Veterinarians at the Cornell University Hospital for Animals successfully implanted a pacemaker in Nix, a miniature donkey who was regularly collapsing due to a severe heart condition. This is the first surgery of its kind in a large animal species at Cornell.

Nix’s collapsing episodes and overall lethargy began in the fall of 2020 when she was only a few months old. In February of this year, Nix’s condition worsened.

She was referred to Cornell, where veterinarians did an echocardiogram and placed an ECG on her, to record the heart’s rhythm. With this information, Nix’s care team diagnosed her with third degree atrioventricular block. Without getting enough blood to her brain or around her body for long periods, Nix exhibited the classic clinical signs of this condition, including collapse, episodes of weakness and severe exercise intolerance.

Given Nix’s age and her lack of other underlying problems, she was a great candidate for a pacemaker. In a collaborative effort between Dr. Katharyn Mitchell, assistant professor in the Section of Large Animal Medicine, Dr. Barbara Delvescovo from the large animal internal medicine service, Dr. Lawrence Santistevan of the cardiology service, members of the large animal soft tissue surgery service, the anesthesia service and multiple hospital staff members, the complicated procedure to implant Nix’s pacemaker went well.

Nix’s care team noticed immediate improvement after surgery. At Nix’s recheck appointment this month, the pacemaker was working well, and if it continues to do so, Nix will live a normal life. She will be back for another recheck in a few weeks, but in the meantime, owners Mindy and Carlton Lockwood are celebrating Nix’s second birthday.

“Nix’s care at Cornell was exceptional,” said the Lockwoods, adding: “we really appreciate what they were able to do for her.”

The full version of this story appears on the Cornell University College of Veterinary Medicine website.