Some speculate that separating the polar bear and his keeper led to a decline in both their health:

The celebrity polar bear was pictured walking morosely around his enclosure and staring at the ground, a far cry from the happy images of him with ‘surrogate father’ Thomas Doeflein as a young bear.

Mr Doerflein, 44, was found dead amid fears that he became depressed after he was told to stay away from Knut because they were too close.

Doerflien had to give up playing with the bear due to Zoo administration fear for his safety. It would seem the separation was more dangerous.