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How Long Does Dog Poop Take To Decompose?

When a dog does his potty business outdoors, a practice that is almost universal for dog owners across the country, our first tendency is to scoop up that poop immediately and discard it.

This is perfectly natural.

Dog poop can be a real eyesore in your backyard, and if you want to enjoy that outdoor space without worrying about stepping in a surprise it is vital that you remove all signs of that poop from your yard.

But did you know that dog poop will actually decompose after a period of nine weeks?

It’s true.

What’s more, that decomposed or biodegradable poop actually makes for good—and free—fertilizer that could help make your yard and garden even greener and healthier, while limiting the amount of dog feces that is piling up at your local dump.

In this article, we will—for lack of a better phrase—take a closer look at dog poop and its biodegradability.

We will also offer a timeline spelling out just how long it takes for dog poop to decompose.

How Long Does Dog Poop Take to Decompose?

If you have a small yard—or no yard at all—you are probably accustomed to picking up your dog’s “business” shortly after the offense.

But what if you had a very large property—several acres or more?

And what if your dog was free to roam throughout this very large outdoor space?

Would you really go hunting for every surprise he left you, scouring your land for any sign of poop?

If you would, you’d better be prepared to search for several hours—you may even have to give up your job!

Of course, we say this in jest.

Most homeowners with large swaths of land and a dog with free reign would reasonably leave the cleanup process to Mother Nature, allowing the dog poop to simply break down into its original elements, just as it does in the wild for the many animals that inhabit those spaces.

Factors that Determine the Speed of Decomposition

So just how long does it take for dog poop to decompose and return to nature?

And what are the factors that determine this timeline?

Let’s tackle the second of these questions first.

There are actually a couple of factors that could either slow or speed up the process of decomposition.

Some of these factors include:

  • Diet.  The time at which dog poop decomposes can actually be influenced by the type of food your dog consumes.  A diet that is high in grains and vegetables will produce feces that can decompose rather quickly.  These types of food are less complex in their makeup, and thus take less time to break down.  On the other side of the coin, dogs that eat mostly animal protein will produce poop that takes a bit longer to fully degrade.  Proteins are very complex and they rely on certain enzymes to fully break them down.
  • Climate and Weather.   While diet can play a minor role in the speed of decomposition, climate and weather can play a major role.  For example, decomposition takes significantly longer in very cold climates.  In areas where the temperature regularly drops below the freezing point, the dog poop itself will actually freeze, which stalls the entire process of decomp. Moreover, when poop becomes buried beneath the snow, it can often continue to be preserved until the next thaw.  Naturally, this phenomenon will stall its ability to degrade and the timetable is obviously extended—sometimes for up to a year.  In warm climates, conversely, the speed of decomposition can actually be increased.  Places that have warm to hot summers are ideal environments for degradability, as the heat and energy from the sun actually lend a hand in the process.  In these places, with this type of hot weather, full dog poop decomposition can actually take place in a matter of weeks.

How Long Does Dog Poop Take to Decompose:  The Process

As you can see, there are several factors that can slow—or speed up—the rate of decomposition for dog poop.

But assuming the ideal environmental and climatic conditions, just how long will that poop take to decompose?

Well, according to experts, the process can occur in as little as nine weeks.

Of course, having dog poop lie around on your nice backyard grass for 9 weeks or more is not very aesthetically or nasally pleasing—just the opposite.

Even more, experts say that prior to decomposition, allowing dog poop to sit on your grass could be very harmful to your yard and your pet.

The acidic nature and chemicals in feces can actually damage your yard over time, causing brown spots and affecting the soil underneath.

Moreover, parasite larvae in poop can produce worms and other parasites in your pooch.

For these reasons,  you should remove the dog poop from your lawn and place it in a compost pile—a pile that is far enough away from your home and backyard entertainment amenities so as to prevent any unpleasant sights or aromas.

Below we will outline the week-by-week progress of the typical 9-week decomposition of dog poop, explaining the biological processes that are happening at each stage.

Remember, this 9-week timetable only holds true in the most ideal conditions, meaning your experience at home may vary in terms of time.

Week 1—The Turd Has Landed

In the first few days after your dog has pooped, there are several forces at work that are essentially initiating the decomposition process.

Without being too gross or descriptive, this new pile of excrement is teeming with fecal bacteria that actually feed on the poop, helping to break it down and degrade.

It is estimated that the average dog craps out twice as many coliform fecal bacteria as humans.

Some of these may actually contribute to worm and parasite larvae that could later cause intestinal problems for your pooch.

In days 1-4, the poop may not take on any noticeable change in size or appearance, but by the time you get to the beginning of week 2 there are numerous visible signs that the environment is changing it.

Weeks 2-3—Same Size, New Look

By the time you start week number two, the overall size of the feces pile will probably remain constant, but its appearance will gradually begin to change.

Of course, in very warm environments, this change will happen much more quickly, as the heat of the sun rapidly dries it out and evaporates the moisture, ultimately changing the color of the poop from brown to black due to oxidation.

During weeks 2-3, the aforementioned bacteria in the turd is hard at work.

While these critters cannot be seen with the naked eye, they are actively degrading the poop as they feed and reproduce very rapidly.

While the lion-share of this bacteria is mostly benign, some, like E-coli and salmonella, could contain illness-producing properties if accidentally ingested by humans or animals.

By mid-to-late week 3, white mold may begin to form on the surface of the dog poop.

Because the majority of that poop actually consists of water, it makes for a perfect breeding ground for various types of molds and fungi.

Weeks 4-5—Watch Out for Larvae

During weeks four and five the dog poop will grow whiter in appearance as it becomes fully engulfed in mold.

It also begins to shrink slightly in size as the bacteria breaks it down.

This is also the time when any parasitic eggs that were passed begin to produce their infected larvae, which can sit in a hard shell on the poop for weeks.

This larvae can be picked up by fleas or mosquitos, and if your dog is later bitten by one of these infected insects, the larvae can then hatch inside of them leading to worms.

Infected larvae can also be passed into the soil and infect your dog that way.

This is one of the main reasons why poop should be kept away from your dog if possible.

Weeks 6-7-8—Ready, Set, GO

It is in weeks six, seven and eight that the decomposition process really goes into overdrive.

The dog poop begins to shrink dramatically during this stage with every passing week, and the poop turns almost completely white and has a furry-like appearance from the mold.

Pathogens are in high gear during these weeks, so it is vital you keep kids away from the contaminated yard so as to not put them at risk.

By the start of week 8 the poop is measurably smaller and barely recognizable from its week 1 appearance.

Week 9-Poof It’s Gone

By the end of week nine, the bacteria and environmental elements responsible for decomposition have finished their job, leaving little to nothing to show for it.

The spot of grass on which the poop sat is now empty and brown—brown from the chemicals and acids in the feces.

On the plus side, the enzymes in the bacteria and fungi have now reduced the once prominent piece of waste on your backyard lawn into its primary elements—oxygen, carbon, nitrogen, etc.—essentially giving the poop back to nature.

So how long does dog poop take to decompose? 

In perfect warm-environment conditions, that poop can be reduced to nothing after a full nine weeks. 

Bacteria, most of which is harmless (with some notable exceptions), along with various species of mold and fungi, have, in just 9 weeks, performed the basic steps that are required for natural decomposition.

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