Pyometra is an infection of the uterus in dogs and cats making them extremely ill.

The purpose of this article is to make owners aware of a potential fatal problem, the earliest this is caught, the better the bitch's chance of survival.

Any unneutered bitch is at risk of developing a pyometra.
(Please don't all run out to get your bitches spayed young, let them mature first - read more here)

Although rare, a neutered bitch can develop a specific type of pyometra called a 'stump pyometra' – read more below.

There are two types, open, and closed, both can be fatal if not caught in time.

An open pyometra is when the womb entrance is open, meaning you are likely to see blood and pus coming from your dog’s vulva.

A closed pyometra is when the womb entrance is shut and you are unlikely to see any discharge. A closed pyometra is particularly dangerous because it is at risk of bursting.

Contrary to popular belief where it used to be believed that a 'Pyo' starts between 1 - 2 months after a bitch's season and was usually seen in bitch's over the age of 5, from experience, a 'Pyo' can be seen at any age, even on a first season, sometimes during a season, at the end of a season, and even after a bitch has been mated.

It is rare, but not uncommon to be bought a bitch to check for pregnancy to see no puppies, but the start of a pyo brewing, which is when she will be referred to a vet for further investigation. A blood test will often reveal an elevated white blood cell count, and the bitch may have a high temperature.

Some of the more common systems of a Pyo

  • Drinking more than usual
  • Vomiting
  • Pus leaking from vulva/vagina
  • Bloated abdomen (tummy)
  • Panting and weakness
  • High temperature
  • Lethargic
  • Not eating, or change in appetite
  • Weeing more than usual
  • Collapse

You should contact your vet for an urgent appointment if you notice your dog is off colour around the time of her season. A pyometra is an emergency and your dog/cat has the best chance of survival if they receive prompt treatment.

You know your dog best, if you are concerned it’s always best to contact your vet.

Just to give you an idea how paranoid I am about pyo's having had a vet mis diagnose one many years ago as a urine infection, and our bitch died, this is my experience in just one day.

Firstly, my own bitch, 8 years of age.
The season itself seemed heavier than normal, and 10 days into her season, she started to be picky with her food, noticeable because she normally has a voracious appetite. 11 days in she barely touched her supper, although she did appear hungry and had been running round the fields normally, it was very unlike her. The following day she seemed a little more lethargic, I had a feeling where this would be going and scanned her. See image below - nothing significant, the large black area is her bladder.

Knowing my own bitch and knew something must be going on, I contacted the vet. Unfortunately during COVID 19 you have to have a triage appointment over the telephone and I asked if I could take her in for bloods to check her white blood cell count. Results of bloods only showed a very slightly elevated white blood cell count at the top end of normal. Vet gave her an anti nausea injection and said if she didn't eat the next morning she may need more tests.

Next morning she almost turned green when I put her bowl down, so I called the vets again and was told they had a number of emergencies and it may need to wait until Monday. Not prepared to wait I scanned her again myself - see below.

A different scan from 24 hours previously, showing pockets of pus. Images were emailed to the vet and she was operated on within the hour.

It was confirmed to be a significant large closed pyo.

The very same day my bitch was having surgery, I was contacted by a veterinary nurse who had been furloughed. Her bitch had been scanned (not by me) and she thought she was carrying three puppies. At six weeks gestation she wasn't seeing any change in her, and no increase in weight, although she appeared to be fit and well.

Pyo's are not rare, but not something I see everyday, and I was shocked that this was almost the same scan I had done a few hours before on my own bitch. I referred the bitch to the clients vet, who thought because the bitch was well, it was puppies re absorbing.

Less than a week later, the bitch was in emergency surgery for a rather large pyo.

Please watch your bitch when in season and shortly afterwards for any change in behaviour, and at the very least, get her scanned to rule out a pyo if you are unsure.

A closed pyo comes on suddenly, and if it bursts, it is usually fatal and your bitch can be dead within hours.

Another case I saw in November 2022 - 27 days post mating
An ultrasound could literally save your dogs life


Read a breeders story HERE (pdf document)

Stump pyometra

When having a spay with keyhole surgery (laparoscopic spay), a small womb stump remains inside your dog. It’s rare, but possible, for an infection to develop inside that stump.