I got the call at 7:00 AM Saturday. "I've been up all night with Fluffy. She's been vomiting and had a lot of fluid from the other end." With vomiting, I assumed she meant the dog had diarrhea. Fluffy arrived wearing a diaper. "How many times did she have diarrhea?" "I don't think it's coming from there." The lady couldn't bring herself to just say "vaginal discharge". That's what Fluffy had, though, and lots of it, and it was nasty. "She sleeps with us and I had to change the sheets." I can believe that.
Fluffy is almost eleven years old and was never spayed (ovariohysterectomy: the removal of both ovaries and the entire uterus). Fluffy's mom kept thinking that maybe sometime she'd like to raise a litter of puppies. She never got around to that, but then she was afraid to have Fluffy anesthetized (she still needs her teeth cleaned). Unfortunately, elderly intact female dogs develop female trouble. After all those heat cycles and no babies, the uterus finally began to nourish a nasty infection instead of the litter of pups it was designed for. Pus instead of pups.
Pyometra is pus in the uterus. Fortunately, Fluffy began discharging it, which made the diagnosis easy. Often the dog just has some non-specific "don't feel good". Classical signs (in addition to vaginal discharge) include vomiting, excessive water drinking and urination, abdominal swelling, and a high white blood cell count. Ultrasound imaging is a big help with diagnosing the ones that aren't discharging.
The dog's uterus is a Y-shaped, tubular organ -- two long tubes where the puppies would develop end-to-end like a string of sausages. It's interior (which we scientists call "the lumen") has an intimate connection with mama's bloodstream. It is across this same surface that the puppies derive their nutrition and get rid of their wastes. This means that whatever is in the middle of the uterus has the potential to cross over into the bloodstream and be spread throughout the dog's body. Not good.
Because it is a tubular organ, medical therapy is often ineffective. You can give antibiotics to kill the germs, and the medicine travels through the bloodstream and permeates the wall of the uterus, but not much will get into the lumen. You might be able to irrigate the uterus and remove a lot of the pus, but how can you be sure that you get into both tubes, and all the way to the end of the tubes? The answer is that you cannot do it, much less be sure you did it. Some dogs can be successfully treated by using a hormone-like compound called prostaglandin. This stuff causes the uterus to contract forcefully, expelling the pus. Treatment for several days with prostaglandin does cure the condition in some dogs. For many, it does not. The treatment is unpleasant (though not dangerous) and the dog's condition must be monitored for several weeks to be sure that the problem is in fact resolved.
For these reasons, the treatment of choice is always the complete removal of the uterus. If you are not raising puppies, it would be a lot easier for all concerned to have your dog spayed when she is young and healthy and you can plan for it, than to wait until she is old and sick and has to have emergency surgery with IV fluids, IV antibiotics, and intensive care.
I explained all this to Fluffy's mom, using color glossy pictures with circles and arrows and a paragraph on the back of each one, explaining what each one was. Mommy doesn't want a hysterectomy for Fluffy, and she's afraid for Fluffy to be anesthetized. Never mind that she's going to die unless we do the surgery today.
After the surgery was all over and Fluffy was recovering well, I apologized to the owner for "getting in her face". You see, when she protested the surgery, I went into "Dr.House" mode -- not nasty like House, but lots of graphic illustrations. "If you don't do the surgery, Fluffy will die. The infection wil spread through her bloodstream, shutting down her kidneys, damaging her heart, liver, going everywhere in her body. Once, about twenty-five years ago, I let someone talk me into medical treatment of a dog, but they didn't come back for follow-up. The treatment didn't work, and when they did come back, she had pus in her eyeballs! She didn't make it. You don't want the pus on your sheets, but it's okay to have it in her blood? We have to do the surgery today." [A true story, unfortunately]
All's well that ends well, but if you don't want to raise puppies, get the puppy-works taken out while the taking is good.