Pyometra

Pyometra is a condition in which the uterus fills with pus. It affects unspayed females, most often middle-aged and older cats, in the weeks after a heat. Hormonal changes alter the womb lining and let bacteria take hold. A cat that has been given hormone treatments is at higher risk.

In an open pyometra the cervix is open, so a thick discharge, often cream or bloody, drains from the vulva. A cat may also lick herself a lot. In a closed pyometra the pus stays inside, which makes the cat sicker and the signs less obvious. Look for drinking and urinating more, a poor appetite, lethargy, vomiting, a swollen belly and fever. The infection can spread into the blood and cause shock.

Pyometra is an emergency, so go to a vet at once. A vet will examine the cat, take blood samples and an ultrasound or X-ray, and usually advises a spay operation after stabilizing her with fluids and antibiotics. Some cases of open pyometra in valuable breeding cats may be managed with medicines, though recurrence is likely, and your vet will explain the risks. Preventing it is one of the main medical reasons to spay a cat that will not be bred.