Pyometra: A Preventable Disease in Female Pets

What is pyometra?
Pyometra describes a bacterial infection of the uterus (womb) and usually manifests with a pus-filled uterus. It means intact (unspayed) female pets are at the highest risk for this condition.

Pyometra makes your intact female pet very ill and can be life-threatening. It occurs because some of the toxins may leak into the affected pet’s bloodstream, causing widespread infection (sepsis). Pyometra must be treated quickly and vigorously to save a pet’s life.

When does pyometra commonly occur?
Pyometra usually occurs 4 to 6 weeks after a heat cycle in unspayed female dogs and cats.

How does pyometra happen?
During the heat cycle, the female body undergoes hormonal changes that alter the lining of the uterus to prepare for pregnancy. Unfortunately, the uterine changes also support invading bacteria to grow and reproduce which = infection. So if bacteria enter the uterus during estrus, this is bad news!

Where do pyometra-causing bacteria come from?
The bacteria are typically found in the areas of a pet’s intestines and vagina (For example E. coli).
Many of the infections are considered either from an ascending infection from the vagina, a concurrent urinary tract infection, or fecal contamination.

Which animals are susceptible to pyometra?
Any intact females are at risk. Typically, pyometra occurs in older dogs and cats because they have experienced many heat cycles. With each heat cycle, the hormonal effects on the uterus accumulate.

What are the common symptoms?

  • Lethargy (decreased energy levels)
  • Anorexia (refusing food)
  • Excessive water intake and/or excessive urination
  • Vomiting
  • Vaginal discharge containing blood and/or pus* (this may not occur in “closed” pyometra)

If you see any of these symptoms or are simply concerned, please contact us!

How is pyometra diagnosed?
Pyometra should be suspected in any unspayed female animal.
Confirmation of the condition involves:

  • Gathering the pet’s history (e.g. seeing if the pet has been drinking a lot of water and/or urinating
    more frequently)
  • Veterinarian conducting a physical examination, imaging (x-rays or ultrasound)

What are the treatment options for pyometra?
The optimal treatment involves spaying the affected dog or cat. Spaying (ovariohysterectomy) is surgical removal of the uterus and ovaries once the pet has been stabilized.

Because pyometra is a bacterial infection, the pet will be prescribed oral antibiotics and these should be continued for 7–10 days after surgery.

Occasionally breeding animals may be treated using medical therapy, but these treatments do not guarantee full recovery and pyometra recurrence is likely.

Spaying your dog or cat prevents pyometra and other conditions.
We welcome any questions regarding spaying or other preventive care!

Written by: Seneca Animal Clinic

Brooks, Wendy. “Pyometra in Dogs and Cats – Veterinary Partner.” Veterinary Partner, Veterinary Information Network, 2016 Retrieved from: https://veterinarypartner.vin.com/default.aspx?pid=19239&id=4951481.

Memon, Mushtaq A. “Pyometra in Small Animals.” Merck Veterinary Manual. Retrieved from: https://www.merckvetmanual.com/reproductive-system/reproductive-diseases-of-the-female-small-animal/

N.B. “Pyometra.” Small Animal Topics: Pyometra, American College of Veterinary Surgeons. Retrieved from: https://www.acvs.org/small-animal/pyometra.



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Last updated: December 16, 2020

Dear Clients,

Thank you for choosing Seneca Animal Clinic for your pets' veterinary needs. As we continue to adjust to the "new normal," we have implemented new protocols to keep you and our team safe.

It is still preferred that you stay in your vehicle while we bring your pet in for their appointment. However, as of August 14, 2020, we will be allowing one client to accompany their pet during their visit for urgent, new puppy/kitten, or euthanasia appointments.

Should you choose to come in with your pet, we kindly ask that you comply with the following protocols:

  • Our doors will remain locked. Please call us at 416.494.1109 upon your arrival.
  • Face coverings must be worn to enter the clinic.
  • Physical distance with staff and other clients while inside the building.
  • Use hand santizing station upon entry.
  • Continue the use of credit cards as the preferred payment method.
  • Continue with curbside pickup of food and medication (unless you have used our online store and are having your order delivered directly to your home). To place an order through our online store, visit our website and click on "Online Store".
  • If you wish to wait in your vehicle during the appointment, when you arrive, please remain outside the hospital and use your cell phone to call us. We will take a history of your pet's health and discuss any concerns. A staff member will then meet you outside to bring your pet into the hospital for an examination. The Veterinarian will call you to discuss the recommended treatment plan. After your appointment, a staff member will return your pet to you outside, and take care of any needed medications and payment.

    If you wish to connect with a veterinarian via message, phone or video, visit our website and follow the "Online Consultation" link.


    Have you welcomed a new furry family member to your home? We’d love to meet them! Visit our Must Know New Pet Owner Information page for useful resources and helpful recommendations for new pet owners.


    We are OPEN with the following hours:

    - Monday & Tuesday: 8:00 am - 6:30 pm
    - Wednesday: 8:00 am - 6:00 pm
    - Thursday: 8:00 am - 6:30 pm
    - Friday: 8:00 am - 6:00 pm
    - Saturday: 9:00 am - 1:00 pm
    - Sunday: CLOSED

    Thank you for your patience and understanding and we look forward to seeing you and your furry family members again!

    - Your dedicated team at Seneca Animal Clinic