Experts say the two deaths points out the small, but real risk of anesthetizing even healthy animals. Don DeYoung, interim director of veterinary animal care at the University of Arizona, said the decision to anesthetize an animal is never taken lightly, especially with older animals. Zoo officials were stunned and saddened by Natasha's death, VanPeenen said. There are no immediate plans to replace Natasha or move Boris, she said. A necropsy done at the University of Arizona shortly after Natasha's death did not explain the death, VanPeenen said.
Further tests are under way.