The following is an excerpt from Petfinder.com’s The Adopted Dog Bible
Use ceramic, pyrex, or stainless steel bowls to feed your dog, and make sure they’re heavy enough that they won’t tip or spill while he’s eating. Don’t use plastic bowls, because plastic is a breeding ground for germs, and it can retain the smell of cleaning products and previous meals, which may discourage your dog from eating.
Do not use strong detergents or bleach to clean your dog’s food and water dishes, as these products can be toxic. Instead, wash bowls between feedings with a mild dishwashing detergent, and always rinse thoroughly.
Many older dogs suffer from arthritis or other health problems that can make eating difficult. Try elevating the dishes off the floor so your dog can reach the food more easily. You can find several different varieties of dishes at your local pet supply store or from an online retailer.