What it is
For some weeks after every season a bitch's womb is under the influence of hormones that prepare it for a possible pregnancy: the lining thickens and the womb's defences against bacteria weaken. With each season the lining changes a little more, which is why middle-aged and older bitches are more prone to pyometra, although a young bitch can develop it too.
When the cervix is open, the pus drains out and the owner notices a discharge. When it is closed, the pus builds up inside, the womb swells and there may be almost no outward sign, which makes this form especially treacherous. Substances released by the bacteria get into the blood and damage the kidneys and other organs, and an overfilled womb can rupture.
If your bitch is unspayed, keep a note of the dates of her seasons. If in the weeks after a season she starts drinking more, turns lethargic or refuses food, think of pyometra and don't wait for a discharge to appear.
Signs you may notice
- Pus-like or bloody discharge from the vulva
- Drinks and urinates a lot
- Lethargic and off food
- Vomiting
- Swollen belly
- Fever
The bitch turns lethargic, stops eating, drinks and urinates a lot, may vomit and run a fever, and her belly swells. A pus-like, bloody, foul-smelling discharge may come from the vulva, but there may be none at all if the cervix is closed. If you see these signs, don't wait: take her to a vet right away.
When to see a vet
If an unspayed bitch turns lethargic, drinks a lot, vomits or has a discharge from the vulva in the weeks after a season, she needs a vet immediately, day or night.
This is general information, not veterinary advice. For your own dog's health, tests and treatment, see a vet.