I highly doubt this is true. I've never lived in a place outside of the developed world, but I also have never lived or visited a place where the sidewalks drowned in dog/cat poop and pee. In fact, I've never actually watched a cat pee on the sidewalk in places where it cannot be covered up, simply because that's not how cats tend to act.
Where are you getting your information from?
How much have you traveled?
What is your definition of city?
Do you have some proof?
Where are you getting your information from? How much have you traveled? What is your definition of city? Do you have some proof?