Many animals find canned food more palatable because they like the taste and texture, Brooks says. You can top their favorite dry food with room-temperature wet food.

Dogs like a warm or room-temperature (not hot or cold) meal. Avoid serving him day-old wet food from the refrigerator, and keep his food away from heat. Another reason he might not be eating: It's too hot outside.

Dogs prefer consistency when it comes to their food. Don't change every day, but try a new flavor, such as lamb or chicken, and see if he responds (it may trigger his sense of smell). To avoid an upset stomach, introduce a new food by mixing it with his old food in equal increments each day.

Common mature-dog health issues, such as arthritis or joint pain, can make it difficult for him to access his bowls. Keep food and water where he spends most of his time. Put a water bowl on all floors of the house, too.

Older pets are at a higher risk of dehydration. Provide a clean bowl with fresh water at all times. It will help prevent disease, such as a kidney condition, and aid in digestion.

Dogs are people pleasers. If you see him eating, give him a little verbal reward. He'll know it makes you happy and will repeat the behavior.