Toby, a 22-year-old Kodiak bear with degenerative joint disease, was euthanized Sunday at the Buffalo Zoo.
Toby was being treated with anti-inflammatory medications for progressive osteoarthritis that led zookeepers to move him to a more comfortable off-exhibit area to relieve his joints.
"While the majority of our bears are certainly showing signs of age-related issues, the Buffalo Zoo remains committed to providing high-quality care for them for the duration of their lives," said Donna Fernandes, president and chief executive officer of the zoo.
"All of our bears are beloved by our staff and visitors. Toby, especially, will always have a special place in our hearts and will be greatly missed."
Kodiaks are the largest subspecies of brown bear and are found on islands of the Kodiak Archipelago in Alaska.
A zoo spokeswoman said Toby's records show he was transferred after three years at the Olympic Game Farm in Washington State to the Grizzly and Wolf Discovery Center in Montana, where he was housed with Fred, a grizzly bear. Toby and Fred both came to the Buffalo Zoo in 2002, residing in the same exhibit until Fred was euthanized in 2010 after age-related neurological changes stemming from paralysis.
The zoo has six other bears, with five at or approaching the end of their life span, considered to be 20 to 25 years. The other bear is Anana, an 11-year-old female and one of two polar bears for which the zoo is planning a new facility that is currently in design.
There are also four Andean (spectacled) bears and three grizzlies.