Aussie, the oldest male polar bear in North America, was euthanized Friday at Brookfield Zoo.

At 32 years old, Aussie was experiencing several age-related degenerative diseases, according to a statement from the zoo announcing his passing. He had been on a variety of pain relievers, including several drugs used for treatment of arthritis in elderly people and dogs, which kept him comfortable.

Over the past several weeks, veterinary and animal care staff noticed a gradual decline in his condition and decreased response to medications.

“Our primary focus is always the wellness of our animals,” said Dr. Michael Adkesson, vice president of clinical medicine for the Chicago Zoological Society, said in the statement.

“Aussie has been part of our family here at Brookfield Zoo for more than 30 years, and today is a difficult day for our team. However, it is the best decision for Aussie as medications could no longer control the pain associated with his age-related arthritis. Our staff could tell his comfort was really declining and knew it was the right time. It is very similar to the tough decisions that people must make for their pets at home in deciding when to say goodbye,” Adkesson said.

Aussie was born at Adelaide Zoo in Australia in June 1985 and arrived at Brookfield Zoo a year and a half later, according to the statement. He was introduced to one of the zoo’s female polar bears and together they produced five offspring, including Hudson, who is now 11 years old. Aussie also had four “great grandkids.”

Hudson and a 24-year-old female polar bear Nan remain at the zoo.