Dik, a Belgian Malinois, had a pacemaker implanted in spring 2002 at the Texas A & M Veterinary School. Here's some information from that Customs website:

"Between 10 and 20 dogs are diagnosed with heart conditions every day in the United States and Canada. "Between 100 and 200 pacemakers are implanted into animals-mostly dogs but some cats and horses-in the United States each year," notes Dr. David Sisson, a veterinary cardiologist at the University of Illinois College of Veterinary Medicine Teaching Hospital in Urbana.

Although Dik's pacemaker was a new one, an increasing number of people are donating their pacemakers along with their organs after death. Federal regulations prevent pacemakers from being passed from person to person for use, but the implantation of these "second-hand pacemakers" in animals whose cardiovascular arrangement is similar to the human system can keep the animals alive for years.

People who choose to be cremated must (by law) have their pacemakers removed first. Anyone in need of a pacemaker for a dog can contact the local funeral home, their veterinarian, or the American College of Veterinary Medicine in Lakewood, Colorado. at 1-800-245-9081."