Medical mystery: How a dog's bad breath saved his life

Oliver Cosentino is a 2-year-old Labradoodle whose family adored him, but not his bad breath.

Indeed, he needed a dental cleaning, but because that requires anesthesia, the first step was some blood tests. The results showed an elevation in his SDMA value, an early detector of kidney disease. We hoped that it was simply an early sign of a urinary tract infection and not something more alarming, such as a congenital kidney abnormality or early kidney failure.

But another test showed the SDMA remained elevated, and now his protein was low.

All this time, Oliver was eating and acting perfectly normal. And yet, I had this nagging suspicion that something was really wrong, and it needed to be figured out before we cleaned his teeth.

Just before looking at his kidneys with an abdominal ultrasound, I started thinking about underlying, silent diseases that might stress otherwise normal kidneys in such a young dog. Addison's disease — yes, the same condition that affected President John F. Kennedy — came to mind.

Oliver's family was familiar with the disease, as a friend's dog had it. But unlike that case, Oliver acted normal, and his blood did not show an electrolyte abnormality, a hallmark of the disease.

So what was going on with Oliver?

In Addison's disease, the patient's own immune system attacks the adrenal gland, leaving it unable to make critical hormones. Typically, patients have had a history of repeated bouts of vomiting, diarrhea, needing to drink a lot of water, and often present as a medical emergency when undiagnosed for too long.

Further testing of Oliver revealed that his cortisol, a stress hormone, was very low. That led to one more test, an ACTH stimulation test. It proved that his gland was not up to the challenge of making more stress hormone when needed.

Voilà! Oliver did have Addison's disease, also known as primary hypoadrenocorticism. But his was a form that we call Atypical Addison's, making it more challenging to catch.

A properly functioning adrenal gland has two layers. One makes cortisol, the hormone Oliver didn't have, which normally is released as a "fight-or-flight" response. The other layer makes aldosterone, and without it patients can have life-threatening imbalances in electrolytes, such as sodium and potassium. Their blood pressure may plummet. Most dogs with Addison's have this form.

Purebred standard poodles, Wheaten terriers, and Portuguese water dogs have a genetic predisposition to the disease. Labrador retrievers, and Leonbergers also have an increased risk, but you may see it in any dog, though very rarely in cats.

We gave Oliver the appropriate steroid supplementation, and his kidney values reverted to normal. But the blood work showed a telltale electrolyte imbalance, so he also needs a monthly injection of a drug called Percorten, for the rest of his life.

With his Addison's under control, Oliver — to the relief of those who love him — got that long-awaited dental cleaning.

Dawn Filos is a veterinarian and owner of Bucks Mercer Mobile Vet, a house-call mobile practice in Bucks County and Mercer County. She blogs at www.askthepetvet.com, and can be contacted at Info@askthepetvet.com.