Photo by the San Diego Zoo
The San Diego Zoo discovered that one of their four resident Tasmanian devils, Nick, was suffering from a heart conduction disorder. This caused his heart to beat slower than normal during a routine exam in January, which was confirmed by an echocardiogram (ECG) and an electrocardiogram (EKG). The difference in the two tests lies in the sensitivity. An ECG is a more advanced testing procedure that relies on ultrasound (high-frequency sound waves) to give a visualization of the internal heart structures, where as an EKG records the heart’s electrical activity. “His heartbeats were too slow and now the pacemaker is going to actually take over (pacing) his heart and is going to determine when to pace fast or slow depending on his activity,” said Dr. Joao Orvalho, a cardiologist at the University of California Davis Veterinary Medical Center in San Diego.
The zoo veterinarians decided to consult with Dr. Joao Orvalho, who suggested surgical intervention was necessary, and that installing a pacemaker to regulate Nick’s heartbeat would be the best option to improve his quality of life. “We have not done one of these before, ” Dr. Cora Singleton, San Diego Zoo’s associate veterinarian said. “This type of heart disease has been documented in Tasmanian devils as they get older, but most facilities don’t place a pacemaker, so we are the second in the United States to perform this procedure. ”
On May 11, 2016, Nick underwent an operation to install a pacemaker. Dr. Joao Orvalho, performed the pacemaker implantation procedure along with Dr. Fred Pike, a surgeon at the at the University of California Davis Veterinary Medical Center in San Diego.. Because this was a unique case, the leads of the pacemaker were sutured in the Tasmanian devils heart; however the pacemaker had to be placed in Nick’s abdomen instead of the neck, which is typical for most animals. “Typically when a pacemaker is placed, it’s placed within the neck area,” said Dr. Fred Pike, the surgeon during the procedure. “But because of the conformation area and the shape of the neck, that’s not possible.”
The operation was a success and there were no complications. Nick was released the same day and returned to San Diego Zoo’s hospital to recuperate from the surgery. “So far everything looks really good”, said Dr. Fred Pike. Zoo veterinarians in an off-exhibit area monitored Nick closely for two weeks after his surgery. Nick will receive additional check-ups and fine-tuning of the pacemaker in three to six months and then annually after that. “We are optimistic that this procedure will give Nick an additional one to two years of a happy and healthy life,” said Dr. Cora Singleton.
The San Diego Zoo is home to many animals. The zoo has four resident Tasmanian devils. These animals are native to Tasmania, an island off the coast of Australia. These nocturnal animals are about the size of a small dog and face extinction due to the formation of a rare, but highly contagious disease called Devil facial tumor disease (DFTD) that is only found in the Tasmanian devil. The disease spreads through normal biting behaviors during mating or feeding. There is no cure for the disease and it has been fatal in every animal that it has been found in. All four of the Tasmanian devils at the San Diego Zoo are disease free.