Overview of Canine Pyometra

Pyometra is the medical term used to describe an infected uterus. This infection can be open (draining pus from the vagina) or closed (pus is contained in the uterus by a closed cervix).

Pyometra can be a life threatening infection and may even require emergency surgery. A closed pyometra is more of an emergency than an open pyometra, since there is no drainage of pus in a closed pyometra. If left untreated, dogs become very ill and some may not survive. With early treatment, about 90 percent of affected dogs recover.

Since pyometra is an infection of the uterus, all unspayed dogs are susceptible. Usually, pyometra occurs within eight weeks of the dog’s last heat cycle due to increased levels of the hormone progesterone.

What to Watch For

Signs of pyometra in dogs may include: 

  • Vaginal discharge
  • Lethargy
  • Lack of appetite
  • Depression
  • Vomiting
  • Diarrhea
  • Drinking excessive amounts of water and urinating often
  • Diagnosis of Pyometra in Dogs

    In order to diagnose pyometra, your veterinarian will begin by asking you many questions to develop a complete history of the course of the disease. These questions may include:

  • When did the problem start?
  • When was your dog’s last heat cycle?
  • Have your pet’s drinking and urination habits changed recently?
  • Has there been any vaginal discharge and what did it look like?
  • What have your dog’s appetite and demeanor been like?
  • After obtaining a medical history, your veterinarian will examine your dog completely, including checking for a fever, palpating her abdomen, and performing a vaginal exam to check for tumors or other abnormalities.

    Blood tests are often submitted to look for abnormal white cell counts, which could indicate the presence of an infection and abnormalities in kidney function, which can develop secondary to a pyometra. Urine tests are also submitted to check the patient’s kidney function and look for a urinary tract infection.

    X-rays (radiographs) of the abdomen are taken to look for a fluid filled uterus, which is suggestive of a pyometra and an abdominal ultrasound to look for a fluid filled uterus and also to rule out an early pregnancy.

    Treatment of Pyometra in Dogs

    The ideal treatment for pyometra is an ovariohysterectomy (spay). Before surgery is performed, some patients may require emergency stabilization in the form of intravenous fluids and antibiotics, especially if septic shock or kidney failure have developed.

    Medical therapy alone is not recommended. There is a high recurrence rate with hormonal treatment, and there is a two-day delay in its effectiveness, which could risk the patient’s life.

    Home Care and Prevention

    There isn’t any home care for pyometra. Once treated, monitor your dog’s appetite, demeanor, drinking and urination habits so that you will notice any changes. If surgery was performed, monitor the incision for normal healing.

    The only way to prevent pyometra is to have your dog spayed.

    In-depth Information on Pyometra in Dogs

    Pyometra describes a pus filled, infected uterus. It is a life threatening condition that requires emergency stabilization and surgery for treatment. Intact (non-spayed) female dogs are at risk for developing pyometra.

    Pyometra usually occurs after a heat cycle in which the dog did not become pregnant. Typically, pyometra most often develops around eight weeks following the heat cycle. It should not be confused with metritis, which is a uterine infection that develops following the birth of puppies.

    Pyometra can be defined as open (draining pus out of the vagina through an open cervix) or closed (pus is trapped in the uterus due to a closed cervix). Closed pyometras are more dangerous, since the infection is trapped in the dog’s body.

    The infection is not only life threatening on its own, but it can also cause kidney failure through bacterial toxins. If treated quickly with surgery and antibiotics, approximately 90 percent of dogs affected with pyometra will survive.


    Diagnosis In-depth of Pyometra in Dogs

  • History. Your veterinarian will ask specific questions about your pet’s appetite, activity level and attitude. Animals with pyometra are often depressed and lethargic. They may vomit or have diarrhea and often show no interest in food.

    Because of the secondary effects on the kidneys, pyometra can also cause increased drinking and urination. So, your veterinarian may ask about any changes in your pet’s drinking or urination habits. You may also be asked if you have noticed any vaginal discharge from your pet. Open pyometras produce a pus-like vaginal discharge. Closed pyometras do not drain pus from the vagina.

  • Physical exam. Your veterinarian will perform a complete physical exam. This will include palpation of your pet’s abdomen for an enlarged uterus and examination of your pet’s vagina for discharge, tumors, or other abnormalities. Your veterinarian will also take your dog’s temperature to check for a fever.
  • Radiographs (X-rays). X-rays are taken of your pet’s abdomen to identify an enlarged, fluid-filled uterus. This finding, taken with your pet’s other signs, can suggest a diagnosis of pyometra.
  • Ultrasound. Abdominal ultrasound is another way to identify an enlarged, fluid filled uterus and to rule out an early pregnancy.
  • Blood and urine tests. Blood tests are submitted to evaluate the white blood cell count, which is usually elevated with an infection. The number of red blood cells is checked to look for anemia.

    The function of the kidneys is evaluated through testing the blood as well as the urine. The urine is also tested for the presence of bacterial infection. The levels of electrolytes in the body are checked to determine the patient’s hydration status and to help guide the type of fluid therapy.

  • Therapy In-depth of Pyometra in Dogs

  • Emergency stabilization. Initially, your pet is given intravenous fluids and antibiotics and treated for shock and dehydration, if necessary.
  • Surgical management. The treatment of choice is an ovariohysterectomy (spay). The pet is anesthetized and the ovaries and uterus are carefully removed. This treatment is curative and prevents recurrence.
  • Medical management. This method of treatment involves the injection of hormones, called prostaglandins, to change the environment in the uterus. Antibiotics are also given. Medical treatment of pyometra is not recommended.

    It takes two days for the hormone injections to take effect, during which the pet could die of infection or kidney failure. There is also a high incidence of recurrence of pyometra with medical management. Furthermore, not all pets respond to this therapy and require life-saving surgery after this therapy has failed.

  • Spaying an animal that has pyometra remains the best standard of care. This therapeutic course will unfortunately render a potentially valuable breeding animal sterile but it will likely save her life.
  • Follow-up Care for Dogs with Pyometra

    Optimal treatment for your dog requires a combination of home and professional veterinary care. Follow-up can be critical, especially if your dog does not rapidly improve.

  • Administer all prescribed medications as directed. Alert your veterinarian if you are experiencing problems treating your dog. 
  • Be familiar with your pet’s appetite, attitude and activity level. It can be very helpful if you notice subtle changes in your pet’s behavior, eating, drinking or urination habits. The more you are aware of what is “normal” for your pet, the quicker you will be able to pick up on something going wrong. As with most diseases, early detection and intervention is best.
  • Be familiar with your dog’s body. If you notice any vaginal discharge or other signs associated with pyometra, contact your veterinarian.
  • If you have no plans to breed your pet, have her spayed as early as your veterinarian recommends.