West Nile Virus is a disease spread by mosquitos. Symptoms range from asymptomatic (no symptoms), to mild flu-like illness, to potentially life-threatening neurologic signs (affecting the brain and nervous system).  Primarily, West Nile virus can infect humans, birds, horses, and some other mammals. The Louisville Zoo had a rare case of West Nile Virus in our Komodo dragon. Romulus was 4 years old at the time, only 19 pounds, and still considered a juvenile.

He presented in the fall of 2021 with an abnormal posture (neck and head were curved to the right, abnormal gait (dragged his left front leg and his right front leg was weak), and he did not respond when staff entered the exhibit. Otherwise, Romulus seemed to behave normally, tongue-flicking and hissing. Vet staff decided it necessary to anesthetize Romulus for a thorough exam. X-rays showed that there were no broken bones in the limbs or spine. In fact, there were no obvious findings to explain the dragon’s abnormal posture. Blood and other samples were taken for testing to help narrow down the cause. Romulus was also given several different medications for supportive care. Due to the neurological signs, one of the top suspicions was West Nile Virus as the time of year was peak mosquito season and there were no obvious signs of injury.

Several exams later, including an MRI and cerebral spinal fluid tap, Romulus was diagnosed with West Nile Virus. With supportive care and time, he gradually improved and was considered back to normal within a few months after first presentation. He continues to grow and is close to 40 pounds at 7 years old.