Pyometra - another reason to spay your pet!

We all know the benefit of spaying our female pets to prevent unwanted heat cycles and litters. But did you know that spaying also prevents a life-threatening disease known as pyometra? The term pyometra is derived from Latin pyo meaning pus and metra meaning uterus. The disease occurs when the uterus becomes infected resulting in an abscessed pus filled uterus. The infection causes bacteria and toxins to leak into the bloodstream. Without treatment death is inevitable from the resulting septicemia and toxemia.

The typical patient is a middle-aged to older female dog that has undergone a heat cycle within the past 2 months. The heat cycle results in fluid accumulating inside the uterus; bacteria then ascend from the vagina and the uterus becomes infected and ultimately pus filled. The patient usually loses her appetite while drinking an excessive amount of water. As the disease progresses, she becomes weakened and lethargic and usually begins vomiting. The patient may have a discharge from her vagina if her cervix is open and allows some of the fluid to drain. However, many patients have a closed cervix and no discharge is seen. These patients tend to be sicker since the toxins and pus have no outlet.

The diagnosis is best made by ultrasound examination which quickly confirms the presence of a fluid filled uterus. Without ultrasound the diagnosis can be quite challenging and may require exploratory surgery.

Treatment requires immediate surgery to remove the uterus and ovaries. The surgery can be very challenging, especially if the patient is toxic. Aggressive antibiotic and IV fluid therapy are also essential to resolve the infection and reverse the toxic damages to the body.

Due to the complexity of the surgery and additional supportive therapy, the pyometra surgery typically costs 4-5 times as much as a routine spay surgery.















This is a picture of a normal uterus of a 55 pound dog following a routine spay surgery. Note the size of the uterus in relation to the ruler & surgical instruments.














This is a picture of a uterus filled with fluid which has not yet become infected. This patient would have developed a pyometra in the near future if the owner had delayed spaying much longer.
















This is an ultrasound image showing a section of the uterus filled with fluid. The patient was taken to surgery and the uterus was removed.

This is the pyometra uterus that was surgically removed. Note the size of the uterus in relation to the surgical instruments. This patient was also 55 pounds. As expected, the fluid filling the uterus was pus.

Spaying represents complete prevention of this disease and cannot be over-emphasized. Often owners plan to breed their pet or are undecided, time passes, and they fear she is too old to be spayed. A female dog or cat can benefit from spaying at any age. The best approach is to figure that pyometra will eventually occur if a female pet is left unspayed; any perceived risks of surgery are greatly out-weighed by the risk of pyometra.