Pet Feces Removal: The Hidden Health Risks in Your Backyard

Here’s something nobody talks about at the dog park: that pile your golden retriever just left behind is actually a biohazard.

We don’t say that to be dramatic, the science is just unambiguous. Dog feces is one of the most pathogen-dense substances commonly found in residential environments, and the Pacific Northwest’s cool, wet climate creates near-perfect conditions for those pathogens to survive and spread.

If you’re a pet owner in Western Washington, whether you’re in Tacoma, Poulsbo, Gig Harbor, or anywhere in between, understanding what’s actually in your dog’s waste matters for protecting your family, your community, and your local waterways.

Let’s get into the science. Fair warning: this gets a little uncomfortable, but that’s kind of the point.

What’s actually in dog waste?

A healthy-looking dog with no visible symptoms can still produce waste teeming with harmful organisms. According to research published in the Journal of Applied Microbiology and data from the Centers for Disease Control and Prevention (CDC), dog feces commonly contains the following:

E. coli (Escherichia coli)

Most strains of E. coli are harmless, but several pathogenic strains, including E. coli O157:H7, cause severe gastrointestinal illness. Symptoms include bloody diarrhea, abdominal cramps, and in severe cases, hemolytic uremic syndrome (HUS), which can lead to kidney failure.

E. coli spreads from dog waste through contact with contaminated soil, water, or surfaces. Children playing in yards where waste has accumulated are at particular risk. E. coli can also be tracked indoors on shoes and pet paws.

In PNW conditions, E. coli can persist in moist soil for weeks to months. A 2014 study published in Water Research found that E. coli survival was significantly extended in cool, shaded, moist environments. That describes most Western Washington backyards from October through May.

Giardia (Giardia duodenalis)

Giardia is a microscopic parasite that causes giardiasis, an intestinal infection characterized by diarrhea, gas, greasy stools, stomach cramps, and dehydration. The CDC estimates that Giardia infects approximately 1 million people in the United States annually, making it one of the most common waterborne diseases in the country.

Giardia cysts are shed in enormous quantities in the feces of infected dogs. These cysts are immediately infectious once passed and are resistant to many common disinfectants. They contaminate soil, groundwater, and surface water with alarming efficiency.

This is where it gets concerning for the PNW specifically. Giardia cysts can survive in cool, moist soil for several months. Water temperatures in the 35-50°F range, typical of PNW groundwater and streams throughout much of the year, are ideal for cyst preservation. A study in Parasitology Research demonstrated that Giardia cysts remained viable for over 11 weeks in water at 4°C (39°F).

For residents near Chambers Creek in Lakewood, the Kitsap shoreline, or any of the tributaries flowing into Puget Sound, this has real implications for local water quality.

Roundworm (Toxocara canis)

Toxocara is probably the most underappreciated public health threat associated with dog waste. The CDC reports that approximately 14% of the U.S. population, roughly 45 million people, has been infected with Toxocara at some point. Most infections are asymptomatic, but in children, the consequences can be severe.

Toxocara eggs are shed in dog feces and become infectious in soil after 2-4 weeks of maturation. Once mature, the eggs are extraordinarily resilient. They can persist in soil for years.

When accidentally ingested (typically by children who play in contaminated soil and put their hands in their mouths), Toxocara larvae hatch in the intestines and migrate through body tissues. This causes two main syndromes:

• Visceral larva migrans (VLM): Larvae migrate to the liver, lungs, and other organs, causing fever, coughing, wheezing, and abdominal pain.
• Ocular larva migrans (OLM): Larvae migrate to the eye, potentially causing inflammation, vision loss, and in rare cases, blindness in the affected eye.

A study published in the American Journal of Tropical Medicine and Hygiene found that Toxocara seroprevalence was significantly higher in communities with poor pet waste management practices. The NIH has identified Toxocara as a “neglected parasitic infection” warranting increased public health attention.

The moist soil conditions throughout Western Washington are conducive to Toxocara egg survival. Properties in neighborhoods with mature trees and shaded yards, common throughout Gig Harbor’s Artondale area, Silverdale’s Ridgetop, and wooded lots in Port Orchard, may retain eggs longer due to reduced UV exposure. Ultraviolet light is one of the few natural mechanisms that degrades Toxocara eggs.

Hookworm (Ancylostoma caninum)

Hookworm is particularly insidious because you don’t need to ingest it to become infected. Hookworm larvae can penetrate intact human skin on contact with contaminated soil. Walking barefoot in an infested yard is enough.

Hookworm eggs in dog feces hatch into larvae in warm, moist soil within 1-2 days. These larvae actively seek out hosts. They literally move toward the warmth of nearby skin.

In humans, hookworm typically causes cutaneous larva migrans, which presents as intensely itchy, serpentine skin lesions that occur as larvae tunnel through the upper layers of skin. The condition is self-limiting but extremely uncomfortable and can last weeks.

Western Washington’s cooler temperatures slow hookworm larval development somewhat, but the consistently damp conditions from fall through spring provide adequate moisture for larval survival. Summer months, when soil warms and families spend more time barefoot outdoors, present the highest risk window.

Salmonella

Dogs can be asymptomatic carriers of Salmonella, shedding the bacteria in their feces without showing any signs of illness. This means even a healthy, well-cared-for dog can be depositing Salmonella in your yard every single day.

Salmonella spreads through contact with contaminated soil or surfaces. Dogs walking through contaminated areas can also transfer Salmonella to indoor surfaces via their paws.

Salmonellosis causes diarrhea, fever, and abdominal cramps, typically lasting 4-7 days. While most healthy adults recover without treatment, the CDC reports that Salmonella causes approximately 1.35 million infections, 26,500 hospitalizations, and 420 deaths in the United States annually.

Campylobacter

Often overlooked in discussions of pet waste pathogens, Campylobacter is actually one of the most common causes of bacterial gastroenteritis worldwide. Dogs, especially puppies, frequently carry and shed Campylobacter.

Campylobacter survives longer in cool, moist environments. A study in Applied and Environmental Microbiology demonstrated extended survival at temperatures below 15°C (59°F), which describes the majority of Western Washington’s year.

How long do pathogens survive in Pacific Northwest soil?

This is the question that changes minds. People assume rain “washes away” the problem or that waste breaks down quickly. In reality, the Pacific Northwest’s climate extends pathogen survival significantly compared to drier, warmer regions.

Here’s a summary based on published research:

Pathogen	Survival in PNW soil conditions
E. coli	Weeks to months
Giardia cysts	1-3+ months
Toxocara eggs	Months to years
Hookworm larvae	3-6 weeks (seasonal)
Salmonella	2-12 weeks
Campylobacter	2-4 weeks

The key takeaway: a pile of dog waste deposited in your Lakewood backyard in October may still pose a health risk when your kids start playing outside in April. The winter rains don’t sterilize it. They redistribute the pathogens.

Who’s most at risk?

While anyone can be affected by pathogens in dog waste, certain populations face significantly elevated risks.

Children under 5

Young children are the highest-risk group for several reasons:

• They play on the ground, in dirt, and in grass
• They frequently put their hands (and objects) in their mouths
• Their immune systems are still developing
• They’re more likely to be in close contact with contaminated soil

The CDC specifically identifies Toxocara as a concern for children, noting that playgrounds, sandboxes, and yards contaminated with dog feces are primary exposure sites. If your kids play in the backyard, whether in Tacoma, University Place, or Silverdale, regular pet feces removal is a real health precaution.

Immunocompromised individuals

People with weakened immune systems, including those undergoing chemotherapy, organ transplant recipients, individuals with HIV/AIDS, and elderly adults, are at heightened risk for severe illness from the pathogens found in pet waste. What might cause mild symptoms in a healthy adult can cause life-threatening infections in immunocompromised individuals.

Pregnant women

Certain infections transmitted through animal waste can pose risks during pregnancy. While Toxoplasma is more commonly associated with cat feces, pregnant women should minimize contact with all animal waste as a precaution.

Other pets

Your dog isn’t just at risk from their own waste. They’re also at risk from waste left by other dogs. Parks, trails, and shared green spaces where waste isn’t consistently removed become transmission hotpoints for Giardia, parvovirus, and intestinal parasites.

The waterway connection: why your yard affects Puget Sound

Here’s where the story gets bigger than your backyard.

The Environmental Protection Agency (EPA) has classified pet waste as a nonpoint source pollutant, right alongside chemical fertilizers, oil, and pesticides. When rain falls on dog waste (which, in Western Washington, it does roughly 150-170 days per year), it carries fecal bacteria directly into the stormwater system.

Unlike sewage, which is treated before discharge, stormwater in most Western Washington communities flows directly into local waterways without treatment. That means the E. coli from dog waste in your yard in Tacoma can reach Commencement Bay tributaries. The Giardia from a pile in Illahee can wash into Sinclair Inlet. The pathogens from accumulated waste in a Puyallup neighborhood can find their way into local creeks and ultimately Puget Sound.

This isn’t theoretical. The Washington State Department of Ecology has identified fecal coliform bacteria as a leading cause of water quality impairment in Puget Sound and its tributaries. While agricultural runoff and failing septic systems are also contributors, the cumulative impact of pet waste from the region’s estimated 1.5+ million dogs is substantial.

The Tacoma-Pierce County Health Department’s “Scoop the Poop” initiative and similar programs run by the Kitsap Public Health District exist specifically because of this connection. They’ve tested local waterways and found fecal coliform levels that exceed safe limits, and genetic testing has confirmed that dog waste is a significant source.

The numbers

Consider this: the average dog produces approximately 274 pounds of waste per year (EPA estimate). With roughly 89.7 million pet dogs in the United States (American Pet Products Association, 2024), that’s an enormous volume of biohazardous material, much of which ends up in yards, parks, and eventually waterways.

In a county like Pierce (population ~900,000), even a conservative estimate of dog ownership suggests hundreds of thousands of dogs producing waste daily. If even 40% of that waste isn’t promptly removed, a figure consistent with national surveys, the cumulative environmental impact is significant.

The “it’ll decompose” myth

One of the most persistent misconceptions about dog waste is that it’s “natural” and will simply decompose and fertilize the lawn. This is wrong on multiple levels.

Dog waste is not fertilizer. Unlike cow or horse manure (from herbivores), dog waste comes from an omnivorous diet that produces highly acidic, pathogen-rich feces. Applying it to gardens or lawns is more likely to burn grass and contaminate soil than improve it.

Decomposition doesn’t equal sterilization. Even as waste visually breaks down, many pathogens, particularly Toxocara eggs and Giardia cysts, remain viable in the soil long after the visible waste has disappeared. You can’t see them, but they’re still there. We explored this topic further in our guide on dog poop dissolvers and why they fall short in PNW conditions.

The volume also exceeds what the environment can process. In natural ecosystems, wildlife waste is distributed across vast areas at low densities. Residential backyards, where one or more dogs deposit waste in a concentrated area day after day, experience pathogen loading that far exceeds the soil’s natural capacity to neutralize.

Why regular removal actually matters

When we talk about pet feces removal, the conversation usually starts with convenience and lawn aesthetics. But the strongest argument is medical.

Regular, thorough removal of pet waste from your yard:

• Breaks the transmission cycle of Toxocara, hookworm, and Giardia by removing eggs and cysts before they mature to infectious stages
• Reduces fecal coliform loading in your immediate environment and local waterways
• Protects children and vulnerable family members from soil-transmitted infections
• Decreases fly and pest populations that breed in and spread pathogens from waste
• Prevents accumulation that leads to lawn damage, odor problems, and tracking of contaminated soil indoors

A professional dog waste cleanup service performs systematic, scheduled removal, typically weekly, ensuring that waste doesn’t remain in your yard long enough for Toxocara eggs to reach the infectious stage (which requires 2-4 weeks of soil incubation). That’s a genuine public health measure, not just a convenience.

Dooky Squad provides residential service across our Pierce and Kitsap coverage area.

What the research says

The health claims in this article are supported by peer-reviewed and government sources, all linked throughout the text above. Key sources include:

• CDC Toxocariasis program, which identifies Toxocara as one of five “neglected parasitic infections” targeted for public health action. Seroprevalence studies indicate 13.9% of the U.S. population has antibodies to Toxocara.
• EPA nonpoint source pollution program, which classifies pet waste as a significant source of water pollution and fecal coliform contamination.
• NIH / National Library of Medicine, where multiple studies document the zoonotic transmission of parasites and bacteria from dog feces to humans, with particular attention to Toxocara, Giardia, and hookworm.
• Applied and Environmental Microbiology, which published research documenting 23 million fecal coliform bacteria per gram of dog waste and extended pathogen survival in cool, moist conditions.
• Washington State Department of Ecology water quality reports identifying fecal coliform contamination in Puget Sound tributaries, with pet waste identified as a contributing source.
• Tacoma-Pierce County Health Department public health guidance on pet waste management and its connection to local water quality.

Practical steps for pet owners

Understanding the risks is step one. Here’s what you can actually do about it.

Pick up immediately (when possible)

The gold standard is picking up waste immediately after your dog goes. This prevents pathogen maturation in soil and eliminates the exposure window entirely. If you’re walking your dog along the Ruston Way waterfront in Tacoma, the Gig Harbor waterfront, or through a neighborhood park in Lakewood, carry bags and clean up on the spot.

Don’t let waste accumulate

If immediate pickup isn’t realistic (and let’s be honest, it often isn’t for backyard use), the next best strategy is ensuring waste is removed at least weekly. This is where professional services earn their keep. Dooky Squad’s weekly service ensures waste never sits long enough for the most dangerous pathogens to reach peak infectiousness.

Wash hands after yard contact

Especially important for children. After playing in the yard, gardening, or any soil contact, thorough handwashing with soap and water is essential. This simple practice dramatically reduces the risk of ingesting soil-transmitted pathogens.

Keep dogs on preventive parasite treatment

Regular deworming and parasite prevention for your dogs reduces the pathogen load in their waste. Consult your veterinarian about appropriate preventive treatments. This is especially important in the Pacific Northwest, where environmental conditions favor parasite transmission.

Don’t compost dog waste for garden use

Home composting systems typically don’t reach temperatures sufficient to kill Toxocara eggs (which require sustained temperatures above 158°F). Dog waste compost should never be used on food gardens or in areas where children play.

Frequently asked questions

How long does dog poop take to decompose in the Pacific Northwest?

In Western Washington’s cool, moist climate, dog waste can take 6-12 weeks or longer to visually decompose. However, the pathogens within the waste, particularly Toxocara eggs and Giardia cysts, can survive in soil for months to years after the visible waste has disappeared. Rain accelerates the physical breakdown of waste but disperses pathogens into surrounding soil and waterways rather than eliminating them.

Can dog waste make my child sick?

Yes. The CDC identifies children under 5 as the highest-risk group for soil-transmitted infections from pet waste, particularly Toxocara (roundworm). Children who play on contaminated ground and put their hands in their mouths can ingest parasite eggs and bacteria. Toxocara infection can cause fever, coughing, abdominal pain, and in rare cases, vision loss. Regular removal of waste from yards and play areas is the most effective prevention.

Does rain wash away the bacteria in dog poop?

No. Rain makes the problem worse. Rather than sterilizing waste, rainfall dissolves and disperses pathogens into surrounding soil and washes them into stormwater drains, which in most Western Washington communities flow untreated into local waterways. The EPA classifies pet waste as a nonpoint source pollutant specifically because of this stormwater contamination pathway.

How often should pet waste be removed for health purposes?

Weekly removal is the minimum recommended frequency for most households with dogs. This timeline is based on the Toxocara lifecycle. Eggs require 2-4 weeks in soil to become infectious, so weekly removal ensures most eggs are collected before reaching the infectious stage. Households with multiple dogs, children, or immunocompromised family members may benefit from twice-weekly service.

Is dog waste really classified as a pollutant?

Yes. The EPA classifies pet waste as a nonpoint source pollutant in the same category as herbicides, insecticides, oil, and other chemical contaminants. This classification reflects the documented impact of pet waste on water quality, particularly fecal coliform contamination of surface waters and groundwater.

Can I get hookworm from my backyard?

Yes, it is possible. Hookworm larvae develop in warm, moist soil contaminated with dog feces and can penetrate human skin on direct contact. Walking barefoot in a yard where infected dogs have defecated is the primary transmission route. In Western Washington, the risk is highest during warmer months (June-September) when soil temperatures support larval development and people are more likely to be barefoot outdoors.