How many times have you come in close contact with a horse? You’ve probably lost count, right? How many times have you come in close contact with a sick horse? One with a cough, some nasal discharge, or just an infected wound, perhaps. Probably still more than a few. But how often, when caring for a sick horse, do you take the same personal care precautions—such as washing your hands or wearing gloves or a mask—you would when nursing a sick human? For many owners, probably rarely or never. And this lack of protection could put you at risk for life-threatening infections.

Case in point: The Morbidity and Mortality Weekly Report recently reported that, in March, a 71-year-old woman from King County, Washington, died following exposure to a sick horse. The horse had a history of mucopurulent (containing mucus and pus) discharge from the eyes and nose and was actively being treated with an antibiotic. Cultures from the victim (who developed symptoms consistent with an upper respiratory infection, followed by vomiting and diarrhea, and was ultimately found unconscious before she died at a hospital), the sick horse, and two apparently healthy horses residing in the same barn all tested positive for the bacterium Streptococcus equi spp zooepidemicus.

Despite this recent case, the number of humans that develop infections from S. equi spp zooepidemicus is very small considering the high contact rate between humans and horses, either healthy or sick, that harbor that bacterium.