Most veterinary patients in need of a pacemaker are experiencing fainting episodes and/or are notably exercise intolerant.  The cause of the fainting and weakness is a slow underlying heart rhythm which usually is third degree (complete) atrioventricular (AV) block. Sometimes a high grade second degree AV block will create similar signs and can also cause a symptomatic dog. This translates into a heart with a normal beat originating in the upper half of the heart that is not getting conducted to the lower half.  The blocked conduction creates a heart that does not pump adequate blood to the body and brain.  Not enough blood flow is the reason dogs are unable to perform their normal daily activities.

To determine if your dog is a candidate for a pacemaker, we will need a complete baseline profile including a current blood profile, chest and abdominal X-rays, complete ECG evaluation, and an echocardiogram.  With the echocardiogram, we try to rule-out an organic cause of the block (such as a tumor) and check the function of the dog's heart.   If a lesion is found via the echocardiogram or significant heart muscle or valvular disease is present, your dog may be less suited for pacemaker implantation.

When your dog is scheduled for pacemaker implantation, we order the appropriate equipment from a central veterinary pacemaker supply.  Sometimes, this creates a delay as there is a national shortage of units.  However, we almost always have a complete set-up on hand for the patient in need of emergency pacing.

The animal is scheduled to arrive the morning of or evening before the surgery and a complete physical is performed - paying particular attention to any source of potential infection including a skin infection.  We are implanting a permanent foreign body and require as clean an area as possible.  After the procedure is performed, the animal is hospitalized an average of 48 hours to allow initial healing at the site of the implants and to monitor for effective pacing.

The procedure itself requires general anesthesia and fluoroscopic (real-time video X-ray) guidance of the pacemaker lead into the right side of the dog's heart.  The generator is permanently implanted in the underside of the neck.  Therefore, a harness must be used instead of a neck collar for future leash walks.