Pet droppings contaminate the environment with bacteria, parasites and stench. The droppings are one of the leading sources of "E. coli" (fecal coliforms) bacterial pollution: one gram of dog feces contains over 20,000,000 "E. coli" cells. Coliform bacteria and "E. coli" are commonly-used field indicators of fecal contamination by animals (including human). Pet droppings contain eggs of Toxocara canis and Neospora caninum parasitic worms. In adult dogs infection with T.canis usually asymptomatic but can be fatal in puppies.T. canis can cause parasitic worm infection and rarely blindness in humans. N.caninum causes severe losses in livestock breeding. While an individual animal's deposit of feces will not measurably affect the environment, the cumulative effect of thousands of dogs and cats in a metropolitan area creates serious problems due to contamination of soil and water supplies. The runoff from neglected pet waste contaminates water, creates health hazards for people, fish, ducks, etc.