By Dial A Vet Veterinary Team
Pyometra is not a "wait until Monday" infection. It is a uterus full of pus that can rupture into the abdomen or seed the bloodstream with bacteria. Intact queens (female cats that still cycle) are the patients. Many owners have never heard the word until their cat starts drinking gallons, vomiting and leaking foul discharge after a heat. Desexing prevents this disease. Once pyometra is present, surgery is usually the definitive fix.
Key takeaways
- Pyometra typically appears in middle-aged to older intact females, often a few weeks after oestrus.
- Open pyometra leaks pus through the vulva. Closed pyometra traps pus inside and can look subtler until the cat is very sick.
- Fever, lethargy, vomiting, huge thirst and a swollen belly are alarms.
- Emergency ovariohysterectomy (spay removing ovaries and uterus) is the usual treatment after stabilisation.
- Related: pyometra in dogs, diabetes in cats (thirst overlap).
Why it happens
After a heat cycle, progesterone prepares the uterus for pregnancy. In some cats the uterine lining becomes an ideal culture medium for bacteria ascending from the vagina. Hormonal influence plus bacteria equals a dangerous abscessed organ. Medical "antibiotics alone" approaches are unreliable and risky compared with surgery in most companion cats.
Signs to watch for
- Vulval discharge that may be bloody, creamy or foul (open form)
- Licking the rear excessively
- Drinking and urinating much more
- Reduced appetite, vomiting, hiding
- Distended, painful abdomen
- Fever or paradoxically low temperature in septic cats
- Collapse in advanced cases
Closed pyometra may show little discharge. Do not wait for pus on the floor tiles.
When it is an emergency
Any intact female with post-heat illness, abdominal pain, ongoing discharge, marked thirst with lethargy, or suspected uterine infection needs urgent veterinary care. Suspected rupture (sudden worsening, shock) is a critical emergency.
How vets diagnose pyometra
Exam, bloodwork and ultrasound or X-rays usually confirm a fluid-filled uterus. Vets also check for kidney injury, dehydration and sepsis risk. Differential diagnoses include pregnancy, urinary infection and diabetes. Imaging separates them.
Treatment overview
Most cats are stabilised with fluids and supportive care, then proceed to ovariohysterectomy as soon as they are safe for anaesthesia. Antibiotics support the plan. Delaying surgery to "try medicine first" can allow rupture. Rare medical protocols exist for valuable breeding animals under specialist guidance. They are not the default for pet queens and still carry recurrence risk.
Aftercare includes pain relief, rest, wound checks and preventing the cat from licking sutures. Appetite should return as sepsis clears. Spaying also ends future pyometra risk.
Prevention
Desexing before or after the first seasons, timed with your vet's advice, is the prevention story. If you intentionally breed, watch carefully in the weeks after heats and book promptly for any illness.
Breeding households
If you intentionally leave queens entire for breeding programs, track heats on a calendar and diary any post-season illness. Budget for emergency surgery risk as part of breeding costs. Early desexing of pet kittens that will not enter a managed breeding plan remains the simplest prevention conversation for most Australian households.
Differentiating from other thirsty cats
Diabetes and kidney disease also cause big thirst. Intact status plus a recent heat plus uterine enlargement on ultrasound points to pyometra specifically. Do not start insulin for "suspected diabetes" based on thirst alone in an entire queen until pyometra is ruled out. Bring a urine sample if you can collect one safely on the way to clinic.
Pain and nursing after surgery
Queens may hide pain. Watch for hunched posture, litter tray avoidance and hissing when picked up. Give pain medicines on schedule rather than waiting for obvious crying. Soft litter or shredded paper may be advised temporarily so granules do not stick to the incision. Separate rough playmates until the clinic clears normal activity.
FAQ
Can a cat that had one litter still get pyometra?
Yes. Intact females remain at risk later in life.
Is discharge after mating normal?
Small amounts can occur. Foul, ongoing pus with illness is not normal. Call your vet.
Will antibiotics alone fix it?
Rarely a complete, safe solution for pet cats. Surgery is the standard of care in most cases.
Can desexed cats get pyometra?
If the uterus was fully removed, classic pyometra should not occur. Stump complications are uncommon but possible if tissue remains. Ask your vet if a previous surgery was incomplete.
Talk with a vet
If your entire queen seems unwell after a heat, contact a Dial A Vet veterinarian for urgent triage. Book a Dial A Vet consult.
References
- Merck Veterinary Manual. Pyometra in cats.
- Australian Veterinary Association. Companion animal desexing and pyometra education.
- WSAVA. Reproduction and emergency surgery resources.
Disclaimer: Educational only. This page does not replace an examination or advice from your own veterinarian. If you are worried about your pet right now, contact your local vet or nearest emergency animal hospital.