An article by Dr. Mary Ann Sheller, Vale Park Animal Hospital
Pyometra (pyo: pus metra:uterus) is a serious infection of the uterus that occurs in unspayed female dogs. Most cases happen in middle or older aged dogs. The uterus fills with infected material, sometimes enlarging to 20 times its normal size.
Dogs which develop pyometra may not show symptoms in the early stages. Some will have a bloody or purulent vaginal discharge, others may not. Many will be very thirsty and have to urinate frequently. Some will be extremely sick…no appetite, sluggish, very depressed.
How is pyometra diagnosed?
Your veterinarian may suspect pyometra if your dog had a heat cycle in the past couple of months or if there is a vaginal discharge and she doesn’t feel well. Blood tests and xrays or ultrasound may be used to help confirm the diagnosis.
How is pyometra treated?
The most common treatment is removal of the uterus. This is essentially the same surgery as is done for a spay, but is more difficult and risky because the uterus is very diseased. Also, most patients are sick and older, so anesthesia and recovery are more worrisome. Patients may have to stay in the hospital for a day or two after surgery as the infection and temporary kidney damage resolves. Of course, antibiotics and pain medication will be given for several days to continue the treatment.
Are there alternative treatments?
In some patients, in which it is desired to have puppies in the future, a medical treatment consisting of antibiotics and hormonal treatments may be used. The treatment takes several days, and can only be attempted in dogs which are not severely ill. That particular dog will be at high risk of repeating the pyometra with every subsequent heat cycle. So it is important to have the desired litter on the very next heat and then spay her as soon as practical thereafter.
How can pyometra be prevented?
The best way is to spay your dog at a fairly young age (4 to 12 months depending on breed and other factors). Because the ovaries and part or all of the uterus are removed during a spay surgery, the dog will not have any heat cycles. No heat cycles, no chance of pyometra.