What Every Dog Owner Needs To Know About Pyometra Symptoms In Dogs

Your female dog is acting strange—lethargic, drinking way more water than usual, and you notice some concerning discharge. Before you panic, here’s what you should know about one of the most serious reproductive infections that can affect unspayed dogs: pyometra.

The Silent Threat: Understanding Pyometra in Dogs

Pyometra is essentially a bacterial infection of the dog’s uterus that develops when E. coli bacteria travel up through the vagina into the uterine cavity. Sounds scary? It can be—but here’s the good news: caught early, most dogs recover completely with prompt treatment.

“It typically occurs in middle-aged to older female dogs that have not been spayed,” explains Dr. Mathieu Glassman, V.M.D., a board-certified veterinary surgeon. “However, it can also develop in spayed dogs if ovarian tissue was accidentally left behind during surgery.”

The infection usually starts after a heat cycle when the dog’s progesterone levels spike, causing the uterine lining to thicken. Each heat cycle without pregnancy increases the risk—multiple cycles create the perfect breeding ground for bacterial growth and fluid accumulation.

Spotting The Warning Signs: Pyometra Symptoms in Dogs

The tricky part? Not all dogs show obvious symptoms. Some may only display mild signs while their infection worsens internally. But watch out for these red flags:

• Excessive water consumption and frequent urination
• Loss of appetite and general lethargy
• Vaginal discharge (sometimes bloody or pus-filled)
• Depression and behavioral changes
• Pale gums and mucous membranes
• Fever or abnormally low body temperature
• Vomiting or diarrhea
• Distended, painful abdomen

“Even if your dog seems only mildly sick, if she’s unspayed and showing any of these signs, get her checked immediately,” Dr. Rebecca Greenstein, D.V.M., emphasizes. “Pyometra can progress rapidly from mild symptoms to life-threatening emergency.”

The Clock Is Ticking: How Pyometra Progresses

Early Stage: After heat cycle, hormonal changes thicken the uterine lining. This creates an environment where bacteria can flourish—sometimes endometrial hyperplasia develops first, where the uterine lining becomes abnormally thickened and remains that way.

Active Infection: Bacteria multiply, pus accumulates, and an abscess forms. Owners typically notice symptoms around this stage.

Rapid Deterioration: Without treatment, the infection spreads systemically. The dog’s circulatory system begins failing—heart strength diminishes, blood vessels dilate, and blood pressure crashes. Critical organs like the brain, heart, and kidneys become oxygen-starved.

Critical Phase: In closed pyometra (where the cervix doesn’t allow discharge), the uterus can rupture, causing life-threatening sepsis. In open pyometra, chronic infection develops. Left untreated, pyometra is typically fatal.

Diagnosing Pyometra: What Your Vet Will Do

Your veterinarian will start with a physical examination and reproductive history, then likely recommend:

• Complete blood count and chemistry profile
• Urinalysis and vaginal cytology
• Abdominal radiographs and ultrasound (usually conclusive)

The imaging tests are particularly important because they reveal whether the pyometra is open or closed—a critical distinction for treatment outcomes.

Treatment & The Cost Reality

Emergency spaying (ovariohysterectomy) is the standard treatment for pyometra in dogs. It’s curative but comes with a price tag. According to veterinary experts, total treatment costs typically range from $1,000 to $10,000, depending on:

• Diagnostic tests: $200–$3,000
• Surgical treatment: $500–$4,000
• Hospital stay: $200–$2,000 per day (critical cases may require multiple days)
• Medications (antibiotics, pain relief): $50–$400
• Follow-up care: $50–$350

Closed pyometra cases generally cost more because they require more intensive intervention and longer hospital stays.

The Prevention That Actually Works

Here’s what veterinarians agree on: early spaying is the most effective prevention. Dogs spayed early in life are significantly less likely to develop pyometra—plus, spaying prevents mammary cancer and other reproductive issues.

“Spaying surgically removes the uterus (and typically the ovaries), which is not only the treatment for many cases of pyometra but also the best means of preventing it in the first place,” says Dr. Greenstein.

Insurance & Life Expectancy

Whether pet insurance covers pyometra depends on your specific policy and whether diagnosis occurred before or after coverage began. Most policies do cover it as an emergency condition rather than pre-existing, but read your fine print carefully.

Your dog’s survival depends on several factors:

• Speed of diagnosis and treatment
• Whether complications developed
• The dog’s overall health and age
• Whether the pyometra is open or closed (closed is more dangerous)

With prompt surgical intervention, recovery is usually complete and excellent.

The Bottom Line

Pyometra symptoms in dogs demand immediate attention. If your unspayed female dog shows lethargy, excessive drinking, vaginal discharge, or behavioral changes—especially during or shortly after her heat cycle—don’t wait. Emergency veterinary care could be the difference between a full recovery and a fatal outcome. And if you haven’t already, talk to your vet about spaying as the best long-term protection.