B.P.
I also have old, set in their way cats and a toddler who gets into everything. I have put the catfood and water on a tray on top of the dryer (I actually had to do that to keep the dog from eating their food). The litter box has a lid that she can't open and the opening faces the back wall where she can't get to it. I, unfortunately, don't have any better ideas for the dog's food and water so she does get into them quite frequently. I buy several canisters of antibacterial wetwipes at a time and always have them handy.