Pyometra in dogs: how to spot the early signs

What is pyometra in dogs?

Pyometra is a life-threatening womb infection in dogs that requires urgent treatment. It affects unneutered female dogs, usually within a few weeks of finishing their season. It is more common in older dogs but can be seen at any adult age.

The dog’s womb becomes infected with bacteria, which causes it to fill with pus. The infection can spread to other parts of the body and can be fatal if not diagnosed and treated quickly. In a UK study of dogs with pyometra, one in six didn’t survive. Dogs were also three times more likely to die from pyometra if they were over the age of six.

Early signs of pyometra in dogs include vaginal discharge, increased tiredness, intense thirst, weeing more and lack of appetite, but symptoms can vary and can be easy to miss. If you have even the slightest concern that your dog has pyometra you should contact your vet right away. The earlier she gets treated, the better her chances of recovery.

Key points

• Pyometra mainly affects older female dogs that haven't been spayed
• It’s caused by changes in the womb after each season (heat cycle)
• Look out for signs like tiredness, drinking lots of water, bad-smelling discharge, not wanting to move, vomiting, and not eating
• Treatment is usually surgery to remove the infected uterus and supportive care like antibiotics and fluids
• Spaying your dog prevents pyometra by removing the organs where the infection can develop

Read more: Dog neutering: Signs your dog needs to be neutered

What causes pyometra in dogs?

Pyometra is caused by bacteria, usually E. coli, entering your dog’s womb and causing infection. Each time your dog comes into season, she goes through hormonal changes which make it easier for the bacteria to enter the womb and embed in the thickened lining. The bacterial infection causes her womb to fill with pus, which can make her unwell, and also lead to infection spreading into other areas of the body. This can lead to blood poisoning (sepsis) and other serious conditions, and can eventually be fatal.

Any unneutered adult female dog can develop pyometra, but dogs over six years old are most at risk. The more seasons your dog goes through, the thicker the lining of the womb becomes, meaning that the likelihood of developing a womb infection increases with age.

Symptoms of pyometra in dogs

If your dog is suffering from pyometra you'll usually notice the first signs in the 2-8 weeks following her season. Keep an eye out for any symptoms around this time as they can be difficult to spot and may not be obvious until the infection has become more severe.

Symptoms of pyometra include:

• Tiredness or lethargy
• Increased thirst
• Urinating more frequently or with greater volume
• Bloody, brownish or creamy vaginal discharge, which can be smelly
• Reluctance to move or stand up
• Lack of appetite
• Vomiting 
• Swollen stomach (this could also be a sign of bloat - another emergency condition)
• Fever

Like most conditions or illnesses, your dog’s chances of survival are far greater if pyometra is treated early on. If you’re worried about your dog, especially if she’s just finished her season, contact your vet right away.

Pyometra treatment

Pyometra is a life-threatening condition, and urgent treatment is needed to give your dog the best chance of survival. 
The most common treatment option is surgery, to remove the infected uterus.. Depending on how unwell your dog is, the vet may advise stabilisation with fluid therapy and pain relief before surgery. After pyometra surgery your dog will probably have to stay in the clinic for a few days so the team can monitor her and treat any other symptoms. Most dogs make a full recovery after surgery, although there are risks when operating on a sick or older dog.

If surgery is not possible, medical treatment of pyometra is possible, although with this option there is the possibility that the condition will recur after the dog’s next season - which cannot happen after surgical treatment. 

Pyometra is extremely unlikely to go away without treatment so waiting for the infection to clear up by itself isn’t an option. The chances of success are far higher when pyometra is caught early, so it’s best not to delay. 

Preventing pyometra

Spaying your dog completely prevents the risk of pyometra. The risk is eliminated by removing the uterus and ovaries, as the infection can’t develop without them. 

Dogs spayed with laparoscopic, or keyhole, surgery are completely protected too. With this method the womb is left while the ovaries are removed. Without the ovaries your dog won’t go into season and experience the hormonal changes that can lead to development of the infection. So, whichever type of spay your dog has, they are protected from pyometra.

Can neutered dogs get pyometra?

There is a very rare condition called uterine stump pyometra which can affect neutered dogs if a fragment of the ovaries or uterus has been left during the spay surgery. While unlikely, if you spot signs of pyometra in your neutered dog, it’s best to err on the side of caution and speak to your vet if they display any unusual signs.

Academic research on pyometra

Chances of survival

Despite the critical nature of the condition, the survival rate is good if caught early and treated. A UK study which looked at 1040 cases of pyometra found one in six dogs died as a result of pyometra and were three times more likely to die from pyometra if they were over the age of six. Of the 659 cases that had surgery only 3.3% reported death as a postoperative complication. 

Need more info? 

For more help and advice on womb infection in dogs, the benefits of neutering or any other aspect of your dog’s welfare, have a chat with your local vet. Remember, members of Pet Health Club receive a significant discount on the cost of the neutering/spaying procedure.

Find your nearest vet using our find a vet page, or speak to a vet online using our video vets service.

Sources

Royal Veterinary College, 'Womb for improvement: Clinical Management and Outcomes of Pyometra in Bitches.' by Katelyn YJ Park et al.

'Canine Pyometra: A Short Review of Current Advances' by Rafael Gariglio Clark Xavier et al.

'Pyometra in Small Animals' by Ragnvi Hagman