According to recent estimates, nearly 60% of all households own at least one pet in the United States. Cats and dogs are the most commonly owned pets. Pet ownership has been shown to have many positive health benefits, such as lowering blood pressure, reducing depression, and moderating stress. Children raised with pets had improved social development, including better nonverbal communication and social competence. While most pets are primarily kept for companionship, dogs may be trained to assist disabled people or aid in hunting, herding, tracking, or guarding.
However, there is a great risk associated with pet ownership. An estimated 4 million pet-derived infections occur in the United States annually.4 Domestic dogs have long been recognized as a source of zoonoses for people. In particular, zoonotic bacteria and parasites harbored in the canine intestine have been shown to pose a significant risk to human health.
People are exposed to these pathogens through direct or indirect contact with infected dogs or their feces, and they may become infected after the inadvertent ingestion of a zoonotic agent. Organisms identified include Toxocara canis (roundworms), Echniococcus granulosus (tapeworms), Giardia duodenalis, Cryptosporidium spp., and Campylobacter spp.3
Every year, bathing in coastal waters polluted with fecal contamination is estimated to cause more than 120 million gastrointestinal illness cases and 50 million cases of respiratory disease around the world. These cases are caused by various fecal pathogens introduced into the aquatic environment by various sources, including dog and cat waste.1
Recent studies show that dogs are the largest contributing animal source of fecal bacteria (enterococci) on beaches where dogs are allowed. Dog owners are generally not required to clean up their dog waste, even though a beach is a designated recreational swimming area.2
Bacteria in Feces
One study found that a single gram of dog feces contains 23 million fecal coliform bacteria. In addition, pet poop contains nitrogen and phosphorus, two elements that fertilize algae and other aquatic plants and make them grow out of control. And the more poop, the more bacteria, nitrogen, and phosphorus.
In a densely populated watershed in Arlington, Virginia (Four Mile Run), scientists estimate that dogs deposit more than 5,000 pounds of poop each day.5 A typical dog deposits three quarters of a pound of waste per day. 50,000 dogs would deposit about 37,500 pounds, or 19 tons of dog waste each day.6 The 78 million dogs living in the United States create 10 million tons of feces annually, polluting waterways and posing a threat to public health.
Hundreds of puppy mills with thousands of dogs are spreading dog feces on farm fields. This is being permitted by both local environmental protection agencies and USDA. This is a dangerous threat and one that is impacting water quality and is certainly a pathogen problem for water and soil contamination. These puppy mills should be required to put in dog waste treatment systems.7
Making a Difference
People don’t realize that the average pile of dog waste may contain 3 billion fecal coliform bacteria, plus other, sometimes dangerous, microorganisms. Most people don’t stop and think about how their pet contributes to the cumulative impact, and they have never seen the link between dog waste, public health, and water quality.8 Some even think that dog poop is good for the grass!
Rather than leaving dog waste on the ground, pick up after your dog. Otherwise, it will end up in the storm drains and our waterways. It’s one way to be a Responsible Pet Owner and help to keep our planet green!
Of course, dogs are not the only animal causing potentially serious waste polution. Cats are equally responsible.
Image Credits: TBIT
- Halliday et al. – Bacteria In Beach Sands: An Emerging Challenge In Protecting Coastal Water Quality And Bather Health
- Wright et al. – Microbial Load From Animal Feces At A Recreational Beach
- Himsworth et al. – Multiple Zoonotic Pathogens Identified In Canine Feces Collected From A Remote Canadian Indigenous Community
- Stephen J. Ettinger & Edward C. Feldman – Textbook of Veterinary Internal Medicine
- EPA – Stop Pointless Personal Pollution!
- EPA – News-Notes, June 2002, Issue 68
- EPA – Chesapeake Bay Total Maximum Daily Load (TMDL)
- EPA – News-Notes, December 2007, Issue 83