Litter Picking Dog

Throughout human history, people have disposed of unwanted materials onto streets, countrysides and remote places, unpunished. Prior to reforms within cities in the mid to late 1800s, sanitation was not a priority on governments' lists of things to do. Waste was disposed of by the roadside or in small local dumps. It was unsanitary for local inhabitants and the growing piles of waste led to the spread of disease. The only known pre-modern exception, however, was the Arab Empire, especially in Cordoba, al-Andalus, which had facilities for litter collection.
In the 14th century, the rise of waste in Europe helped contribute to the bubonic plague. Black rats, carrying the fleas which were the vectors for the plague, fed off the food scraps. Many plagues were started from litter.