Illnesses of Intact Pets, Part 2—Uterine Problems

This is the second of Dr. Palazzolo’s three-part series on diseases of intact pets (see part one about breast cancer here). Some of the photos may seem graphic, but it’s good to know what you’re dealing with and to attend to the signs.

In addition to breast cancer, another problem in intact female dogs and cats as well as small mammals like guinea pigs is an infected uterus. An infected uterus is called a pyometra. If you get your female spayed early in life, she will not get an infected uterus because she will not have one.

There is another version of this disease in which the cervix remains closed. The uterus becomes filled with a large amount of pus, and the dog or cat becomes toxic and ill.

distended belly

Guinea pigs get cystic ovaries and uterine infections. Look at how distended this guinea pig’s abdomen is during surgery prep. The cystic ovaries are so large that they are distending the abdomen. Photos courtesy of Long Beach Animal Hospital.

Yet another type of this disease can take place when the cervix is not closed, making it possible for the infection to drain out of the body. These pets are not as ill as the closed version but are treated the same way.

Symptoms of pyometra include lethargy, vomiting, lack of appetite, and drinking excess amounts of water. The bacterial toxins affect the internal organs, especially the kidneys. Pyometra usually occurs one to two months after the last heat.

Pyometra is diagnosed with the symptoms and history previously mentioned in an unspayed female. In the closed version, there is no discharge from the vulva; in the open version, there usually is.


Abdominal ultrasound is sometimes needed for a diagnosis when the symptoms, exam finding, blood panel, and radiographs are not definitive for pyometra.

A blood panel might reveal a normal white-blood-cell (WBC) count in an open pyometra and a very elevated WBC count in a closed pyometra. In a closed pyometra, a radiograph will commonly reveal a greatly enlarged uterus. An ultrasound is used on occasion to confirm the diagnosis in cases where the symptoms and diagnostic tests are not obvious for a pyometra.

Blood count

An elevated white blood cell (WBC) count is a good indication of pyometra when other symptoms are present. Sometimes it goes much higher than this in a closed pyometra.

Pets with a closed pyometra are very toxic and ill. They need to be treated with intravenous fluids, antibiotics, and pain medication. Surgery cannot be delayed for too long for fear of a rupture of the uterus and severe bacterial contamination of the abdomen. This problem is readily corrected by performing an ovariohysterectomy (what we commonly call spaying) once the pet is stable. Special precautions need to be taken to prevent contamination of the abdomen when removing a large and infected uterus.

Uterine cancer and cystic ovaries can also occur in intact females. We sometimes see an infected uterus in small mammals and a cancerous uterus in rabbits. In all of these cases, if the female is spayed early in life, she will not get a pyometra, uterine cancer, or cystic ovaries.

To learn more about pyometra, uterine cancer, and how we perform the surgery for these diseases, please visit the following links:

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