A Fremont, California dog park was temporarily closed in response to concerns about canine leptospirosis after 4 reports of dogs contracting the disease, potentially associated with exposure at the park. It’s always hard to determine the source of exposure with lepto, but a park is certainly possible. We don’t understand a lot about how and where most dogs get exposed because it’s a somewhat challenging bug to track. Certainly, parks provide great mixing grounds for dogs and wildlife (the latter being the main reservoirs of the bacterium).

What to do with a potentially contaminated park area is a common question (without a good answer). Fremont Parks Supervisor Juan Barajas indicated to NBC Bay Area “that workers have briefly shut down the park and are working on extra sterilizations using diluted bleach on all the surfaces, including the astroturf. This is the first time the infection has been associated with the park and as a part of a new policy, there will be thorough cleanings and sterilizations four times a year.”

I appreciate the sentiment, but doubt this will do much to control disease spread. For one thing, you can’t effectively disinfect the outdoor environment. Bleach gets inactivated readily in the presence of organic debris (e.g. dirt). You can disinfect smooth surfaces and maybe the astroturf, but those aren’t likely the main problem. Leptospira bacteria get into the environment via urine of infected animals, predominantly wildlife. Even if you could sterilize the environment, if infected wildlife are present (which is almost certainly the case), contamination will recur very quickly. Thorough cleaning is never a bad idea, but I don’t expect this to do much to protect against lepto. The most important things that Fremont Parks can do are to spread the word about the potential risk of lepto and encourage dog owners to vaccinate their dogs against this nasty disease.