The word pyometra can be divided into two root words :Pyo means pus, and Metra refers
to the uterus Pyometra starts after a dog goes through a heat cycle, usually within about
3 to 5 weeks. Stimulation of the uterus with abnormal levels of hormones (estrogen and
progesterone) cause the lining of the uterus to become thickened and fluid accumulates
inside the uterus. Infection develops in the uterus. As the infection progresses, the uterus
fills with pus.
The infection is life-threatening; closed pyometra (cervix is not open and pus cannot drain
to the outside )may cause a pet to become more ill than open pyometra (the pus can drain
through the cervix).
Clinical signs include: Pus may or may not drain from the vagina, increased thirst/
increased urination, enlargement of the abdomen as the uterus fills with pus, lethargy,
poor appetite, weight loss, enlargement of the abdomen, fever and dehydration.
Pyometra is a life-threatening condition, if the cervix is closed. Animals should be
hospitalized and supportive care with the administration of fluids and antibiotics begun
immediately. The preferred treatment for pyometra is a hysterectomy (spay), as this is a
condition that will re-occur every time the bitch goes through her heat cycle, unless she
In some females valued for breeding, prostaglandin and antibiotic therapy may be tried
instead of surgery. The prostaglandin is given for 5-7 days and causes the uterus to
contract and expel the fluid. In mild cases, when the cervix is still open and the fluid is
draining, the success rate is excellent. This therapy should only be used in dogs 6 years
of age or younger, who are in stable condition, and have an open cervix. Prostaglandins
can have side effects, especially after the first dose, including restlessness, panting,
vomiting, increased heart rate, fever, and defecation.
The best prevention for this condition, is to have all female animals spayed while still
young. If the animal is used for breeding, then spaying the animal after she is past her
breeding years is highly recommended. Pyometra is a fairly common and serious
problem and is just one of many compelling reasons to have your female pet spayed at
an early age.