Bowls come in a variety of materials. Many are dishwasher safe, but more elaborate bowls need to be hand washed. When it comes to dog bowls, SIZE really does matter. The bigger the dog, the bigger the dog bowl, be careful with your choice. Your dog food bowl should be large enough for a meal; usually water bowls are larger so you don't have to refill as much. Elevated dog bowls and dog feeders are easier for large breeds and senior dogs and aid digestion.