Bleeding edge medicine Part 2: Fixing little dogs with too much heart

Patty Khuly, DVM
Updated: October 05, 2010
Published: November 19, 2006
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Teeny-tiny dogs often have more heart than most people think. And that’s not just because the bigness of their personality is inversely proportional their size. Some of these teeny pocket-pooches can have a bit of extra vascular tissue near their heart that keeps them from surviving beyond one or two years of life.

It’s called a PDA (patent ductus arteriosus), where oxygen-poor blood (having dumped its load in tissues throughout the body) is shunted over to a vessel carrying oxygen-rich blood instead of making its way through the lungs to pick up this must-have molecule. The extra vessel that performs the perverse act of diversion (between the aorta and pulmonary artery) is one that serves a true function in the prenate but which, failing to recede pre-birth, results in an erroneous, chronically oxygen-depleted state by six to twelve months of age.

Sad, but relatively common (7 out of 1000), especially in the tiniest of breeds (Poms and Maltese), PDA patients trudge inexorably down the road of heart failure. As the stressed heart works harder and harder to feed the body more blood, it inevitably fails when the developing creature’s oxygen requirements become to great a load for it to bear.

The characteristic heart murmur that accompanies PDAs is typically audible even at birth. For some obscure reason the murmur is often missed during routine puppy checks (I don’t know how this happens, as it is a prominent murmur—but, disgracefully, it does). So pups usually present later in their puppyhood—around eight to ten months of age—with signs of lethargy, exercise intolerance or even end-stage heart failure.

Thankfully, there is a cure—a nearly 100%, no-fail cure when performed by a qualified vet surgeon, that is. And here’s where we get to the tricky cusp of vet technology where there are no substitutes for the highest quality care the patient`s family may not be able to afford. If you have space on your credit card for three thousand dollars of vet care then you’re in luck. Because there is no alternative treatment available, these pups will eventually die before they hit the 18-month mark—if that.

I currently have one of these diminutive patients under my care. Reynaldo is a three-pound, six-month-old Maltese with a sparkling personality and a dwindling quality of life just ahead of him. His owner has known of his condition since he first came to us as an eight-week-old, pet shop rescue (I have opinions about `rescuing` dogs via checkbook but I won’t go into them here), but has been unable to afford his surgery.

Because Reynaldo’s mom worked for our hospital for thirteen years, Miami Veterinary Specialists has graciously consented to a payment plan. As a retiree, however, she’s so cash-strapped she may not be able to afford the fix. IMHO, I believe that until Reynaldo becomes symptomatic for this disease, she will not face the reality and take the financial leap—by whatever means necessary.

Though fraught with the inherent risks of any open-chest surgery, the procedure is actually quite simple. The offending vessel is carefully sought out and exposed via delicate dissection around the base of the heart. It is then clipped closed with a special stapler-like device. That’s it.

The best part of the surgery, says Dr. Wosar of Miami Veterinary Specialists, is hearing all the monitors in the room beep in celebration. As the oxygen levels in the body rise, the pulse oximeter makes soothing, slowing beep-beep and the esophageal stethoscope reports slower, gentler swoosh-swoosh sounds. This dog is now 100% cured and can live a normal life with an undiminished lifespan.

There are few procedures that can accomplish such a feat and consequently, few are so satisfying for a veterinarian. As a generalist, you might expect that I don’t get to share in the glory. And while the client may not lavish me with praise, I always feel that glowing pride in knowing I had a hand somewhere in the process.

I’m confident that Reynaldo will soon experience the benefit of the procedure. I’ll keep you posted—and perhaps I’ll share some audio of his procedure with you so you can feel like you had a hand in it, too.