Guinness World Records officials did not immediately respond to inquiries about a successor to Stewie's record. The previous record-holder, Leo, a 48-inch-long Maine Coon owned by Frieda Ireland of Chicago, died several years ago.
Stewie was diagnosed in early 2012 with Lymphosarcoma, a malignant disease of the lymphoid tissues. He responded successfully to chemotherapy and was declared cancer-free, but the remission period was brief, and a vet recently found another, more aggressive tumor on his kidneys, Hendrickson said.
"I knew that although we could fight it, the end was near and so I wanted to simply make him comfortable and let him enjoy the time he did have," she said.
Associated Press writer Steven DuBois contributed to this report from Portland, Ore.