Pyometra is a medical term used to describe an infected uterus. Dogs and cats that have not been spayed are at risk for this life-threatening infection. The problem is seen more commonly in dogs than cats, which may be because most owners spay their cats at a young age. This condition usually develops about a month after a heat cycle, and the risk of developing a pyometra increases as the animal ages.

If the cervix is open, you may notice a smelly yellow to red colored discharge from the vulva. Sometimes the cervix stays closed, so there is no discharge. Animals with a closed pyometra (cervix closed) are sicker because the pus is building up in the uterus and not draining out. Other signs that your dog may have a pyometra include lethargy, drinking and urinating more than usual, poor appetite, vomiting, and fever.

Veterinarians will have pyometra on the list of possible causes of illness in any intact (un-spayed) female dog or cat. Tests done to determine if your pet has pyometra may include ultrasound or X-rays, and blood work such as a CBC (complete blood count) and chemistry panel.

Pyometra makes pets really sick, and if left untreated for too long, death can occur. Treatment will include stabilization with IV fluids, antibiotics, and pain medication. Surgery to remove the infected uterus should be done as soon as possible. For valuable breeding animals, medical management can sometimes be attempted, but surgery is considered to be the gold standard. Since these patients are very sick, the cost of the surgery and hospitalization will cost more than an ovariohysterectomy (spay) on a healthy dog. Hospitalization for several days after surgery is often required, especially if the kidneys have been affected, or the pyometra was closed.