08/30/2025
Everyone is familiar with the most common reasons for spaying and neutering their pets- to control pet overpopulation by preventing unwanted litters and to reduce behavioral problems like roaming, aggression, and marking. Spay/neuter also has many health benefits and helps pets live longer and healthier lives. This article addresses just one health issue that can be easily prevented in female dogs and cats, pyometra.
Pyometra is a severe and potentially fatal uterine infection in unspayed females. It is a veterinary emergency that requires immediate medical attention to prevent life-threatening complications such as sepsis and organ failure. It is a bacterial infection in the uterus, most often seen in middle-aged and older unspayed pets several weeks after a heat cycle. Pets affected develop thickened uterine linings, and the uterus fills with fluid, creating an ideal environment for bacteria to thrive. Toxins from the infection can then leak into the bloodstream, causing systemic illness.
Pyometra can present in two different ways, depending on whether the cervix is open or closed. If the cervix remains open, pus can drain from the uterus. This results in a foul-smelling, pus-like, or bloody vaginal discharge. Cats, being fastidious groomers, may hide this discharge, delaying diagnosis. If the cervix is sealed, the infection is trapped inside the uterus. This is significantly more dangerous because the buildup of pus and toxins causes a more rapid and severe illness. They may become septic and go into kidney failure, and an animal this ill faces higher risks when surgery needs to be performed to remove the uterus. If not removed, the uterus can become so large that it can even rupture, releasing the infection into the abdominal cavity and triggering life-threatening peritonitis and sepsis.
Symptoms of pyometra can appear a few weeks to months after a heat cycle and can include lethargy, increased thirst and urination, loss of appetite, vomiting,or diarrhea.
