I didn’t stay awake until midnight to watch the ball drop in Times Square. Nonetheless, I was still in my jammies when clients called late morning New Year’s Day. One good thing about being in practice so long on our little Island is that I know my clients pretty well. I know their names, their kids’ names, their pets’ names and histories, so when the owner told me Sandy wasn’t feeling well I immediately knew several pertinent facts. Sandy was a middle-aged large breed female dog … and she was not spayed.
“It started around Christmas,” her owner said. “She was drinking more than usual, and was incontinent once or twice.” I understood why they hadn’t been too concerned initially. Once before Sandy had experienced increased drinking and urine leaking that had turned out to be a minor urinary tract infection, nothing worrisome. “But last night her appetite was off,” he continued, “and this morning she vomited.”
Often with such symptoms, I might be comfortable giving telephone advice, making an appointment for the following day, and staying happily lounging in my jammies. But I knew those pertinent facts. Sandy was an unspayed, middle-aged, large breed, female dog. “Better come right down,“ I said.
Pyometra. A potentially life-threatening bacterial infection in which the uterus fills with pus and can actually rupture if treatment is delayed. The signs can be notoriously subtle for such a serious condition, initially consisting of nothing more than increased drinking and urination, but then progress to depression, loss of appetite, fever, abdominal distention, and vomiting. It occurs most frequently in dogs greater than seven years old with one study reporting almost one-fourth of all intact bitches may develop pyometra by the age of ten. Predisposed breeds include Bernese mountain dog, rottweiler, rough-coated collie, golden retriever, Leonberger, and Airedale terrier. A few smaller breeds also seem prone, including Cavalier King Charles, miniature Schnauzers, and Irish terriers, but any intact female dog is at risk.
The exact reason these severe uterine infections occur is incompletely understood. There are likely multiple factors involved. Most cases present within eight to 12 weeks after the dog has been in heat. Here’s why. When Sandy’s body gets ready for breeding, her cervix relaxes. This lets semen pass into her reproductive tract. It also can let bacteria in. Her body then suppresses white blood cell activity so as not to attack any incoming sperm, but this also reduces her resistance to infection. Finally, during this time, elevated progesterone levels lessen uterine contractions so as not to expel developing fetuses, but this also lessens her ability to expel other material. These changes are all designed to facilitate pregnancy, but when pregnancy does not occur, also create circumstances in which bacteria can invade the uterus and flourish. Eventually Sandy’s immune system recognizes that there is a problem and kicks in, sending legions of white blood cells (a.k.a. leukocytes) to try to fight off the infection. The uterus then fills with purulent material. In other words, pus.
So shouldn’t we see discharge from Sandy’s nether regions? Not always. In an “open cervix” pyometra, pus may indeed drain out, creating visible external discharge. These dogs are often not as sick as dogs with “closed cervix” pyometra. In “closed cervix” pyometra, after the heat is over, the cervix closes down tightly, shutting off any exit route for the purulent material, which then just collects inside the uterus. Dogs have a “bicornuate” uterus, meaning there are two long horns, each of which may become distended with copious amounts of pus.
When Sandy walked in the door, I immediately saw her belly was distended. Many diseases can cause a swollen tummy in a dog her size and age. I checked her gums. Nice and pink. Probably not a bleeding tumor of the spleen. I gingerly palpated her abdomen. She was not tense or distended in the manner typical of bloat. Pushing very gently, I could feel a mass consistent with an enlarged uterus. I dared not squeeze too hard for fear of rupturing it. The treatment of choice in most cases of pyometra is immediate ovariohysterectomy, i.e. get her spayed. There are medical techniques one can use to try to relax the cervix and contract the uterus to expel all that junk, thus saving reproductive potential, but there was no valid reason to consider this for Sandy. There were no plans to breed her, and there is a high risk of recurrence in cases treated medically.
I explained a definitive diagnosis would require radiographs and blood tests, but that would take time. The longer we waited to get her to a surgeon, and the more we manipulated her, the greater the risk of that pus-filled uterus rupturing, which is likely fatal. Many years ago when the standard of care in veterinary medicine was different, I did pyometra surgery on a golden retriever, removing a uterus with each horn swollen as big as my forearm. It is a tense event, trying to remove such an organ without disaster, and a long list of possible complications that can occur before, during, and after surgery, including peritonitis, uterine rupture, aspiration pneumonia, sepsis, acute respiratory distress syndrome, disseminated intravascular coagulation, and kidney failure, to name a few. Nowadays it is really the best medicine to refer these cases to board-certified surgeons with 24-hour care facilities and all the state-of-the-art bells and whistles. I suggested Sandy’s owners head immediately to Cape Cod Veterinary Specialists.
It felt odd, transferring Sandy so quickly without hard evidence such as x-rays confirming my diagnosis. I spent the day hoping I hadn’t sent them on a wild goose chase. But it walked like a duck and it quacked like a duck. Later that evening, the fax arrived confirming that, yup, it was a duck. She survived surgery to remove her infected uterus, and after a few days’ hospitalization, came home. A tough way for Sandy and her family to start the New Year, but a happy outcome.