651-224-3038   •   1140 Grand Avenue, St. Paul, MN 55105


April 7, 2017

We have had several inquiries recently about whether to vaccinate dogs for Leptospirosis. Leptospirosis (aka lepto) is a bacterial infection that can cause acute liver and/or kidney infections. If diagnosed early it can be treated with antibiotics, but can cause serious and fatal infections or permanently damage these organs.


Several wildlife species carry lepto and pass it in their urine.  Runoff from rainstorms carries the bacteria to water sources (particularly small bodies of standing water), where dogs may be infected. Running water and large bodies of water are less concerning due to dilution. Less commonly, dogs can be exposed by eating prey animals or encountering their urine around nests or dens. It is typically more of a problem in rural or wilderness areas; however, since we have urban wildlife species (including mice, rats, and raccoons) in our area that can carry lepto it is not simply an urban vs rural concern. In fact, one of the only confirmed cases of leptospirosis we have seen here at the clinic was thought to be caused by exposure to rat urine during city sewer work that drove rats up into people’s yards.

There is a vaccine available for Leptospira, but this is a very frustrating vaccine to make recommendations about in our state. It has not historically been a high risk disease in Minnesota, but we do see cases from time to time.  A complicating factor is that there are hundreds of “serovars” (subtypes) of Leptospira, and while the handful that most commonly cause disease are covered by the vaccine, it is possible to be exposed to and infected by less common serovars. Simply put, in our area there is no black and white answer to whether to vaccinate. We do not routinely recommend across the board vaccination for all dogs. Aside from vaccination, controlling rodent populations and not feeding urban wildlife can also help lower the risk.


Dogs who go wilderness camping, hiking, to a cabin, etc. where they may swim or encounter wildlife are at higher risk and dogs who hunt vermin (rats or mice) are also at risk. In our experience, most people at our practice choose not to vaccinate and we have seen only two confirmed cases here at our clinic over the years. Several years ago, one of my neighbors was feeding raccoons in the alley and because of the increased raccoon activity in my neighborhood at the time I did choose to vaccinate for a few years until they moved. The vaccine has a reputation for having a higher incidence of vaccine reactions but I haven’t found this to be particularly true.
I’m sorry that this answer isn’t a definitive “yes” or “no” to the question of whether to vaccinate; it is just the frustrating nature of assessing risk for this disease. Let us know if you have more questions about leptospirosis.

-Karen Christopherson DVM CVA

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