Here's some perspective comparing cat age to human age. "The World Health Organization says that middle-aged folks are 45 to 59 years of age and the elderly, 60 to 74. They consider aged as being over 75," says Debbie Davenport, DVM, an internist with Hill's Pet Foods. "If you look at cats of seven years of age as being senior, a parallel in human years would be about 51 years," she says. A geriatric cat at 10 to 12 years of age would be equivalent to a 70-year-old human.

Veterinarians used to concentrate their efforts on caring for young animals. When pets began to develop age-related problems, the tendency among American owners was just to get another pet. That has changed, and today people cherish their aged furry companions and want to help them live as long as possible.

Modern cats age seven and older can still live full, happy and healthy lives. "Age is not a disease; age is just age," says Sheila McCullough, DVM, another internist at University of Illinois. "There are a lot of things that come with age that can be managed successfully, or the progression delayed. Cats with renal failure are classic examples." It's not unusual for cats suffering kidney failure to be diagnosed in their late teens or even early 20s. "I had a client with a 23-year-old cat who asked whether she should change the animal's diet," relates McCullough. "I said, 'Don't mess with success!'" These days veterinarians often see still-healthy and vital cats of a great age. "I think if the cat lives to 25 years, I shouldn't be doing anything but saying hello," says Steven L. Marks, BVSc, an internist and surgeon at Louisiana State University. "If you've ever had a pet live that long, you want them all to live that long."