I grew up in a United States Air Force (USAF) family and have lived in all parts of the world from Japan to California. I enlisted in the USAF right out of High School. It also took me to places around the world like Germany and Guam.
Besides glass, stainless steel is the cleanest way to go! Keep paint in mind with glass, but stainless steel helps to alleviate germs. Wash out dog bowls daily. This is a bulky item.