Photo by Jessica Walliser

Every Sunday morning for the past eight years, I’ve co-hosted a radio program called “The Organic Gardeners” on KDKA Radio in Pittsburgh. We spend an hour every week answering gardening questions from callers and discussing all the latest gardening trends. Over the years, we’ve gotten a lot of unusual questions and some have been asked multiple times. When we get repeat calls, I always assume there must be a lot of folks out there wondering the exact same thing.

I get asked one question in particular on a fairly regular basis: “Why can’t I add dog waste to my compost pile?” Just incase you’ve been wondering the same thing, here’s the answer…

Doggie doo is not something you ever want to add to your compost pile. While it might seem that Fido leaves a lot of organic matter behind, it’s organic matter that could contain multiple parasites (including dog roundworm, Toxocara canis, which survives the heat produced in a compost pile and can infect humans) and other pathogens.

Inevitably the caller than asks, “Doesn’t cow manure have pathogens, too?” The short answer is yes, of course. There are pathogens in all excrement, but the diets and lifestyles of canines and cows are very different.

First and foremost, canines are carnivorous by nature, while cows and horses are not. The digestive systems of animals that consume meat-based diets are filled with different organisms than those that consume a vegetable-based diet. The flora that resides in the gut of a meat-eating animal, like a dog or cat, can cause skin and digestive infections in humans and may contain parasitic worms. Many of these organisms can survive the composting process and can be transferred to humans who handle the compost or who eat any vegetables that come in contact with it.

That’s not to say that animals with vegetable-based diets don’t carry dangerous pathogens, too. They certainly do—E. coli and Salmonella, for instance. It’s just that some pathogens break down in the compost pile while others don’t. When handling manure of any sort, be sure to wear gloves and wash well when you are finished. 

Excrement from all carnivorous animals (including dogs, cats and people) should be kept out of the compost pile. This is especially true if you plan to use the resulting compost on your garden.

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