Pyometra in Dogs and Cats: A Life-Threatening but Preventable Condition

Pyometra is a serious and potentially fatal infection of the uterus that affects unspayed female dogs and cats. If left untreated, this condition can rapidly lead to organ failure, septic shock, and death.

While pyometra is common, it is also entirely preventable through spaying. Understanding the causes, symptoms, and treatment options can help pet owners recognize this emergency and take life-saving action.

At Greenfield Veterinary Clinic, we are committed to educating pet owners and providing expert veterinary care to ensure the best outcomes for your pets.

What Is Pyometra?

Pyometra is a bacterial infection of the uterus that develops in unspayed females, usually following a heat cycle. Hormonal changes cause the uterine lining to thicken in preparation for pregnancy. If pregnancy does not occur, this tissue continues to accumulate, creating the perfect environment for bacterial growth.

During heat, the cervix opens, allowing bacteria—commonly E. coli—to enter. When the heat cycle ends, the cervix closes, trapping the bacteria inside and leading to a pus-filled, infected uterus.

According to Cornell University, pyometra can occur weeks to months after a heat cycle, often catching pet owners off guard.

Causes and Risk Factors

Certain factors increase the likelihood of pyometra:

  • Age: More common in middle-aged to older dogs and cats.
  • Repeated Heat Cycles: Each heat cycle increases risk, especially after age five.
  • Breed Predisposition: Larger breeds, such as Golden Retrievers, Rottweilers, and Bernese Mountain Dogs, may be more susceptible.
  • Hormonal Medications: Some progesterone-based drugs used to prevent heat can contribute to pyometra development.

Spaying your pet before their first heat cycle eliminates the risk of pyometra. Learn more about the benefits of spaying from the ASPCA.

Signs and Symptoms of Pyometra

Pyometra can present in two forms, each with different warning signs:

Open Pyometra (Less Dangerous but Still Serious)

In this form, the cervix remains open, allowing pus to drain from the uterus. Symptoms include:

  • Foul-smelling vaginal discharge (pus-like or bloody).
  • Increased thirst and urination.
  • Lethargy and reduced appetite.
  • Mild fever.

Closed Pyometra (More Dangerous and Life-Threatening)

When the cervix is sealed shut, pus accumulates inside the uterus with no way to drain. Symptoms progress rapidly and may include:

  • No visible discharge.
  • Severe abdominal swelling.
  • High fever and extreme lethargy.
  • Vomiting and diarrhea.
  • Collapse and shock in advanced cases.

If your pet exhibits any of these symptoms, seek emergency veterinary care immediately. Contact Greenfield Veterinary Clinic for urgent medical attention.

How Is Pyometra Diagnosed?

A veterinarian will confirm pyometra through:

  • Physical Exam: Checking for abdominal swelling, dehydration, and fever.
  • Blood Tests: Elevated white blood cell count and signs of kidney stress.
  • X-rays or Ultrasound: Imaging to reveal an enlarged, pus-filled uterus.

Early detection is critical—if caught in time, emergency surgery can save your pet’s life.

Treatment: What Are the Options?

1. Emergency Surgery (Ovariohysterectomy – Spay)

  • The safest and most effective treatment for pyometra.
  • Removes the infected uterus and ovaries.
  • Prevents recurrence, since the uterus is no longer present.

2. Medical Management (For Select Cases Only)

  • Used only if surgery is too risky due to underlying health conditions.
  • Involves IV fluids, antibiotics, and prostaglandins to expel infection.
  • High failure rate—many pets still require surgery later.

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

Why Spaying Prevents Pyometra

Spaying is the only guaranteed way to prevent pyometra. Benefits include:

  • Eliminates risk of uterine infections.
  • Reduces risk of mammary tumors (especially if done before the first heat cycle).
  • Prevents unwanted pregnancies and reproductive diseases.
  • More affordable than emergency surgery for pyometra.

Spaying is a simple, routine procedure that ensures a longer, healthier life for your pet. Learn more about spaying and neutering from AAHA’s pet life stage guide.

To discuss spaying options for your pet, schedule an appointment at Greenfield Veterinary Clinic.

When to Seek Veterinary Care

Call your vet immediately if your unspayed pet is showing:

  • Sudden lethargy, vomiting, or fever.
  • Bloated abdomen with or without vaginal discharge.
  • Weakness or collapse.

Time is critical—pyometra is fatal if left untreated. If you suspect your pet has pyometra, contact Greenfield Veterinary Clinic right away.

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Protect Your Pet from Pyometra

Pyometra is a silent but deadly threat to unspayed female pets. The good news? It is 100% preventable with spaying.

At Greenfield Veterinary Clinic, we provide:

  • Emergency surgery for pyometra cases.
  • Safe and effective spaying procedures.
  • Preventive care to keep your pet healthy.

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Taking action today can save your pet’s life tomorrow.