Case of the Month - December 2010

"Daisy"

                                 By, Dr. Robin Kramer

 One morning in the middle of September, an 8 year old Beagle-Terrier mix named “Daisy” was dropped off by her owners for a dental cleaning.  Like many dogs and cats her age, Daisy had significant dental disease, including tartar visible on her teeth and inflammation of the gums called gingivitis.  We pointed out these abnormalities during a routine physical exam. Because dental disease is painful, and can lead to diseases of other organ systems including the heart and liver, we recommended that Daisy’s teeth be cleaned under anesthesia. The dental cleaning includes scaling and polishing just like your dentist does along with evaluation and treatment of any problem teeth. A dental cleaning done by a veterinarian under anesthesia is the only reliable way to remove tartar under the gum line. Because dogs and cats must be anesthetized to have the dental cleaning performed, a number other tests are required prior to anesthesia to ensure that the procedure is done as safely as possible.

By that morning in September, Daisy was up to date on all her vaccines, and the pre-anesthetic blood panel that was performed just a few days before revealed no abnormalities. The blood panel evaluates liver and kidney function, blood sugar, electrolytes, and red and white blood cell counts. Urine testing helps us evaluate the bladder as well as the kidneys.  A couple more steps were necessary, however, before Daisy was ready to undergo anesthesia. An EKG test and a chest x-ray were performed to evaluate the health of Daisy’s heart and lungs. Though everything sounded normal through the stethoscope on her previous check-ups, these more advanced tests are much more sensitive at picking up abnormalities than simply listening with a stethoscope. The EKG showed that Daisy’s heart had a normal rate and rhythm.

The final step, the chest x-ray, was when Daisy gave us all a surprise. A normal chest x-ray shows the heart surrounded by the lungs. You can see the size and shape of the heart, and you can make sure the lungs are clear.  Normal lungs filled with air look black on an x-ray.. Daisy’s chest cavity, however, was almost completely filled with white. There was a very small space near her spine that appeared to be normal lung tissue, and you could barely make out the outline of her heart, but the remainder of her chest was completely abnormal. Daisy had less than a third of normal lung capacity. Needless to say, her dentistry was not done that September day.  Instead, we needed to discover just what was filling Daisy’s chest and compressing her lungs.

The next step was an ultrasound or sonogram, of Daisy’s chest. This diagnosed a condition called a diaphragmatic hernia. The diaphragm is a large, flat muscle that separates the chest cavity from the abdomen. In Daisy’s case, there was a hole in that muscle, allowing her abdominal organs to move up into her chest. The two most common ways that this happens are a congenital defect or trauma. It was discovered that Daisy was adopted from a rescue group when she was about 3 years old. She came from Puerto Rico, and prior to that, her history was unknown. 

Extensive surgery was necessary to repair the hole in Daisy's diaphragm and to return all her organs to their normal positions. Parts of her liver, gall bladder, pancreas, and small intestine were all located in her chest cavity. Though we don’t know for sure, the appearance of the diaphragm at surgery was consistent with a traumatic injury, such as being hit by a car, rather than a congenital defect. So Daisy had been living with this condition since before she was rescued and adopted - for at least 5 years!

There were no outward signs, not even an abnormality on Daisy's physical exam. What  Daisy did have was a serious condition that significantly altered her anesthetic risk.  It would have been dangerous to anesthetize her without the knowledge we learned from the x-ray, since her breathing function most certainly would have been compromised.

Daisy’s condition, while rare, is just one example of the many possible conditions that pets can have that have no outward signs. This is what makes pre-anesthetic testing vital to the safety of our patients, particularly senior patients. Indeed, whether or not our patients need anesthesia for an upcoming procedure such as a dental cleaning, we strongly recommend a senior wellness panel every 6 months to allow us to diagnose medical conditions that, at least initially, don’t have any outward signs. This gives us a baseline when the pet is healthy, it allows us to perform anesthesia much more safely, and to begin to treat diseases before they make our patients sick. 

Daisy’s owners are sure glad we took that step!