One of the animals carted into the clinic that day would later be identified as Pepper, the adult, female Dalmatian who had recently disappeared from the Lakavage family's 82-acre farm near Slatington, Pa. While her former owners searched for her in vain, it's likely that Pepper was being stowed in a kennel on the roof of the hospital. It's also likely that her vocal cords were severed when she arrived, leaving her unable to bark and howl in her final hours.
Pepper spent just one night in the Montefiore kennels. Sometime on July 2, she was brought down to the dog lab, anesthetized, and prepped for surgery. A hospital spokesman later told the newspapers that she'd been scheduled to receive an experimental pacemaker.
By the summer of 1965, Seymour Furman had already worked out the basics of transvenous pacing. His technique enjoyed a significant following overseas, and the American medical device company Medtronic had just introduced its first commercial pacemaker with catheter leads. But there were plenty of problems still to be solved. Batteries died, pulse generators would fail, and patients had to make frequent return visits for follow-up surgeries. That year, the Atomic Energy Commission would start work on a durable, nuclear-powered pacemaker. (The first of these was implanted in a dog in 1969.) When Pepper arrived at Montefiore, Furman was hard at work developing his own, more permanent device, and he needed animals for testing.
On that Friday, Pepper's chest would have been opened like the other dogs, her sternum separated, and her venae cavae tied off to empty her heart of blood. It's not clear when or how the procedure went wrong. Perhaps the surgeons couldn't finish the operation in time to restore her circulation. Or maybe the induced heart block was too severe. Whatever happened, the experiment was a failure: Pepper died on the table.
The loss of a single Dalmatian meant little to the pacemaker program at Montefiore. The new prototypes would be tested on another dog, and another, and many more; Furman's research yielded plenty of discoveries in the years that followed. (To name just one: In 1967, he devised a way to check the function of an implanted device automatically over the telephone.)
Not even the doctors who were performing these experiments understood just how important the new inventions would soon become. Heart disease was already America's leading cause of death in 1965, as it had been since about 1930. But few cardiologists at the time had ever seen a case of heart block—most of its victims were elderly people with modest access to medical care, and they were dying before anyone could make a diagnosis.
That all began to change with the invention of Medicare. On July 9, less than a week after Pepper's death, the Senate voted to make health insurance universal for elderly Americans. Nineteen million patients enrolled in the program the following year, and it soon became obvious how many adults were suffering from slow heartbeats in their old age. Now, for the first time, there was enough money to treat them all.
The particulars of Pepper's death scarcely mattered to the revolution in cardiology. But her final moments on the operating table do carry their own historical resonance: Medical science as we know it today—constructed on a framework of experimentation, observation, and reason—had begun in much the same way a few centuries before, with a dog laid on its back, its breast cut open, and its heart snipped in two.
What might easily be called the founding experiments of modern medicine were conducted in the first decades of the 17th century, by English physician William Harvey. His crucial discovery that blood circulates in a closed system began with a series of gory demonstrations on the bodies of living animals. For one, he would expose the beating heart of a dog, horse, or other creature and puncture its left ventricle. The geyser of blood that erupted with each contraction suggested that the motion present in the arteries and veins wasn't mere sloshing about, as had been the theory, but rather the result of a "forceful systole" of the heart.
Those skeptical of Harvey's conclusions opened the bodies of living dogs to see for themselves, and according to historian and philosopher of science Rom Harré, the dog soon became a standard instrument for the study of circulation. By the mid-1660s, Christopher Wren had devised a method for the intravenous injection of chemicals—opium and Spanish wine, to start with—into the bloodstream of a dog, and Richard Lower had performed the first successful blood transfusion by using a chain of quills to connect the artery of one dog to the jugular vein of another.