Is it safe to use spearmint growing where dogs are walked?

Question:

spearmintI would like to use some spearmint growing in a neighbor’s landscape garden. Since the garden is next to the street where dogs are walked, a neighbor in my building (who is hyper cautious, I might add) advised against eating the mint because of concern that dogs may have peed on the plants at some point. I figured if I washed it thoroughly that it should be fine. (Also, it is far enough from the street that I doubt too many dogs made it that far!) Shouldn’t it be okay to use it as long as it’s washed well?

Answer:

Frank S. Wertheim, Extension Educator – Agriculture/Horticulture

The risks due to dog urine contact would be much less with time since the dog may have urinated there; fresh dog urine would be more likely to carry leptospirosis, a pathogen of people too. The risk of lepto isn’t high, given that most dogs have been vaccinated against it. Much bigger risks come from our lovely little rodents that love running around in dense plantings and are a lot more likely to carry pathogens (lepto, salmonella, etc.).  That said, neither is likely to be an important factor if the spearmint (or veggies) are well rinsed prior to use. 

Animal urine is a good source of nitrogen (in general), and less of an infectious disease issue than fecal material. Dog feces can contain pathogens that affect us, including dog roundworms (ascarids) and some species of tapeworms. Please see our Extension Bulletin #1002, Echinococcus granulosus canadensis (EG) in Maine Moose: Suggestions for Dog Owners. Keeping animals out of the garden is a good idea, and washing garden produce is an important help in general food safety.