Pyometra in Cats: What Is It and How Do Vets Treat It?

If you’re contemplating whether to have your cat spayed and have heard about the risk of her getting pyometra in the future, then read on to understand what pyometra is and the life-threatening risks it poses to an unspayed cat.  

What Is Pyometra in Cats?

Pyometra in cats occurs when a feline has a pus-filled uterus. This condition is a bacterial infection that is a medical and surgical emergency. Without prompt veterinary care, pyometra will result in death.  

Fortunately, the condition can be prevented with a routine spay procedure. 

Pyometra develops because of cystic endometrial hyperplasia (CEH).  

With each heat cycle (estrus), as the uterus gets ready for pregnancy and the cervix relaxes, hormones cause the uterine lining to get bigger and thicker (endometrium). Over time and with multiple heat cycles, tissue grows more and more, and cysts will form. These cysts create fluid within the uterus, which is an environment ripe for bacterial growth.  

Bacteria from the vagina can get into the uterus, and it can become infected with pus. These bacteria also send out toxins that can get into the bloodstream, causing endotoxemia and sepsis.  

Symptoms of Pyometra in Cats

Symptoms of pyometra in cats can be vague but often include:  

• Decreased appetite 

• Fever 

• Weight change (loss or gain) 

• Increased thirst and urination 

• Lethargy 

• Dehydration 

• Bloody or purulent (pus-filled) vulvar discharge, which may not always be noticeable because of the grooming behavior of cats 

• Distended (enlarged) or tender abdomen 

• Vomiting and diarrhea 

• Increased heart rate 

• Increased respiratory rate 

• Unkempt haircoat 

Causes of Pyometra in Cats

Pyometra is an infection of the uterus, which is often caused by the bacteria E. coli, Streptococcus, and Staphylococcus spp.  

Thankfully, pyometra is not as common in cats as in dogs with only about 2.2% of cats less than 13 years old being diagnosed with the condition.  

Typically, cats older than five years of age are at higher risk (but not always!), and there may be a genetic predisposition as pyometra is more common in oriental breeds like Sphynx, Siamese, Ragdoll, and Bengal. 

Other cats with higher risk include unspayed females who had drugs containing estrogen and progesterone (Incurin, diethylstilbesterol)  in the past.  

How Veterinarians Diagnose Pyometra in Cats

The first thing your veterinarian will most likely recommend after doing a thorough physical exam is blood work and urinalysis followed by radiographs (X-rays) and/or ultrasound. An abdominal ultrasound is the best tool for diagnosis. 

Results from these tests can not only diagnose the condition but can give important information about how severe the infection is, any inflammation (swelling) present, and the need for stabilization before having surgery.  

More advanced diagnostics are rarely needed.  

Upon arrival at the vet office, share your cat’s full medical history ,including whether she has been spayed, and if not, her most recent heat cycle (if known), prior pregnancies or mating, as well as current and past parasite control and any medications they are currently taking. 

Treatment of Pyometra in Cats

Treatment of pyometra is the surgical removal of the uterus and ovaries, often known as an ovariohysterectomy (OVH), which is curative.  

Although the surgery itself is routine, most cats with pyometra are not stable and the uterus more friable (easier to tear), so the risks of surgery (and anesthesia) are greater.  

Often before surgery, the cat is stabilized and given IV fluids, pain medications, and even antibiotics (such as Clavamox, Convenia, or Zeniquin), which are often continued for a few weeks once discharged.  

Depending on the severity of your cat’s condition, hospitalization for a few days may be needed.  

Most likely, your cat will be sent home with pain medications like gabapentin or buprenorphine and a recovery cone or a recovery suit to prevent her from licking or chewing the incision site.  

There is an alternative treatment for young, healthy, and breeding cats, but it’s rarely done since the risks are greater than those for surgical treatment.  

Patient criteria is very selective—speak to your veterinarian about the best treatment options for your cat. 

These cats may get prostaglandin injections instead of surgery. The goal of this medical therapy is to cause the uterus to contract (squeeze), pushing out the infection while keeping the cat’s ability to breed. 

Recovery and Management of Pyometra in Cats

Pyometra in cats carries a good outlook overall, with a 5.6% fatality rate in cats. Early intervention leads to a higher likelihood of survival. 

Recovery time after surgery is typically two weeks, which lets the cut heal and lab values return to normal. There is not much aftercare needed once your cat is sent home, but it’s important to make sure her incision site is clean and dry and to check the incision for any signs of infection (redness, discharge, excessive bruising) at least daily.  

Keep your cat from licking or chewing at the incision site at all—it only takes a few seconds for infection or self-trauma to occur. 

Your cat should wear a recovery collar or recovery suit, as this is the most effective manner of preventing your cat from irritating her incision, causing complications. 

There are rarely external stitches used for this procedure; however, if stitches are there, they usually are removed in two weeks at the follow-up exam. 

Be sure to give all medications as directed by your veterinarian. 

Prevention of Pyometra in Cats

Pyometra in cats is 100% preventable.  

Spaying your cat involves the surgical removal of her reproductive organs, which means she cannot get the disease. Depending on the overall health of the cat, surgery can be done at any age as a preventative measure.  

Spaying at a younger age while your cat is healthy is also less expensive than pyometra surgery, as there are many low-cost facilities and discounts offered to make spaying your cat more affordable.