CHICAGO—Chicago veterinarians are warning about the rise of a potentially fatal infection called leptospirosis. Vets are seeing more dogs catch the bacteria, which, if left untreated, can spread to humans.
In the past, leptospirosis concerns were restricted to farms and kennels, and usually associated with tropical climates. Southern states have experienced lepto eruptions, but now northern states such as—Massachusetts, Michigan, New Jersey, New York, and Illinois are seeing more cases.
Dr. Natalie Marks, co-owner of Blum Animal Hospital on Chicago’s north side, says her practice has seen a dramatic increase in leptospirosis cases in 2014—eight infections this spring compared to the typical 1 to 3 a year. She says all types of dogs are at risk.
“We know that inherent risk factors all involve contaminated water, and they don’t have to be that classic hunting dog or active large breed dog to get this disease, which is so important for the public to realize,”Marks said.
“An English bulldog, to a toy poodle, to a golden retriever, to a Havanese. You name it we’ve had it.”
Most mammals can spread the infection through their urine, but for pets, lepto is primarily a canine concern (it is extremely rare in cats). The hearty bacteria can survive in soil or water without a host for months. According to Dr. Marks, Chicago’s recent snowy winter and wet spring, combined with the city’s growing rat problem provide the ideal environment for lepto to thrive.
“We’ve had the perfect storm of changes in Chicago to make this disease highly populous and unfortunately very easy for dogs to acquire in the city,” Marks said.
Rats are a classic carrier of leptospirosis, but researchers are now seeing more of the disease in raccoons. In April, a statement from Chicago veterinarians said that the biggest problem may be in the suburbs, “where dogs of all sizes and ages are coming in ever-closer contact with wildlife.”
Risk to Humans
Since the disease can spread to humans, its increase in pets also presents a public health risk.
“I used to work in Atlanta and there were cases of kids getting lepto from their dogs,” Marks said. “It’s a huge problem.”
According to the Centers for Disease Control (CDC), leptospirosis poses a wide range of symptoms—including fever, muscle aches, vomiting, and jaundice. Without antibiotic treatment, leptospirosis can lead to kidney damage, meningitis, liver failure, respiratory problems, and even death.
Once an infection takes hold, it may take time to spot. Symptoms can often be mistaken for other diseases and many vets may not think to screen for lepto. An animal may not exhibit any symptoms, but still excrete the bacteria.
There is a leptospirosis vaccine available but it is not part of the core essential group that includes rabies and distemper shots. Due to cost and complications related to vaccines, more dog owners are opting out of any shot that isn’t absolutely necessary, and some vets say this is one reason why the disease is returning in greater numbers.
Dogs that are not exposed to the outside world are fairly safe, but Dr. Marks strongly recommends the vaccine for pets that spend a lot of time outside and drink from communal water bowls. Although it provides some protection, Marks said vaccinated animals may still catch it.
“Even our vaccinated dogs are being exposed and unfortunately becoming positive for infection because the best vaccine that’s out there right now only covers four strains of bacteria. We now know that there’s over 180 different strains of leptospirosis,” she said.
The CDC says leptospirosis risk can be greatly reduced by avoiding contact with water that might be contaminated with animal urine, or eliminating contact with potentially infected animals. The agency advises protective clothing or footwear be worn by those exposed to contaminated water or soil.