The deadliest feature of Hurricane Sandy was not the wind and rain, but water from the storm surge. The storm surge was so massive it brought water into the lobby of The Animal Medical Center, but my basement, prone to flooding during a heavy rain, stayed dry.

The severe flooding has displaced families, ruined homes and washed away cars. Flooding can also make you sick when it contains bacteria, viruses, and parasites from sewage. Severe flooding can also make your dog sick by providing ideal conditions for a bacteria known as leptospira. It rarely affects humans, but at The Animal Medical Center we see several serious cases of leptospirosis in dogs each year. Recently, leptospirosis in outdoor cats has been reported.

Fall hurricane season provides an optimal situation for leptospirosis to occur. Even without a hurricane, cases are more common in the spring and fall. Several different varieties of leptospira bacteria are responsible for illness, but all are considered waterborne illnesses, explaining why flooding increases the risk of contracting it. Rats are considered the major reservoir of leptospira bacteria in urban areas such as New York City. Sandy’s flooding “displaced” rats from the subway tunnels, bringing rats and their leptospira bacteria into the city streets.

Because of the increasing interface between wildlife and suburbia, even dogs in flooded suburban areas are at risk for contracting leptospirosis carried by mammals other than rats, including deer, mice, skunks, raccoons, cattle, and rabbits.

Dogs infected with leptospira bacteria are lethargic, refuse to eat, and vomit. When veterinarians test the blood of these dogs, anemia, decreased blood clotting ability, kidney failure, and liver dysfunction were commonly found. In severe cases, the lungs also lost function. Leptospirosis is treatable with antibiotics, but severe cases of kidney failure may require intensive treatment, including dialysis.

• If your dog is sick and has been exposed to floodwaters, tell your veterinarian.
• Don’t let your dog walk in or drink water where flooding has occurred.
• Talk to your veterinarian about your dog’s need for the leptospirosis vaccine.
• Read The AMC’s post hurricane safety tips.