When choosing a dog food, you should consider the dog's level of activity, tendency to gain weight, oral health needs, stomach sensitivity, skin sensitivity, need for nutritional balance, and presence of harmful preservatives. The best food choices are those that meet the dog's energy needs based on activity level, help control weight, improve dental health, are easy to digest, soothe itchy skin, provide a balanced ratio of meat, vegetables and grains, and avoid chemical preservatives. Homemade food tailored to the individual dog's needs is the healthiest option when possible.