If your adult dog or cat is healthy, you may have chosen a pet food based simply on whether or not your pet will eat it. Cost may also play a factor in your decision. However, not all pet foods are equal, and feeding the right amount is not as simple as following the directions on the package (they're just guidelines). Choosing an appropriate diet can set your pet on a path of lifelong good nutrition and help prevent many problems, including allergies, nutritional deficiencies, skin and coat disorders, and obesity.