Mystery of polar bear Knut’s death solved

Researchers discovered the famous polar bear had anti-NMDA receptor encephalitis. It is the first time the condition has ever been diagnosed in an animal.

BERLIN // Knut, the star polar bear who was hand-reared at Berlin zoo after his mother rejected him, had a type of autoimmune inflammation of the brain that is found in humans.

Knut, who was 4 years old when he drowned at the zoo in 2011, was reared by his keeper Thomas Doerflein.

Fans from around the world came to watch them play together, earning the zoo millions and inspiring a dizzying range of merchandise.

Knut had an epileptic fit and drowned in a pool in his enclosure. While a postmortem revealed he had encephalitis, or swollen brain, scientists had remained puzzled by the exact cause of the illness.

Now animal and disease experts have tested samples of Knut’s brain for a condition known as anti-NMDA receptor encephalitis, which affects about 200,000 people a year.

They said high concentrations of NMDAR antibodies in Knut’s cerebrospinal fluid resolve the puzzle of his death. “Knut died because of encephalitis, an inflammation of the brain,” said Alex Greenwood, head of the department for wildlife diseases at the Leibniz Institute for Zoo and Wildlife Research.

“The inflammation caused him to lose his motor control and he lost his balance and fell into the water and drowned.”

The results of their findings were published in the journal Scientific Reports. It is the first diagnosis of the condition in an animal.

By the time Knut had reached adolescence, he had generated €5 million (Dh20.5m) for Berlin zoo. Other German zoos have tried in vain to create celebrity animals to match his fame.

* Reuters