Sunday, May 15, 2011

Composting Dog Poo?

Re-post: The original along with the comments were lost during maintenance issues this week.

When I wrote about my Outcome Metrics earlier this week, Voie de Vie asked why I wasn't composting the dog poo.

My original response was I didn't think it was safe to compost into plant fertilizer because only the manure from herbivores can be used.  But I wasn't certain so I promised research it.

Now that I've had some time to think about it and do a little research, I know that theory is not entirely correct.

Both Chicken Manure and Bat Guano are excellent compost for plants.  Since Bats and Chickens enjoy a large amount of bugs as well as plants in their diet, they are considered omnivores not herbivores.

So since Dogs are carnivores, does that make a difference?

Certainly Dog Poo can be composted.  Who hasn't seen an old pile of dog poo decomposing along a trail that someone left behind?  So the real question is: Can Dog Poo be composted into something that is useful for fertilizing food bearing plants?

Here are the articles I found useful:

This article from provides instructions for making a composter out of an old trash can, like we did for our fruit and veggie compost.  Bury it in the ground and add septic tank starter and water.  The dog poo composts quickly with this method but should not be used in the garden.

According to the University of Minnesota Extension Service, Dog (and Cat) Poo are a source of worms and parasites that can adversely affect human health.  You can read the details, but if you prefer not just take this gentle reminder to always wash your hands with soap and water.  However, Dog (and Cat) poo can be sterilized and composted into useful plant fertilizer if the heap exceeds 165 deg F (74 deg C) for at least 5 consecutive days.

This article was referenced in the article I listed first.  It suggests that composted dog poo is fine for ornamental plants but not for food bearing plants.  The testimonial is quite interesting.  He states he hasn't had to empty the composter in over 6 years.  If you wanted to use this method, the composter should be placed away from water and edible plants.

This article suggests dog poo can be used in a vermicomposting bin but should not be mixed with fruit or veggie scraps lest the worms revolt.  I'm not certain what a worm revolt would look like, but it can't be good.  It did mention that worm castings are a good fertilizer which is true for vegetarian worms.  However I did not see any references that indicate the health issues described in the UMN article are resolved.

Also HalfPint found this Dog Loo which looks like a commercial version of the in-ground composter described by CityFarmer and Plantea.

So it looks like Dog (and Cat) Poo can be turned into useful plant fertilizer if (and only if) you are able to ensure the appropriate temperature is reached and sustained during the composting process.

I am confident that our current composting process does not reach the required temperature.  If it does, it certainly is not maintained.  However, the in-ground composter is an interesting idea that will required more thought.

Thank you Voie de Vie.  I have enjoyed this little research project.  :-)


WonderWhyGal said...

um...I think I will continue to let my dog poo get dumped in the woods and leave the chicken, rabbit and alpaca poo for composting.

Great info!

Voie de Vie said...

Well, you're welcome, I think. I didn't know my question would launch a full-on pet poo discussion. :)

However, it is good to know. While I don't compost my cat poo (since it's part of curbside recycling), it's good info to keep on the back burner. So to speak.

Kathryn Ray said...

@VdV - it's interesting that cat poo is part of your city's recycling program. I haven't heard of that before.

Kate (KnitsInClass) said...

Having a dog who is very "productive" this was really interesting to read - I hadn't thought it was ever possible to compost pet waste, so it was interesting to see different theories and methods. Seriously considering the dog loo - thanks for the links!

Sessplantfertilizer Man said...

WOOOO O.O .OK man,first you freaked me out with composting dog feces,then you said bugs are apart of the plant's diet.LOl man wow i thought only bugs eat plants.I learned something today for sure.Not to mention the disadvantages and benefits of composting dog poo as plant fertilizer.