What is it?
• Pyometra is defined as an infection in the uterus.
• It occurs more often in dogs than in cats.
• The severity of the disease is determined by whether or not the cervix is open and actively draining fluids and pus.
• Some cases are caused by leftover ovarian tissue from a spay (known as stump pyometra).
What causes it?
• The hormone progesterone usually causes the uterus lining to produce a secretion.
• Pyometra is a secondary infection that occurs as a result of hormonal changes in the female reproductive tract.
• Following estrus (“heat”) in the dog, progesterone hormone levels remain elevated up to two months and cause thickening of the lining of the uterus.
• The thickened, cystic lining secretes fluids that creates an ideal environment for bacteria to grow.
• Progesterone causes the cervix to relax.
• If the cervix is open or relaxed, bacteria that are normally found in the vagina can enter the uterus and cause infection.
• Animals may have vaginal discharge, decreased appetite, depression, vomiting, diarrhea, lethargy, fever, and excessive drinking or urination.
What tests are needed?
• Because a Pyometra infection often affects other organs as well, routine laboratory tests are recommended to look for signs of infection elsewhere.
• Typically the white blood cell count spikes.
• X-rays will likely show fluid-filled structures in the uterus.
• An ultrasound or bacterial culture of uterine fluid may be needed.
How is it treated?
• The typical treatment of choice is surgery to remove the uterus and ovaries.
• Prior to surgery, most animals require aggressive fluid therapy and antibiotics.
• For a stump pyometra, the ovarian remains must be removed.
What follow up care is needed?
• Antibiotics are usually given and blood tests may be repeated until clinical signs disappear.
• Medically treated animals are monitored for any side effects.