Laws that require dog owners to clean up after their pets---so-called "pooper scooper laws"---have been enacted in a few jurisdictions to help curb the messes dogs might leave behind. Not only do pooper scooper laws help keep an area cleaner, they may also help prevent the spread of fecal diseases. And dog owners should note: Even if your jurisdiction will not fine you, you still may face a legal penalty for leaving dog poop behind.
In addition to being a nuisance to step in, dog feces can also be a carrier of diseases and parasites, such as tapeworm, salmonella, and E. coli. While these are not necessarily an immediate danger to humans, other animals may have close contact with the poop and contract the disease themselves, which may then spread. Even disease-free poop can be a hazard, as rainwater will frequently wash it into storm drains that discharge into waterways without treatment, greatly lowering the quality of the water.
To curb these problems, many jurisdictions impose fines on pet owners who do not clean up after their dogs. New York City enacted the first of such laws, called the Canine Waste Law, in 1978, and currently imposes fines of up to $250 for each violation. Other places, such as privately owned parks or clubs, may have their own procedure for levying fines on members who ignore their dog's feces.
In some cases, allowing your dog to poop on someone else's property may even subject you to a civil lawsuit, even if no formal pooper scooper laws have been enacted. If, as a result of your dog's feces, harm is done to private property, you may be required to pay for the damages. For instance, an individual that relies on groundwater for an outdoor well may lose the use of his well if your dog's poop sufficiently pollutes the water. You would then be liable for the damages.
Your Own Backyard
Though no laws prohibit you from allowing your dog to poop in your own backyard, neighbors may be able to sue you for a private nuisance if you allow the poop to accumulate. The courts have recognized that citizens have a right to live in a reasonably odor-free environment, and leaving your dog's feces in the yard for a long time may cause smells that interfere with neighbors' quality of life. While such situations are rare, extreme cases may subject you to personal liability.
Even in the absence of any law or civil suit, you might still be prevented from walking away from your dog's poop if you signed a contract promising not to. Some rental or home-owners association agreements specify that pet owners must clean up after their dogs. Generally, these contracts specify that the complex is permitted to charge you a certain fine for each infraction, and may even be able to terminate your lease if the problem is pervasive.