I know it's easy to think dogs don't need to have their food bowls cleaned when they do gross things like drink from the toilet, or eat dead animals without hesitation. I was guilty of cleaning my boys' bowls maybe once every couple weeks. I never considered doing it more often since the bowls never *technically* looked dirty, so I thought what was the harm? Until one day, I happened to touch the bottom of a water bowl that was empty and found that it was covered in a slick, clear film. I genuinely thought it looked clean! Yuck! So, here's why you need to wash those bowls.
The film at the bottom of the bowl
That film is actually a layer of bacteria that comes from many different things; like your dog's saliva, whatever particles are floating around in your home, or whatever is in your dog's mouth at the time they take a drink or eat from the bowl. Your dog's bowl is almost like a petri dish (gross), and sometimes what grows inside can be harmful and cause health problems, like digestive issues. It's been studied that even bacteria like, Staph and Salmonella, can be found in your pet's bowls! If you have children in your home, that can be very harmful if they love to get into the dog's things.
What to do
It's very easy to avoid dirty bowls, just be mindful and wash your dog's bowls at least twice per week with hot water and regular dish soap. Easy as that!
You can also put them into the dishwasher if that makes your life even easier, but I would scrub them down first to get that film removed. I've also heard you should use stainless steel or glass bowls only. Plastic is porous on a microscopic level and that bacteria can sit there even after being thoroughly washed. If bowls are worn down, peeling, or chipped, make sure you replace them so chemicals don't leak out of the materials into your dog's food or water.