Obesity is a common nutritional problem in dogs and cats. Being overweight can lead to a lot of problems, including arthritis, heart disease, diabetes and certain types of cancer. It has even been shown to decrease life expectancy in dogs. When talking obesity, it helps to feed your pet regular meals every day rather than having food available to him all the time; decrease or eliminate treats; and prevent additional foods. Increasing exercise helps, too, assuming your pet is healthy enough to do this. Your veterinarian can tell you if your pet is obese and help you determine how much weight he needs to lose, as well as help you create a plan to address his weight-loss goals.