YOU SAID:
I wanna pet my brown dog named duke, though last year he died.
INTO JAPANESE
デュークという名の犬をペットにしたいのですが、去年死んでしまったのです。
BACK INTO ENGLISH
I want to pet a dog named Duke, but he died last year.
INTO JAPANESE
デュークという名前の犬をペットにしたいのですが、彼は去年亡くなりました。
BACK INTO ENGLISH
I want to pet a dog named Duke, but he died last year.
That didn't even make that much sense in English.