I have not been in a park that charges yet. However I am sure thing like that are coming to your local RV Park. Yes its another way (sad to say) to get much needed revenue. It falls in line with paying extra to guarantee the exact site you want even though you have reserved it. With all being said it most likely will boil down to pet owners not picking up after their pets. I will always find dog poop when walking my dog. The worst part is RV parks provide dog fenced in areas, with bags available and one will still find poop.