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How Long Does Dog Poop Take to Decompose, Break down, and Biodegrade

We’ve all thought about it. Occasionally instead of picking up our dog’s poop, we’re tempted to leave the poop there to decompose. Then, just like any other dog owner, the question “how long does a dog poop take to decompose?” hits you.

If this has been your experience, then you’re on the right page. Here you’ll learn everything you need to know about how dog waste decomposes, breaks down, and biodegrades. On average, it takes about 9 weeks for dog poop to decompose.

Factors That Affect How Long It Takes Doggy Poop to Decompose

On average it takes about 9 weeks for dog poop to decompose. But, we need to address some additional factors that determine if the timeline is shorter or longer.


Size as a factor is just a basic principle. The larger the poop the longer it takes for it to decompose.


Decomposition starts within one week in humid and warmer climates. Warmer conditions are favorable to the bacteria that promote decomposition. An increase in the population of this bacteria leads to a shorter decomposition duration of about 9 weeks.

Conversely, colder climates render these fecal bacteria inactive, which in turn prolongs the process of fecal waste decomposition. In snowy conditions, the process stops altogether. Doggy waste can last up to 12 months in cold weather.

Dog’s Diet

Even in humans, whatever you eat determines what comes out. The same happens for dogs too. A meat-based diet results in doggy waste that takes longer to decompose. While a plant-based diet produces doggy waste that decomposes much faster.

However, deciding on your dog’s diet shouldn’t be based on decal decomposition. It’s always best to ask your vet for recommendations based on your dog’s individual needs.

The Stages of Dog Poop Decomposition

Although the factors above can cause different decomposition timelines, experts report that it can take up to 9 weeks under ideal environmental conditions. Here’s a week by week outline of the biological process.

How Long Does Dog Poop Take to Decompose

Week #1

Dogs poop remains pretty much the same during the first week. It might start to show slightly different coloration towards the end of the first week.

Even at this stage, the dog poop is already teeming with fecal bacteria and parasites. It’s estimated that an average freshly deposited dog waste contains twice as many fecal coliform bacteria as human waste.

Week #2 and #3

This is the stage where decomposition begins. There will be small changes to the physical appearance, although the size of the pile is roughly the same.

In warmer conditions, oxidation changes the color of poop from brown to black faster. This happens because the heat from the sun evaporates moisture from the poop.

During this period the bacteria population is actively degrading the poop pile. There are over 23 million fecal bacteria per one gram of dog poop. While most of these bacteria might be benign, some, like salmonella and E-coli, could pose a threat to humans and animals that accidentally ingest them.

Week #4 and #5

During this stage, the doop poop is engulfed in white mold and this readily gives it a whitish appearance. The bacteria at this point will begin to compromise the poop’s structural integrity. This is what results in the noticeable shrink in size of the poop pile.

Also, the parasitic eggs that were passed start to produce their larvae, which could remain in a hard case for weeks. These parasites can be picked up by vectors (mosquitoes or fleas). Any one of these vectors could infect your pooch with the larvae, the larvae would hatch inside them, then lead to worms.

This is a major reason why your dog should be kept away from its poop!

Week #6 and #7

The decomposition process goes into overdrive at this stage. The poop is completely covered in white mold and it starts releasing some spores.

These fungal spores can cause respiratory issues and allergies. Although the spores aren’t detrimental to humans, they could result in symptoms like runny nose, watery eyes, and difficulty breathing.

Week #8 and #9

During the 8th week, the poop would have shrunk to less than half of its original size, due to bacteria activity and continuous loss of water over time. The risk of danger, though not completely gone, has been reduced at this point.

At this point, the bacteria, parasites, and fungi have most likely spread around the immediate environment of the poop.

Therefore, it makes no difference disposing of the doggy poop now because your garden is already at risk of becoming contaminated.

In the 9th week the poop would have disappeared and all that’ll be left at the spot is an imprint. The poop has been reduced to its fundamental elements of oxygen, nitrogen, and carbon by the host of microbes that fed on it.

The grass underneath the dense fecal mass would be dead by now because sunlight hasn’t been getting to the plant. Though the poop itself has left the crime scene, the bacteria and parasites remain and could still cause some damages.

So, there you have it, a week-to-week breakdown of how long it does take dog poop to decompose.

How to Properly Dispose of Dog Poop

There are several ways to dispose of your doggy poop safely without causing harm to yourself, your dog, or the environment.

Used Plastic Bags

This is a convenient way of disposing of your dog poop, but it’s not the most eco-friendly option. All you have to do is reuse your old grocery bags to transport the poop to the landfill without contaminating anything else.

Biodegradable Bags

Biodegradable bags are a better option than normal grocery bags. They also help to transfer doggy waste to the landfill, though, in this case, the biodegradable bags disintegrate and allow the decal matter to decompose into the landfill environment.

Waste Collection Service

This is a great option especially for those who live in areas with lots of dog owners. All you have to do is drop your dog poop in a dog waste bin near your house. Then, a private waste removal service will come to deal with the collection of waste.

These waste collection agencies ensure that your waste is disposed of in an eco-friendly way. The cost of this service can be shared with other dog owners in the neighborhood to make it cheaper.


Instead of just getting rid of your pet poop you could convert it into compost. You could send the poop to a composting facility or do it in your own backyard. According to the U.S Department of Agriculture (USDA), you can speed up the composting process by adding a scoop of sawdust to every two shovelfuls of dog waste.

Compost obtained from dog fecal material isn’t suitable for planting vegetable gardens or fruits. However, it could be used for ornamental plants, potted plants, flower beds, and landscaping mulch.


The digester method helps to neutralize the pollutants in your dog’s waste and speed up the process of decomposition. So, you scoop the dog poop into a container with holes buried in your yard. Then you add enzymes and water to quicken the breakdown of the poop.

The digester option is also affected by climatic conditions. In warm and humid climates, it should take about 2 – 3 months for the original poop to decompose. But, in colder climates, the digester method isn’t ideal because the poop becomes frozen and decomposition is halted.

Also, if your yard is made up of clay soil, then the digester system isn’t for you. This is because clay soil has poor absorption properties, therefore liquified waste finds it difficult to get into the ground or does so at an extremely slow rate.

Flushing Dog Waste

You probably find this particular option strange, even though the toilet was practically designed to collect waste.

If it accepts human waste just fine, then there’s no problem with flushing down your pet’s waste as well. On the plus side, this is the most eco-friendly method of fecal waste disposal.

According to the U.S Environmental Protection Agency, flushing pet waste down the toilet and allowing the local sewage treatment plant to handle it is an effective way of preventing harmful infections.

Flushable bags can be used to scoop your dog’s poop, then be disposed of into the toilet carefully without contaminating the environment!

These biodegradable bags are ideal for flushing because they disintegrate upon coming into contact with water. It’s not advisable to throw them into the trash for this same reason. It’s important to note that flushable bags can still clog up the toilet if the plumbing isn’t adequate.

Give to Worms

If by some chance, as a dog owner, you happen to be interested in vermiculture as well, this option is ideal for you. Dog poop can be included in the worm bin alongside food scraps and other organic materials.

If you’re adding dog poop to vegetable waste, you’ll need to supplement with leaves and newspapers. This aids the breakdown by providing carbon because worms do not decompose dog food, they feed on it.

A pound of red worms can feast through half a pound of waste per day. Worms will yield fertilizers of their same body weight in waste per day. Note that if your dog has taken a dewormer, its poop can be harmful to worms in vermiculture. Also, don’t use dog waste fertilizer on edible plants.

How to Get Rid of Dog Poop in the Garden Without Scooping

Although it might not be difficult to pick up after your dogs in the park, it could be a hassle to deal with it in the yard. If so, you’ll be delighted to find out that there are ways to make it go away without having to get your hands dirty.

Agricultural Lime

Agricultural lime is made with powdered limestone and can be purchased from any gardening store. Agricultural lime removes moisture from the feces, offsets the smell, kills bacteria, and hastens the poop break down.

Warning, lime is very reactive and should be handled cautiously to avoid injury. Also, it could be damaging to your garden’s soil if used excessively.

Commercially Available Enzymes

Commercially available enzymes, also known as dissolvers, are designed to eliminate all bits of dog waste within a short period of time. They’re a safer alternative to agricultural limes. They can also take care of the foul smell because they are scented!

Examples of these enzymes are:

  • Lipase: breaks down fats, oils, and grease
  • Protease: breaks down proteins
  • Amylase: works on starch
  • Cellulose: effective on vegetable matter

How Dog Poop Affects the Environment

While it is true that to the naked eye dog poop disappears in the 9th week, what really happens is that the broken-down matter enters into the soil and sips into the channel of the local water supply. Over time, an accumulation of fecal matter will result in the pollution of streams, rivers, creeks, and other local waterways.

Doggy waste comes with a truckload of harmful bacteria, parasites, viruses, and many other diseases that can be detrimental to animals and humans. In addition to these microbes, dog waste harbors and transmits different varieties of worms, some of which pose a danger to humans.

Campylobacter bacteria, one of the fecal bacteria found in dog poop, can be especially dangerous to humans. It causes transient gastrointestinal discomfort in healthy adult humans. But, it can result in life-threatening infections in the elderly, infants, and people with compromised immune systems.

Some other bacteria present in dog poop include parvovirus, salmonella, and E.coli.

Cities with dog poop lying around are always at risk of being plagued with the prevalence of pests and rodents. Rodents, such as rats, eat dog poop and with rats come another set of problems for humans. Rat droppings and urine have been several types of harmful diseases like typhus, Lassa fever, leptospirosis, and salmonellosis.

As mentioned earlier, one gram of dog poop contains about 23 million fecal coliform bacteria. But, not all of them just stay on the ground, some of them are airborne bacteria and they pollute the atmosphere. In a recent study of air samples in Ohio, Michigan, Detroit, and Cleveland, 10 – 50% of airborne bacteria came from dog waste.

Types of Parasitic Worms Found in Dog Poop

Worms are common in dog waste and some of them can even infect humans. According to the CDC, 14 percent of humans test positive for roundworms (Toxocara).


They are intestinal parasites that are contracted by pets or humans by eating animal tissue infected by the larva, or by swallowing an infective egg.

Most dogs with roundworm infections are asymptomatic, but some may display symptoms such as diarrhea, vomiting, weight loss, and a pot-bellied appearance.

Report straight to your vet if you notice a spaghetti noodle-like appearance in your dog’s stool and vomit. Your vet will most likely take a fecal sample for further testing and diagnosis.


Whipworms are intestinal parasites, but they can’t affect humans. They are more likely to affect dogs than cats.

Whipworms are asymptomatic, but, in some cases, symptoms include anorexia, anemia, bloody stool, diarrhea, difficulty pooping, and belly pain. If you notice some of these symptoms, contact your vet for diagnosis.


Hookworms are usually found in the small intestines of animals. You and your pet could contract hookworms in three ways:

  • Ingestion of larvae from your surroundings
  • Larvae enter through the skin
  • Consumption of infected animal tissue

Symptoms of hookworms include weakness, lethargy, vomiting, anorexia, diarrhea, and dehydration. Adult pets are mostly asymptomatic, manifestation typically occurs in puppies and kittens. Hookworms will not be visible in your pet’s stool. So, when you notice these symptoms you need to see a vet and bring along a fecal sample.


Going through what has been discussed here doesn’t just provide an answer to the question, “how long does dog poop take to decompose?”

No matter how tired or lazy you are, make sure to pick up your dog’s poop in the yard at least twice a week. After reading, you should now be well aware of all the harmful substances in your dog’s poop during the decomposition process.

Now think about how much your beloved pooch poops and how much more danger you, your dog, and your immediate environment could be in if you don’t pick up the dog poop. Remember what they say – prevention is better than a cure!

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