March 2, 2020

General Medical Issues Surgery Wellness & Prevention

Pyometra (Infections of the Uterus) in Pets

by Aili V. Heintz, DVM

You may remember reading a previous blog post about spaying your female dog or cat. If you haven’t read that post, please do (and not just because I wrote it)! It has some good information in it regarding your pet’s health. In that post, I mentioned one risk of our animal friends not being spayed is the risk of a pyometra, which is an infection of the uterus.

Now, you may be thinking, “How bad could an infection be? It can be treated with medication.” Unfortunately, this is not usually the case with many pyometras. Pyometras can be life-threatening for your pet. Here are some things to know, including symptoms as well as treatments.

What is a pyometra?

A pyometra is defined as an infection of the uterus (a female’s internal reproductive tract), often caused by hormonal changes. Pyometras can occur in any intact (not spayed) female dog or cat. Most often, we see them 2-8 weeks after the pet’s most recent heat cycle due to the hormone changes that occur inside the body with heat cycle.

What are signs and symptoms of a pyometra?

  • Abnormal discharge from the vulva, often times yellow or brown and may have a strong odor 
  • Decreased appetite
  • Lethargy (seeming tired and less active)
  • Bloated belly
  • Depressed attitude/appearance
  • Vomiting
  • Diarrhea
  • Increased drinking and/or urination

Many times, pyometras can have very broad symptoms. For example, your pet may be more tired or not as hungry lately. This can make the infection difficult to diagnose. Sometimes there is no sign of infection, like pus, because the cervix can close and trap all that bad bacteria and pus inside the pet. Pyometras can be life-threatening because of this!

What do I do if I am worried that my dog has a pyometra?

Get to your vet or an emergency vet as soon as possible! The longer that you wait, the lower the chance that your pet will recover. Remember that this can be fatal in pets if it is not addressed soon enough.

What will my vet do to know if it is a pyometra?

It will depend on what your vet finds during her examination. Often times, we do bloodwork to help look for signs of elevated white blood cells that can indicate an infection. Bloodwork also reveals other abnormalities that could be causing your pet’s symptoms. We may do X-rays to look for an enlarged or distended uterus. In some cases, veterinarians use ultrasound to look for problems with your pet’s uterus/reproductive tract. Not all veterinary offices have ultrasound equipment, so you may be referred to a specialist’s office for this diagnostic test. 

Is there a treatment for this?


The best treatment option for pyometra is usually an emergency spay surgery. Please keep in mind, an animal in the later stages of this infection may be very ill and may not be able to withstand the anesthesia required for the surgery. Often times, the animal will need IV fluids to help rehydrate her body and antibiotics to treat the infection.

If your pet used for breeding and you prefer not to spay her, discuss the options with your veterinarian. There may be other treatments, but depending on the condition of your pet, they may not be successful. This means that by delaying surgery, you could put your pet at risk for other complications or death.

What if I choose to do nothing?

The chance of your pet recovering without treatment or surgery is extremely low. In cases where the cervix may be closed and the pus is trapped inside, the uterus may actually rupture. If the uterus bursts open inside your pet, it will release a large number of bacteria inside your pet and will lead to her death. If for some reason treatment is not an option, you may need to choose humane euthanasia to prevent your pet from suffering.  

What can I do to prevent a pyometra for my pet?

The best way to prevent a pyometra is to spay your pet. Spaying removes the ovaries, the uterus, and the hormones that cause pyometras to happen. And as an added bonus…spaying your pet when she isn’t sick is much safer for her and much less expensive for you!

Pyometras can be scary for both you and your pet, especially since the symptoms are common to so many other illnesses. Spay her before this problem happens to avoid the pain and expense altogether. If you have questions about spaying or pyometras, discuss your concerns with your veterinarian. As always, prevention of this horrible infection is the easiest and safest thing to do for your pet and her health!

Dr. Aili V. Heintz, countrycare animal complex
Dr. Heintz is a small and exotic animal veterinarian at Countrycare Animal Complex in Green Bay, WI. She earned her Doctor of Veterinary Medicine from the University of Illinois – Urbana/Champaign. Her passion is helping all animals, whether furry, scaly, or feathered, lead long and healthy lives.