Pyometra is a life-threatening condition that occurs in un-neutered female dogs. Often, dogs will have a thick, sticky discharge from their vulva, but this is not always present. Most dogs will need surgery to treat the condition, but in some situations, it can be treated with intensive medical therapy. However, the dog will almost certainly develop another pyometra if they are not neutered.
life-threatening if left untreated.
Table of Content
Requires diagnosis by a veterinarian
Resolves within days or months with treatment
Treatable by a veterinarian
Prevention is possible
Transmission is not possible
Diagnosis requires examination, blood tests, and an ultrasound scan.
Middle-aged and older un-neutered female dogs of all breeds.
What Are the Signs & Types of Pyometra in Dogs
A pyometra is an infection within a dog’s womb. It usually occurs several weeks after they have been in heat, but can happen at any time, especially in older dogs who have irregular heats.
There are two different types of pyometra:
- An open pyometra is one where the cervix is open, and so this pus will drain out of the vulva, leading to a smelly discharge.
- A closed pyometra is one where the cervix is closed, so the pus is trapped within the wound, and no discharge is seen.
Both kinds of pyometra can lead to sepsis (bacteria in the blood), as the wall of the womb becomes weaker over time. However, it may happen more rapidly in a closed pyometra, where the pus is unable to drain out of the vulva and so the bacteria are trapped within the dog’s body.
Either type of pyometra can damage the lining of the womb, and eventually lead to it breaking and pus leaking into the dog’s abdomen. This causes septic peritonitis, which is a severe and difficult-to-treat condition.
Both open and closed pyometra will eventually be fatal if they are not treated by a veterinarian.
Common symptoms of pyometra include:
- Lethargy (quietness)
- Eating less, or not at all
- Drinking and urinating more than normal
- A painful belly
- A thick, sticky, foul-smelling discharge from the vulva (but only in open pyometra)
How is Pyometra Diagnosed?
The first step to diagnosing a pyometra is a thorough examination by a veterinarian. They will discuss your dog’s symptoms with you, and then check her over.
Some common findings with pyometra include:
- Pain in the belly
- Signs of sepsis (including a fast heart rate and changes to the gums)
- A discharge from the vulva (though this is not always present)
If your vet sees some of these signs, or if your dog’s symptoms are suspicious, then they will recommend running some more tests.
Dogs with pyometra will usually have a high white blood cell count. These are the infection-fighting cells, and the increased numbers mean that the body is trying to fight off a serious infection. Occasionally the white cell count may be low, as their body has been fighting for a while and is running out of these cells. This is more common with sepsis.
Your vet may also see:
- Low protein levels (common with serious infections)
- Raised kidney values – which may be due to dehydration, or damage to the kidneys from the infection
- Other signs of dehydration, such as a raised red blood cell count
The most common way to diagnose pyometra is by an ultrasound scan. This will show a large, fluid-filled womb. If the womb has ruptured, there may also be fluid free within the belly, which is more worrying.
There are other reasons why dogs can have fluid in their womb, so it is important to also examine a dog thoroughly and check the blood test results before diagnosing a pyometra.
If your vet does not have access to an ultrasound machine, they may do x-rays instead. They may also take a urine sample to analyze or send a sample of the pus to the lab to check which antibiotics are best to use.
In some cases, it may be necessary to proceed with treatment on the basis of the symptoms alone.
Causes of Pyometra in Dogs
Pyometras occur in female dogs (bitches) who have not been neutered. They are more common in middle-aged and older dogs but can happen at any age.
During a dog’s heat, their cervix (the passage which separates their womb from their vagina) is open. This means that it is possible for bacteria to travel up into the womb. The changes in hormone levels during a heat mean the dog’s immune system does not work as well as usual, and so these bacteria can start to grow. Over time this leads to the womb becoming filled with pus.
Pyometra can be prevented by neutering (also called spaying or sterilizing) dogs when they are young. The standard neutering operation removes a dog’s ovaries (ovariectomy), and sometimes her womb too (ovariohysterectomy). Even if the womb is not removed, taking away the ovaries will prevent pyometra, as without the hormones from the ovaries the cervix will remain closed, and no bacteria can enter.
“Ovary-sparing spays” involve removing the womb but leaving the ovaries intact. This will mean that the dog will still have heats but cannot get pregnant. However, it can leave them vulnerable to developing a “stump pyometra”, where the remnant of the womb becomes infected. Ovary-sparing spays also increase dogs’ risk of mammary (breast) and ovarian cancers and are not recommended by most veterinarians.
Best Treatment Options for Pyometra
There are two ways to treat dogs with pyometra: with medication, or with surgery. However, most dogs who are treated with medication will need surgery to be neutered once the pyometra has been treated, or it will come back during their next heat.
Surgery is the most common treatment for pyometra and involves removing the infected womb and ovaries (“ovariohysterectomy”). This is similar to the procedure used for neutering, but the infection means that the womb is more delicate and prone to bleeding, so the surgery is longer and more difficult than normal. Dogs will often need to stay in the clinic for a night or two after the surgery, and can then continue to recover after this at home.
It can take several weeks for dogs to get back to normal after pyometra surgery, but generally, their quality of life is as good or better than it was before the surgery. Occasionally, the dog’s kidneys may be damaged as a result of the pyometra infection, in which case they may need ongoing treatment for this.
It is possible to treat pyometra with medication alone in some dogs, but it is not straightforward and can be almost as costly as surgery. It is also not suitable for dogs whose womb has broken open and leaked fluid into their belly – this always requires surgical treatment.
Antibiotics are used to treat the infection, but these alone are not enough to get rid of the pyometra. These drugs can treat bacteria in the blood or the lining of the womb, but cannot get into the pus itself to kill those bacteria.
Hormone treatments must be given alongside the antibiotics to encourage the womb to shrink down and expel all the pus. There are various different protocols for doing this, depending on which drugs are available where you live. Your veterinarian can let you know if they have the right medication to attempt this kind of treatment.
Most dogs with pyometra are very unwell and will need to be admitted to a veterinary hospital to start their treatment. They will usually be put on a drip and treated with medications to help them feel better, including drugs to reduce fever, pain, and nausea. After a few days in the hospital, they can usually then finish their treatment at home, though they may need regular trips to the clinic for check-ups.
It is strongly recommended to neuter dogs who have had a pyometra that has been treated medically. There is a very high chance that they will develop another pyometra the next time they come into heat, and there is no proven way of preventing this from happening. Routine neutering is quicker and usually lower-risk than a pyometra surgery, but still involves risk.
Pyometra is a serious condition that is almost always fatal without intensive treatment from a veterinarian. Many dogs with pyometra will have a thick, sticky discharge from their vulva, but this is not always the case. If you have an unneutered female dog who seems to be unwell, you should get them checked by a veterinarian, especially if they have a discharge from their vulva.
Early signs of pyometra include lethargy (quietness), eating less and drinking more water. Some dogs may have discharge from their vulva, but this often comes later.
Pyometra usually develop over a few weeks, but dogs often show very few symptoms in the early stages. Once a dog appears to be sick from pyometra, there is a risk they could develop sepsis, which can lead to death within a hours.
When female dogs are in heat, their cervix (the passage between the vagina and the womb) opens slightly. This can allow bacteria to enter their womb, where they slowly grow and spread. When the infection starts to produce pus within the womb, then it is called a pyometra.
Most dogs will survive pyometra with treatment, though sadly some will pass away from sepsis or other complications. If pyometra is left untreated, it is almost always fatal.