Thanks for that great advice Mike!
I do wash the pets' bowls every time I feed them, hubby doesn't see the need, so he doesn't , but with both of us feeding them, they get washed at least once a day! And I always clean the bowl when refilling it with water, I've seen the scum if I don't!
I've often asked hubby, "would you like it if I served your dinner on the same dirty plate you had breakfast and lunch?" Just saying...