Understanding Pyometra: Why Emergency Surgery Can Save Your Pet’s Life

Pyometra is a life-threatening infection of the uterus that affects unspayed female dogs and, less commonly, cats. Without prompt treatment, it can lead to sepsis, organ failure, and death. The condition requires emergency veterinary care, often in the form of surgical removal of the infected uterus (spay).

At Liberty Veterinary Hospital in Liberty Township, Ohio, we want pet owners to be informed about the risks of pyometra, the importance of early detection, and why spaying is the best prevention.

What Is Pyometra?

Pyometra is a severe bacterial infection of the uterus that occurs in unspayed female dogs and cats, usually a few weeks after their heat cycle. Hormonal changes cause the uterine lining to thicken, creating an ideal environment for bacteria to grow.

The condition progresses rapidly, leading to a buildup of pus and toxins in the uterus, which can spill into the bloodstream, causing septic shock.

Types of Pyometra

  • Open Pyometra – The cervix remains open, allowing pus to drain from the body. Owners may notice vaginal discharge, which can help with earlier detection.
  • Closed Pyometra – The cervix is sealed, trapping infection inside the uterus. This is far more dangerous, as symptoms can be sudden and severe, leading to rapid deterioration.

Learn more about pyometra in dogs from Cornell University’s Canine Health Center.

Signs and Symptoms of Pyometra

Pyometra symptoms can appear within 2–8 weeks after a heat cycle and worsen quickly. Look out for:

  • Increased thirst and urination
  • Lethargy and weakness
  • Loss of appetite
  • Vomiting or diarrhea
  • Fever
  • Swollen abdomen (due to an enlarged uterus)
  • Vaginal discharge (thick, yellow, or bloody in open pyometra)
  • Collapse or shock (in severe cases)

 Emergency Alert: If your pet has a bloated belly, extreme lethargy, or sudden collapse, seek immediate veterinary care.

What Causes Pyometra?

The primary cause of pyometra is hormonal changes in unspayed females. During the reproductive cycle:

  1. The uterus thickens in preparation for pregnancy.
  2. If pregnancy doesn’t occur, the uterine lining continues to build up.
  3. Bacteria (especially E. coli) can enter and cause a severe infection.

Certain factors increase the risk:

  • Age – Pyometra is more common in middle-aged and older unspayed females.
  • Repeated heat cycles – The more heat cycles a pet goes through, the higher the risk.
  • Hormonal medications – Drugs used to prevent heat cycles can disrupt the uterus’s natural defenses.

For a deeper look at how a dog’s reproductive cycle affects their health, read AAHA’s guide on a dog’s life stages.

Diagnosing Pyometra

A veterinarian will diagnose pyometra using:

  • Physical exam – Checking for fever, dehydration, or an enlarged abdomen.
  • Bloodwork – Elevated white blood cell count and kidney changes indicate infection.
  • X-rays or ultrasound – Helps confirm an enlarged, fluid-filled uterus.

Once diagnosed, immediate treatment is crucial to prevent complications.

How Is Pyometra Treated?

Emergency Surgery: Ovariohysterectomy (Spay)

The best and most effective treatment for pyometra is an emergency spay, where the uterus and ovaries are surgically removed. This:

  • Removes the source of infection
  • Prevents recurrence
  • Has the highest survival rate when performed early

Medical Management (Rare Cases Only)

For pets that cannot undergo surgery due to severe illness, antibiotics and hormone therapy may be attempted. However, this is risky, and recurrence is common.

For more details on surgical treatment, visit the American College of Veterinary Surgeons (ACVS) pyometra guide.

Can Pyometra Be Prevented?

Yes! Spaying your pet is the only guaranteed way to prevent pyometra.

Benefits of Spaying

  • Eliminates the risk of pyometra
  • Prevents unwanted pregnancies
  • Reduces the risk of mammary tumors
  • Eliminates heat cycles and associated behaviors

Spaying is a routine and safe procedure. Learn more from the ASPCA’s guide to spaying and neutering.

If your pet is still intact, talk to our veterinarians about scheduling a spay surgery at Liberty Veterinary Hospital.

When to See a Veterinarian

Seek immediate veterinary care if your pet shows signs of pyometra. This condition is a true emergency, and delaying treatment can be fatal.

If your pet is unspayed, consider scheduling a spay procedure to prevent this life-threatening condition.

Have questions? Contact us today to discuss your pet’s health.
Ready to schedule a spay? Request an appointment here