Pyometra In The Canine

Pyometra In The Dog
by T. J. Dunn, Jr. DVM
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[See a dog spay... See a dog neuter...]

Pyometra in the dog is a very serious condition! Before we look at what pyometra is, let's review the best way to avoid pyometra... and that is spaying. Pyometra means pus in the uterine cavity; if a pet is spayed the uterus and ovaries are removed so there no chance of pyometra developing. (There is no such thing as SPADE or SPADED, the correct terms are SPAY or SPAYED). It is major intra-abdominal surgery performed under general anesthesia. If it isn't done precisely and in a sterile environment the outcome can be disastrous. During my career I've never considered any spay "routine"; every one is different and each presents a challenge.

Usually the procedure is done prior to the first estrus (heat) cycle and having it done at this time greatly lessens the dog's chances for later development of mammary gland cancer. Some dog owners, for various reasons, want their dog to have one estrus cycle or even one litter of pups before she's spayed. And some pet owners do not want their pet to undergo any surgery. Personal choices do come with responsibility, too, so it is best to be sure there are homes waiting for any planned pregnancies.

Probably 80% of dog spays are done prior to the first heat cycle. The other 20% will go into their first heat around 9 -12 months of age and then about every 6 to 7 months thereafter until about 9 or 10 years of age. An unspayed dog does incur some special health risks throughout her life. Mammary cancer, unwanted pregnancies, ovarian cysts and cancer, difficult pregnancies... and fights with wandering male dogs who seem to appear from nowhere during the three week estrus cycle are a few troubles that readily come to mind. Cats generally go into their first heat cycle at 6 to 7 months of age. It seems like they go back into heat whenever they feel like it after that! Technically, cats are seasonally polyestrous... which means they go in and out of heat a few times during certain seasons of the year.

Here's a real nasty problem . . . pyometra. The term means pus in the uterus. Any time a veterinarian is presented with a dog or cat suffering from pyometra the condition is considered serious and immediate surgery is nearly always indicated. This pus formation in the uterus results from infection, hormone imbalance or mucous buildup inside the uterus. Most dogs and cats suffering from pyometra are presented because of loss of energy, increased thirst and poor appetite. Plus a good tip-off would be a foul smelling, purulent (means pus) vaginal discharge. Most of the cases of pyometra I've seen in dogs occurred about six weeks after the bitch's last heat cycle. They may not look it on the outside, but on the inside these dogs are really sick! If that swollen, enlarged uterus happens to rupture internally, the dog will rapidly go into endotoxic shock and whatever the veterinarian does may not be enough to save the dog.

Normally, even in a large dog, the uterine horns aren't much thicker than a pencil. See the photo on the right for normal anatomy... click it to enlarge. When pyometra is present the uterus looks and feels more like a stuffed venison sausage. I've removed eight-pound uteruses that should have weighed no more than eight ounces!

For whatever reason, if your female dog or cat hasn't been spayed be alert for pyometra. The condition is more probable in females eight years or older and who experience infrequent or irregular heat cycles or episodes of false pregnancy. Poor appetite, increased thirst, poor stamina and vaginal discharge are cardinal signs. And some patients' white blood cell count can go from a normal of 9,000 all the way up to 75,000. X-rays often reveal two large sausage-like structures in the abdomen. It's time for surgery! These patients should almost always be operated on right now, not after work, not in the morning, not after a few days of antibiotics "to build her up."

The surgery is not a minor procedure. A patient with a uterus swollen with a foul and putrid soup, is simply carrying a bucket of poison that would eventually kill the cat or dog. Many of these patients require I.V. fluid therapy, antibiotics and nutritional support post-operatively. These pyometra patients, once recovered, act like puppies once their near death experience is over!