An overweight 6-year-old tabby cat named Elmer is at risk for conditions such as arthritis and liver disease, and his family worries about his condition. They are working with their veterinarian to help him shape up, but Elmer has other plans. Veterinarian Gary Thompson recommends increasing exercise for obese pets while decreasing calorie intake but admits that it can be difficult. "There is a difference between simple and easy," Dr. Thompson says. "Losing weight is simple -- consume fewer calories than you burn. However, as we all know, that is far from easy."