Pyometrais a condition of the “intact” or un-spayed female dog or cat.
The Greek prefix “pyo” means “pus,” and the suffix “metra” refers to the uterus. Therefore, the literal translation is “pus in the uterus,” but the condition is more complex than that. Some clinicians use the term pyometritis. The “itis” suffix refers to the inflammatory component of the condition.
Pyometra has its beginnings rooted in the heat cycle, which causes swelling of the uterus, thickening of the uterine walls and collection of fluid in the lumen, or cavity of the organ. After repeated heat cycles, more fluid collects, creating a rich culture medium in which bacteria can grow.
Pet owners may notice their dog or cat drinking more and eating less. There is sometimes a vaginal discharge, which may be foul-smelling, bloody, or absent. Infection is often preceded by irregular heat cycles and pseudopregnancy, or false pregnancy. During pseudopregnancy hormone levels soar out of balance and fluid accumulates in massive amounts.
If a practitioner suspects pyometra from his physical examination, he may next perform laboratory tests. A Complete Blood Count (CBC) usually shows an elevated white blood cell (WBC) count. WBCs can be elevated to two or more times normal. White blood cell counts of 100,000 are sometimes seen in longstanding cases. Such patients are typically very ill.
A low red blood cell (RBC) count may also be present, indicating anemia caused by chronic inflammation and/or blood loss in the vaginal discharge.
Infections in the uterus often leak toxic byproducts into the bloodstream, poisoning the body from within. Therefore, the chemistry profilewill often reveal damage to the liver and/or kidneys. Such damage is usually reversible with successful surgical removal of the infected uterus.
Other helpful diagnostic procedures include abdominal X-ray and abdominal ultrasound. Uterine size can vary from pencil-sized to several inches in diameter. Smaller uteri are seen when the cervix is open and infection drains at least partially. Uterine size comparable to a balloon ready to burst occurs when the cervix acts as a seal as infection festers.
A uterus of normal diameter is virtually impossible to see on a radiograph, whereas ultrasound is much more sensitive and may even give some information about the contents of the inside of the uterus.
In valuable breeding stock, non-surgical treatments for pyometramay be considered, in hopes of successfully
draining the infection and returning the pet to fertility. Prior to entering into this process, however, the pet owner must be aware that the life of the pet hangs in the balance. Not only are success rates low, but some of the medications used are harsh and rupture of the infected uterus often results in death.
Surgical removal of the uterus and ovaries is the standard of care and is successful in the vast majority of cases. Obstacles can include the aged patient, those toxic from the disease, complicating factors such as diabetes and rupture of the uterus. Fortunately, when a pyometra case spills its infection during surgery the prognosis is better than rupture during medical treatment, because the abdominal cavity is already open and can be aggressively irrigated and disinfected.
Thanks to modern anesthetics and careful monitoring, even pets with diabetes, kidney disease and less-than-perfect livers may have safe surgical removal of an infected uterus.
As is usually the case, prevention is much easier. Have your female dog or cat spayed at a young age and pyometra is a nightmare that will never wake you up from your sound sleep.
See you tomorrow, Dr. Randolph.