatment death is inevitable.

Usually, the patient is an older female dog. (Pyometra can occur in cats but it’s not nearly as common.) Usually, she has finished a heat cycle in the previous 1-2 months. Symptoms include a poor appetite and she may be vomiting or drinking an excessive amount of water. In the more common “open pyometra” the cervix is open and the purulent uterine content is able to drip out thus a smelly vaginal discharge is usually apparent.

In the less common “closed pyometra” the cervix is closed. In these cases, there is no vaginal discharge and the clinical presentation is more difficult to diagnose. These patients also tend to be sicker than those with open pyometra due to retention of the toxic uterine contents.

Lab work shows a pattern typical of widespread infection, which is often helpful in narrowing down the diagnosis. Radiographs may show a gigantic distended uterus though sometimes this is not obvious and ultrasound is needed to confirm the diagnosis.

With each heat cycle, the uterine lining engorges in preparation for pregnancy. Eventually, some tissue engorgement becomes excessive or persistent. This lush glandular tissue is ripe for infection. Bacteria ascend from the vagina and the uterus becomes infected and ultimately pus filled. A patient with a uterus swollen with a foul and putrid “soup”, is simply carrying a bucket of poison that would eventually kill the cat or dog. These pyometra patients, once recovered, act like puppies once their near death experience is over!

The usual treatment for pyometra is surgical removal of the uterus and ovaries. The surgery is not a minor procedure. It is crucial that the infected uterine contents do not spill and that no excess hemorrhage occurs. The surgery is challenging especially if the patient is toxic. Many of these patients require I.V. fluid therapy, antibiotics and nutritional support post-operatively.

The pros: once the infected uterus is removed (with an hour or two of surgery) the infection resolves rapidly. No possibility of disease recurrence.
The cons: Surgery must be performed on a patient that could be unstable.

Having your pet spayed represents complete prevention for this condition. A spay procedure cannot be over-emphasized. Often an owner plans to breed their pet or is undecided, time passes, and then they fear she is too old to be spayed. The female dog or cat can benefit from the ovariohysterectomy procedure at any age. The best approach is to figure that pyometra will eventually occur if the female pet is left unsprayed; any perceived risks of surgery are very much out-weighed by the risk of pyometra.