Lets not stick to dogs, lets expand it to cats as has been previously stated, then lets look at horses, they may not be as numerous, but they leave a lump that you can trip over.
Then we should expand it to birds, lets start with pidgeons they make a mess on cars and public buildings, then lets expand it to seagulls, they fly in flocks from the tip just letting rip at will........I think I may have overstated it a bit, but it is just as daft as the original idea
