Pyometra in dogs is common, but it's also 100 percent preventable.
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Veterinarians see many dire cases of pyometra in dogs that often require immediate emergency surgery. In fact, the American Society for the Prevention of Cruelty to Animals (ASPCA) says their vets see as many as three cases per week.

The good news is that this common medical issue, which specifically impacts unspayed female dogs, is almost 100 percent preventable. With veterinarian insight, we're exploring what causes pyometra, common symptoms of pyometra in dogs, treatment options, and prevention methods to make sure your pup stays healthy.

What is Pyometra in Dogs?

Every unspayed female dog goes into heat (estrus) throughout their life. This is a normal part of reproduction, but sometimes complications can occur—including pyometra.

"Pyometra is a uterine infection in unspayed female dogs," says Katie Pagan, DVM, and partner at Heart Paw in Baltimore, Md. "It is caused by a change in hormones following a heat cycle, and if left untreated can be deadly."

When a dog goes into heat, there's a surge of a hormone called progesterone. According to the Veterinary Centers of America (VCA), this triggers the formation of a thick uterine lining that's ideal for pregnancy. However, if the dog doesn't get pregnant over the course of several estrus cycles, then cysts can form within the uterus.

These cysts release fluids that can foster a bacteria-prone environment, which can ultimately lead to pyometra. The name itself is latin: "pyo" means "pus" and "metra" means "uterus."

Pagan says that roughly 25 percent of unspayed female dogs will develop this dangerous uterine infection, and that dogs in middle to late age are most likely to be affected. Many dogs can die from pyometra, which is why prevention and early intervention is crucial.

Signs and Symptoms of Pyometra

Pyometra in dogs can sometimes be difficult to spot, especially in the early stages of the infection. Signs will also vary depending on whether the dog's cervix is open or closed.

Abnormal discharge is one of the most common signs of open pyometra in dogs. "It can range from green and yellow to brown and red in color, and can appear different from discharge noted at the time of a heat cycle," Pagan says.

If the dog's cervix is closed, then this abnormal discharge may not be present. The VCA says to also be on the lookout for these common symptoms:

How to Treat Pyometra in Dogs

Dogs with pyometra can become ill very quickly, and it isn't something you should try to treat at home with antibacterial medications or by "waiting it out."

"If your dog is not spayed and you suspect signs of pyometra, it is imperative to take your dog to a veterinarian as soon as possible," Pagan urges. "Dogs will go downhill very quickly once they develop pyometra—usually within a day the symptoms emerge. The longer owners wait to bring their pet into the vet's office the worse the prognosis or outcome is."

In most cases, an emergency surgery to remove the dog's uterus is required. This is more complicated than a typical spay since the infection needs to be contained and therefore more expensive. Pyometra dog surgery costs typically range between $1000 and $1,500 according to the Northshore Humane Society.

There's a potential alternative treatment for pyometra in dogs that involves prostaglandins, which help lower the dog's progesterone levels. The VCA says this isn't considered as reliably effective as uterus removal and that may come with complications.

What's the Outlook for Dogs with Pyometra?

The good news is that pyometra in dogs is very treatable the earlier it is caught. However, it can sometimes be difficult to spot early signs and so it's not uncommon for veterinarians to see extreme cases by the time a dog has made their way to the vet's office.

As mentioned above, early cases of pyometra can often be treated by removing the uterus. Pagan says, "A typical recovery time is 14 days and most dogs do very well after the fact."

If left untreated, the infection can leak into the abdomen. This is referred to as a "septic abdomen" or "ruptured pyometra" and the outlook is not very good. Many dogs do end up passing, or need to be euthanized, if they have a case this extreme.

The bottom line is that dogs cannot live long with pyometra and need to be treated immediately.

How to Prevent Pyometra in Dogs

The best way to prevent pyometra is to have your dog spayed. This prevents them from going into heat, which prevents their uterine wall from thickening and developing the cysts that lead to infection.

"There is a very small chance that dogs can develop something called a 'stump pyometra' after being spayed, but this is a very rare complication," Pagan says. "A stump pyometra is an infection of the remaining uterine tissue if there is an excess left behind. Typically though, once a female dog is spayed we do not see any issues."

If your dog cannot be spayed, then being aware of the signs and being proactive about potential symptoms is your best line of defense against this common—sometimes deadly—infection.