FR
EN
What is feline pyometra?
Under the influence of hormones (primarily progesterone), the uterus of an unspayed cat can become the site of a severe bacterial infection: pus accumulates inside, causing inflammation and systemic toxicity. Although less common in cats than in dogs, feline pyometra is equally dangerous.
Two forms to distinguish
The distinction matters clinically: an open-cervix form presents earlier; a closed-cervix form is often more severe because the infection stays trapped inside.
Pus can drain out
- Purulent vulvar discharge, sometimes bloody
- Unpleasant odor may be noticeable
- Diagnosis is often easier: the discharge alerts the owner
- Still an emergency: infection is active and the uterus remains distended
Pus is trapped inside
- No visible vulvar discharge
- Distended abdomen, painful on palpation
- High risk of uterine rupture and peritonitis
- More guarded prognosis: infection is invisible, often diagnosed later
Why does this happen?
Unlike dogs, cats usually ovulate only after mating: this is called 'induced ovulation', and only then does progesterone rise and prepare the uterus for a pregnancy. That is why pyometra is less common in cats. But when this progesterone exposure repeats (repeated matings, spontaneous ovulations, and above all hormonal contraceptives), the uterine lining thickens excessively (cystic endometrial hyperplasia) and retains secretions: an ideal environment for bacteria (often Escherichia coli). The risk increases with age and the number of ovulatory cycles.
Signs and symptoms
Symptoms evolve depending on the form (open or closed cervix) and how quickly the infection progresses. Here is how to recognize them, from subtle early signals to a clear emergency.
Early stage
- Drop in energy; less active or more withdrawn
- Reduced appetite
- Dull coat, neglected grooming
- Thirst and urination sometimes increased (less consistent than in dogs)
- Slightly elevated or fluctuating temperature
Intermediate stage
- Thick, yellowish or reddish vulvar discharge (open cervix)
- Distended, tender abdomen on palpation (closed cervix)
- Vomiting, possible diarrhea
- More pronounced lethargy
- Visible weight loss
Advanced stage
- Severe depression, collapse
- Marked dehydration
- Persistent foul odor around the vulva
- Very little or no urine output (kidney failure)
- Pale gums, rapid breathing (septic shock)
- Inability to stand or walk
These signs: go to the vet immediately
Pyometra can progress to septic shock within hours. Every hour matters. Contact your veterinarian or an emergency clinic right away if you observe any of the following:
- Abundant vulvar discharge, foul-smelling or greenish/brown in color
- Visibly distended and painful abdomen; the cat refuses to be touched
- Repeated vomiting or uncontrollable diarrhea
- Pale or whitish gums, rapid heart rate, labored or rapid breathing
- Inability to get up, collapse, blank stare
- No urine output for more than 12 hours despite normal or increased water intake
How is the diagnosis made?
The diagnosis of pyometra is based on a combination of clinical history, physical examination, and complementary tests. The earlier it is made, the better the cat's chances.
Clinical signs and history
Unspayed female, age, last heat or mating, hormonal contraceptives, vulvar discharge: the veterinarian builds the picture. In a mature unspayed cat, the combination of lethargy, reduced appetite and vulvar discharge (or a distended abdomen with no visible discharge) should always raise suspicion of pyometra; increased thirst may be present but is less consistent than in dogs.
Physical examination
Abdominal palpation to assess uterine size and tenderness. Examination of mucous membranes (gums), heart rate, and temperature to detect shock or sepsis.
Blood work
Complete blood count: leukocytosis (significant increase in white blood cells) is typically found. Biochemistry panel to assess kidney and liver function, often impaired by the infection.
Urinalysis
Assesses kidney function and detects proteinuria or concurrent urinary infection. Low urine specific gravity often indicates the kidneys are already being challenged by bacterial toxins.
Abdominal ultrasound
The reference exam: directly visualizes the fluid-filled (pus) uterus, evaluates wall thickness, and measures the extent of distension. Essential before any surgical decision.
Treatment options
Surgery is the treatment of choice in the vast majority of cases. Medical treatment is only considered in very specific situations. Here is why.
Supportive care (in all cases)
- IV fluid therapy to correct dehydration and support circulation
- Broad-spectrum antibiotics, adjusted based on bacterial culture when available
- Analgesics if pain is confirmed
- Close monitoring of kidney function
What to expect?
The prognosis depends above all on the speed of intervention and the cat's general condition at the time of presentation.
Post-surgical recovery is generally well tolerated. Most cats return to normal life within 10 to 14 days. Following post-operative care, including wound monitoring and completing the full antibiotic course, is essential.
Management, recovery, and prevention
After surgery: the recovery period
- Give all prescribed medications to completion, even if the cat seems well
- Inspect the incision site daily: excessive redness, swelling, discharge, or opening must be reported
- Limit jumping and intense activity for 10 to 14 days (stairs, high furniture)
- Keep the litter box clean and easily accessible without effort
- Encourage hydration: fresh water at all times; water from a fountain if the cat refuses to drink
- Offer appealing food, slightly warmed if partial anorexia persists
- Attend all scheduled follow-up appointments (day 7 minimum)
Signs to monitor after surgery
- Fever (cat feels hot, is prostrate, refuses to eat)
- Open, bleeding, or weeping wound
- Persistent vomiting or diarrhea more than 24 hours after surgery
- No urine output or very dark urine
What to avoid
- Self-medicating with antibiotics (leftover prescriptions): this can mask the signs, delay diagnosis, and complicate surgery
- Waiting for the signs to worsen: every hour counts, especially with a closed-cervix pyometra
- Hormonal contraceptives (to suppress heat) in an unspayed cat, unless specifically prescribed: they expose the uterus to progesterone and promote pyometra
- Stopping prescribed medications before the end of the course because the cat seems better
The best protection: spaying
Spaying (ovariohysterectomy or ovariectomy), performed before the first heat or early in adult life, is the only fully reliable prevention against pyometra. Done young, it also greatly reduces the risk of mammary tumors (in cats, these tumors are malignant in roughly 85 to 90% of cases, which is why early spaying matters) and eliminates other hormone-dependent conditions. If your cat is unspayed and not intended for breeding, spaying is the single most protective decision you can make for her long-term health.
Frequently asked questions
My cat has vaginal discharge: does it definitely mean pyometra?
My cat is young (2 or 3 years old): can she get pyometra?
Do hormonal contraceptives increase the risk in cats?
My cat was treated medically for pyometra. Can she have kittens afterward?
Why are the kidneys often affected by pyometra?
Is spaying still useful if my cat has already had pyometra?
How much does pyometra surgery cost?
See also
This guide is provided for informational and educational purposes only. It does not constitute veterinary medical advice and is not a substitute for a consultation with a qualified veterinarian. Every animal is unique and their health must be evaluated individually. If you have concerns about your pet's health, contact our clinic or consult a veterinarian promptly.