The Cape May County Zoo's Siberian tiger has been euthanized.

County officials said Rocky, the 16-year-old tiger known as a favorite to zoo visitors, died Friday.

The aging tiger had been having problems with his hips and hind legs, and was having difficulty walking, authorities said.

Rocky had lost muscle mass and suffered from a degenerative spine condition, osteoarthritis in his hips, and complications from previous surgeries in his right hind leg, where cancerous tumors were removed .

The problems "were greatly impacting his quality of life and the difficult decision was made to euthanize him," the county wrote on its Facebook page.

Rocky had been at the Cape May zoo since 2002.

Siberian tigers, also known as Amur tigers, typically live 16 to 20 years in captivity and up to 10 years in the wild.