Leptospirosis Study in Chicago


In a collaborative effort, several investigators from The Ohio State University College of Veterinary Medicine as well as MedVet Chicago partnered on the paper, “The Descriptive and Spatio-Temporal Analyses of 45 Canine Leptospirosis Cases from Chicago, 2015-2018.”

Amanda SmithPhD Candidate at The Ohio State University College of Veterinary Medicine is the lead investigator on the project, which found clusters of the bacterial infection occurring with surprising frequency. As the report indicates, this is bad news for unvaccinated dogs, but also potentially for people. Leptospirosis in zoonotic, which means people can get it too.

Lepto likes to live in water, large bodies of water or even puddles. Infected animals, from city rats to raccoons to skunks – even infected dogs, urinate in the water. Then a dog jumps into the puddle and later licks her paws or drinks water tainted with the infection from a retention pond, lake or any body of water. If that dog isn’t protected it’s likely the dog will pick up the infection. Some dogs show no symptoms – but being infected they continue to spread or shed the bacterial infections when they urinate in pond or puddle.

One symptom of lepto is actually more frequent urination, which could mean accidents in the house. If a person cleans up that accident without washing or a toddler touches it, and then hands go to mouth – a person can get sick, sometimes very sick. And some dogs also get very sick; death may even occur.

Results of Study

In this study, focused on Chicago, 29 percent of dogs died due to leptospirosis.

According to the Chicago leptospirosis study, the infection was reported more often where there are lots of dogs such as near dog parks. Unfortunately, there are many children who happen to live in these particular neighborhoods. In this study, June through August appear to be peak months, though even in Chicago (where it obviously gets very cold) lepto was identified from March through December.

Sadly, but predictably (due to not ready for prime time immune systems), 35 percent of the dogs with leptospirosis were 6-months or under. And among these sick puppies, only one was vaccinated

So, while vaccination is not a 100 percent protective, even dogs with the vaccine who get sick aren’t as likely to be hospitalized or hospitalized as long. Also, all vaccinated dogs aren’t contagious to the community.

There’s little doubt that at least, in part, what’s driving all this leptospirosis in Chicago (“the rattiest city”) and other major metro areas are, in fact, city rats.

For information about prevention and vaccination for leptospirosis, visit stoplepto.com or speak to your veterinarian.