Neurological disease in wild tigers has recently been gaining prominence following a series of fatal canine distemper virus infections affecting tigers in Russia. However, new research into similar neurologic signs affecting a wild Bengal tiger in Bhutan diagnosed a brain lesion caused by a human tapeworm - the first time the condition has been recorded in a non-domestic cat species.

A research team, including the Cornell Wildlife Health Center’s Dr. Martin Gilbert, published a case report describing the death of a Bengal tiger in Bhutan from neurocysticercosis (the presence of larval tapeworm stages in the brain). Neurocysticercosis has also been reported in domestic dogs and occasionally in cats but has never been reported in an exotic felid. Bengal tigers are endangered, with only 103 individuals estimated to remain in Bhutan, with more in other range countries including India and Nepal.

Taenia solium, colloquially known as the pork tapeworm, causes a zoonotic disease that cycles between pigs – who ingest parasite eggs in contaminated food or soil – and humans, who ingest another stage of the parasite by eating undercooked infected pork. It is one of the major neglected tropical diseases in Southeast Asia. Larval stages migrate throughout the body and cause various symptoms depending on location.

It is unknown how the tiger became infected. The tiger may have ingested food or water contaminated with feces from an infected person. The transmission of zoonotic pathogens is likely to occur more frequently as the human-domestic animal-wildlife interface continues to expand. This finding highlights the importance of enhancing our understanding of the impacts of infectious diseases and parasites on endangered tiger populations in landscapes that are increasingly dominated by people.

Written by Isabel A. Jimenez, DVM ‘19