Did you know that the world's oldest dog is Bella. She is 29 years old. But, because 1 dog year equals 7 dog years, she is actually 203 years old. But, unfourtunately, she's dead now. She died in 2003. Here's the story. Bella's owners hadn't been in the house for more than an hour, (after leaving from Mablethrope ) when Bella started panting and yelping and collasped in front of the sofa. After taking her to the vet, they decided that she had to be put down-her deasease was just to strong. Sadly she didn't make it into the book of world records because she never lived a full life.