die of natural causes

世界最高齢の犬、プースケが亡くなりました。老衰はdie of natural causesと言うんですね。（GP）
'World's oldest dog' dies at age 26

Pusuke as seen around two years ago. (Photo courtesy of owner Yumiko Shinohara)
The world's oldest dog as recognized by Guinness World Records died on Dec. 5 of natural causes at the age of 26 years and nine months.

Pusuke, a male mutt, was over 120 in human years. He was kept by 42-year-old Yumiko Shinohara in Sakura, Tochigi Prefecture. Born while Shinohara was still in high school, in his puppy years Pusuke slept with his owner every day. He survived three run-ins with vehicles and was loved by neighbors.

On the afternoon of Dec. 5, Pusuke waited for Shinohara to return from an outing before he passed away while having his head rubbed.

"Thank you for the memories," Shinohara said.

(Mainichi Japan) December 7, 2011