Sheba, who arrived at the Singapore Zoo in 1978 from Cologne Zoo in Germany when she was just 14 months old, lived a long and rich life before she was euthanized a few hours ago. The polar bear had been under treatment since September this year for loss of strength in her hind limbs, but her condition deteriorated in the past week.
Wild Reserves Singapore, the parent company of Singapore Zoo, said that they are extremely saddened by the death of their beloved polar bear. But because a close evaluation showed that her prognosis was poor, she had to be euthanized on humanitarian grounds. Sheba was a key attraction at the Singapore Zoo for over 30 years and she lived to a ripe old age of 35 years, far exceeding the normal life span of 25 years for polar bears that are not in the wild.
Sheba was also the first polar bear to have successfully raise a cub in the tropics. Her son, Inuka, continues to be in the Singapore Zoo and is now 21 years old.
(Source)