Dogs normally live for an average of 10 to 13 years, and cats from 12 to 18 – while a pet tortoise can live anywhere from 50 to 150. We asked our readers how old their pets are to try to track down the most senior in the county… One of the oldest was 20-year-old Jet, a dog who Becky Yardley and her husband Obz rescued when she was five. She’d been abused by two previous owners. The first would beat her with a stick and left her with a deformed tail, and the second left her “riddled with fleas”. Becky, from Aylesford, said: “My husband said to the owners he would take her due to the lack of car…