Pyometra is a medical condition in which pus is accumulated in the uterus of a dog. It usually happens after the animal has gone through a heat cycle without becoming pregnant. Hormonal abnormalities result in the uterine lining becoming thick. When this happens, fluid begins to accumulate within the thickened walls, infection develops and the uterus fills with pus. In certain conditions, namely if the cervix is open, the pus will drain from the dog through the vagina and is an unpleasant, but not especially life-threatening concern. If the cervix is closed, however, the pus will be trapped inside the uterus and cannot drain outside the body. At this point, the infection rapidly becomes a threat to the dog's life.
Spotting pyometra early is the best way to successfully treat it. After each heat cycle during which your dog does not become pregnant, you should observe her for certain clinical signs that might indicate pyometra, such as draining pus, a sharply increased level of thirst and urination, and a swelling of the abdomen. Often these signs are accompanied by secondary symptoms like lethargy, a loss of appetite, and fever or dehydration.
If pyometra is suspected, a trip to the veterinarian for a confirmed diagnosis is in order. Your vet will monitor your dog for the above signs as well as take a blood sample for the sake of evaluating her white blood cell level. An evaluation of internal organ function and hormone levels, as well as an ultrasound and culture of the uterus might also be necessary is other signs produce unclear conclusions. In certain cases, a biopsy might need to be taken from your dog in order to rule out cancer.
After a diagnosis of pyometra has been confirmed, a multi-stage treatment plan will be enacted. At first, your dog will be placed on fluid therapy to overcome the effects of dehydration and become strong enough to withstand the next stages of treatment. Antibiotics are typically administered to combat the infection in the uterus and blood transfusions might need to be given as well, depending on the degree to which other organ function has been compromised. In the worst case scenarios, usually those that involve a closed cervix, your dog's uterus might have to be removed entirely. This is usually sufficient to save the dog's life, but of course will leave her sterile and in possible need of hormonal replacement therapy.
Nonsurgical treatment is possible, and is usually performed in cases where the cervix is open. If all pus is expelled and the infection is overcome, then the disease is considered to be bested. However, it's often best in these cases to have the dog spayed anyway, as the rate of recurrence of pyometra during the next heat cycle is incredibly high.
No matter which treatment option is used, the three week period following a bout of pyometra should be followed up with antibiotic therapy and a severe restriction of physical activity.