Canine distemper outbreak and laryngeal paralysis in captive tigers (Panthera tigris)

Abstract The canine distemper virus (CDV) could infect various wildlife species worldwide. The viral infection in large felids directly impacts wildlife conservation. This study aimed to understand better the burden of CDV outbreaks in captive tiger populations in Thailand and a novel discovery of their clinical signs with a history of CDV exposure. We followed up on their infection from June 2016 to October 2020 with laboratory testing and veterinary medical records. The cumulative morbidity and mortality rates were relatively high. Moreover, 50% of the tigers survived at 2 years after infection. Approximately 38% of CDV infections were detected with laryngeal inflammation, which developed into paralysis in almost 50% of cases. Altogether, 50% of tigers with chronic infection developed stridor at 314 days after virus infection [95% CI: 302–320]. Our data indicates that laryngeal paralysis resulted from the CDV infection, potentially affecting the peripheral and central nervous systems. This condition can pose a life-threatening risk to tigers. The virus can spread quickly by contact with bodily excretion among tigers and fomite contamination once it affects a specific population. Implementation of biosecurity measures and vaccination is essential to mitigate the risk of disease spread and infection rates in tiger populations.