Pyometra

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.  

https://www.petmd.com/cat/conditions/reproductive/pyometra-cats-what-it-and-how-do-vets-treat-it