A pacemaker can extend a dog’s life. (Courtesy photo)
Pacemakers were first used in dogs in 1968, eight years after they were first used in humans. Today, it is estimated that between 300 and 400 dogs receive pacemakers yearly. They have also been used in cats and horses.
Although there are no pacemakers made specifically for use in animals, veterinarians are able to obtain pacemakers that have been donated by human patients who have died and also from pacemaker manufacturers after the unit’s expiration date has passed, when they can no longer be used on human patients. Because dogs live much shorter lives than we do, and dogs requiring pacemakers are usually elderly, pacemakers from these two sources still have enough “battery life” to last the amount of time necessary.
Pacemakers are used in dogs to correct the same abnormalities that they are used for in humans. Normally, the body sends electrical charges to stimulate the heart’s four chambers to beat at rates that effectively pump blood throughout the body. Sick sinus syndrome and heart block are two conditions in which normal electrical activity in the heart is altered, resulting in a very slow heart rate and the need for a pacemaker. Breeds that are more commonly diagnosed with these abnormalities include cocker spaniels, pugs, and Doberman pinschers.
Because of a very slow heart rate, owners report that their dogs are experiencing weakness, coughing, difficulty breathing and/or fainting spells. Your veterinarian will make the diagnosis by listening to the heart with a stethoscope, feeling for a slow pulse rate, and doing an EKG.
In the summer of 1990, Skipper, a 12-year-old German shepherd owned by a man camping at Bolton Springs Campground came to our hospital. His owner reported that Skipper “wasn’t himself.” He was very listless, didn’t want to go on walks, and had actually fainted on 2 occasions. After detecting a very slow heart rate of 20 beats per minute (normal heart rate is 70-160 beats per minute), the EKG confirmed a diagnosis of heart block. Due to financial constraints on Skipper’s owner and the prospect of performing this type of surgery, we offered to implant a pacemaker at our hospital. While we were making arrangements to get a pacemaker and a technician to help program it, Skipper was treated with oral medication to help increase his heart rate. A representative from Biomed Technologies in North Andover supplied the pacemaker and programmed it to stimulate the heart to beat 90 times per minute, which was compatible with a normal dog’s activity level. A wire lead was attached to the heart muscle by opening up the abdominal cavity and the diaphragm. The wire lead was then attached to the pacemaker (about the size of a silver dollar), which was implanted underneath the skin on Skipper’s chest.
Skipper lived another 2 years and died from a disease totally unrelated to his heart (liver cancer).
East Bare Hill Road resident Fred Karotkin in a veterinarian.
