Kenneth, the oldest of four bears at the zoo, has lived there since 2002.
Staff biologists noticed Monday that the 27-year-old bear was having trouble moving but he showed some improvement after treatment, zoo veterinarian Holly Reed said. A follow-up exam Tuesday revealed no broken bones, but Reed suspected possible neurological damage.
When Kenneth lost mobility in his right front leg, zoo staff decided Wednesday morning to euthanize the bear because he already had severe arthritis in his right rear leg and would be rendered paralyzed on one side.
“We focus on quality of life with these bears,” Reed said about why Kenneth was euthanized.
Kenneth weighed 870 pounds and was born in Canada, according to zoo records. He and Boris, another polar bear, were brought to Point Defiance a decade ago after U.S. Fish and Wildlife agents seized them from a Mexican traveling circus in Puerto Rico.
Zoo officials said Kenneth was approaching old age for a bear in captivity. Polar bears rarely live to be 20 years old in the wild.
The zoo’s other polar bears are Blizzard and Glacier.