Pyometra is a medical emergency. If your unspayed female dog suddenly seems tired, stops eating, or develops unusual vaginal discharge after a heat cycle, don’t wait to see if she gets better. These can be signs of pyometra, a serious uterine infection that can become life-threatening without prompt treatment. 

Early veterinary care gives most dogs an excellent chance of recovery. If you have a female dog that hasn’t been fixed yet, you should know what causes pyometra, the symptoms to watch for, how it’s treated, and the best way to prevent it.

Key Points

• Pyometra is a serious bacterial infection of the uterus that affects unspayed female dogs, typically two weeks to two months after a heat cycle. It is a medical emergency that needs immediate vet care.

• Symptoms include vaginal discharge, lethargy, increased thirst, and swollen abdomen. 

• Spaying your dog is the most effective way to prevent pyometra and is also the primary treatment when infection occurs.

What is pyometra in dogs?

Pyometra is a bacterial infection of the uterus that affects unspayed female dogs. It's a serious and potentially life-threatening condition that needs prompt veterinary attention.

So how does it happen? Each time a dog in heat doesn't become pregnant, her uterine lining thickens. Over multiple heat cycles, this repeated thickening can lead to a condition called cystic endometrial hyperplasia, where cysts form in the uterine wall. These cysts create an ideal environment for bacteria to grow.

At the same time, high progesterone levels during and after heat prevent the uterus from contracting normally. This means bacteria – most commonly E. coli – can enter and thrive. Making matters worse, the uterus naturally lowers its white blood cell count during heat to protect sperm. While this helps with fertility, it leaves your pup more vulnerable to infection.

Pyometra typically develops two weeks to two months after a heat cycle. While it can affect younger dogs, it's most common in middle-aged to older unspayed females. In fact, about one in four older unneutered female dogs will develop pyometra at some point.

Open vs. closed pyometra

There are two types of pyometra: open pyometra and closed pyometra. The difference comes down to whether the cervix, the opening between the uterus and vagina, remains open or closes after the infection develops. 

In open pyometra, pus and other infected fluid can drain from the uterus through the vagina, making vaginal discharge one of the most noticeable signs. 

In closed pyometra, the cervix seals shut, trapping the infection inside the uterus. Because there’s no discharge to alert pet parents that something is wrong, closed pyometra is often harder to recognize and can become life-threatening more quickly as the uterus fills with infected material.

Closed pyometra is more dangerous because the infected material has nowhere to go. The uterus fills with pus, which can lead to rapid deterioration, toxin absorption, and a higher risk of the uterus rupturing. If you have an unspayed female dog, it's important to watch for any signs of illness after her heat cycle, even if you don't see discharge.

Signs of pyometra in dogs

Some dogs develop obvious vaginal discharge, while others become dangerously ill without any discharge at all. That’s why it’s important to recognize all the general signs of pyometra.

Here's what to watch for:

• Vaginal discharge (may be bloody, yellow, or pus-like – you might notice it where your dog has been sitting)

• Lethargy or listlessness

• Loss of appetite

• Increased thirst and urination

• Swollen or distended abdomen

• Vomiting

• Fever

• Collapse or shock (in severe cases)

Pyometra is a medical emergency. If your unspayed female dog shows any of these symptoms, especially after a recent heat cycle, call your vet or an emergency animal clinic right away.

Early treatment gives your pup the best chance at a full recovery. Don't wait to see if symptoms improve on their own.

How is pyometra diagnosed?

Your vet will start with a physical exam and ask about your dog's heat cycle history. From there, they'll typically run bloodwork and imaging tests to confirm the diagnosis.

Blood tests often show elevated white blood cell counts and increased globulin levels, which indicate infection. Your vet will also use ultrasound or X-rays to examine the uterus. Imaging helps confirm that the uterus is enlarged and filled with fluid, and it rules out pregnancy, which can look similar on initial examination.

How is pyometra treated?

The most effective treatment for pyometra is emergency surgery to remove the infected uterus and ovaries – a procedure called an ovariohysterectomy, or spay. While this is the same surgery used to spay healthy dogs, it's more complex when treating pyometra because the uterus is enlarged, fragile, and at risk of rupturing.

Your dog will likely need IV fluids to stabilize her before surgery, along with antibiotics to fight the infection. Hospitalization for monitoring is common, especially in severe cases. 

For valuable breeding dogs, some vets may consider medical treatment using prostaglandins (hormones that help the uterus contract and expel infection). In some countries, a drug called aglepristone may also be used. However, medical management is generally discouraged except for young, otherwise healthy dogs with open pyometra who are important to breeding programs.

Medical treatment has a lower success rate, can take about 48 hours to show results, and comes with side effects like restlessness, panting, vomiting, and abdominal pain. It's not recommended for critically ill dogs or those with closed pyometra.

How much does pyometra treatment cost?

Emergency pyometra surgery is significantly more expensive than a routine spay.

Pyometra surgery typically costs between $1,400 and $6,400, depending on your dog's size, how sick she is, and whether you're at a general practice or emergency clinic. By comparison, a routine spay usually runs $300 to $700.

How to prevent pyometra

The best way to prevent pyometra is to spay your dog before problems arise. Pyometra is largely preventable when a dog is spayed before infection develops, since an ovariohysterectomy removes the uterus and ovaries. In rare cases, stump pyometra can still occur if some uterine or ovarian tissue remains after surgery.

Spaying while your dog is healthy is a much simpler procedure than emergency surgery for pyometra. It's also less risky, less expensive, and has a shorter recovery time. 

FAQs

Can pyometra affect young dogs?

Yes, though it's less common. Pyometra typically affects middle-aged to older unspayed females, but younger dogs can develop it too.

What happens if pyometra is left untreated?

Without treatment, pyometra can be fatal. The infection can lead to sepsis (blood poisoning) as toxins spread through the body. In severe cases, the uterus can rupture, causing life-threatening peritonitis. Early treatment is critical.

What is the recovery time after pyometra surgery?

Recovery usually takes a few weeks, with strict rest for at least two weeks after surgery. 

Can pyometra be treated without surgery?

In some cases, yes, but it's not the preferred approach. Medical treatment with prostaglandins may be attempted for young, otherwise healthy breeding dogs with open pyometra. However, it has a lower success rate, takes longer to work, and isn't safe for critically ill dogs or closed pyometra cases.

Acting fast gives your dog the best outcome

It’s easy to dismiss a dog who’s sleeping more or skipping a meal, especially after a heat cycle. Trust your instincts; if something feels off, don’t wait to see if she improves. A quick trip to the veterinarian could make all the difference.