The spiral-shaped bacteria, carried in the urine of infected animals, will have washed into ponds and lakes, where the water still holds just the right amount of summer warmth for them to thrive. The bacteria then enter the mucous membranes — eyes, nose, and other tender areas — of dogs who swim.
Sick dogs may experience fever, vomiting, abdominal pain, diarrhea, loss of appetite, and muscle pain — or they may show no symptoms. Meanwhile, the bacteria make their way into the bloodstream, then to the liver and kidneys.
“It takes about a week to run through the body,” says Joseph W. Bartges, DVM, of the University of Tennessee College of Veterinary Medicine. Even after treatment with antibiotics, dogs may need kidney care for the rest of their lives. In addition, “It can be passed to humans through their dogs’ urine,” Bartges says, “but it most likely will cause only flu-like symptoms.”
Outbreaks have stepped up in the Northeast, Midwest, Mid-South and West Coast. In 2005, 29 cases were reported within five months in western Washington, and six of those dogs died.
“Leptospirosis is being talked about as a re-emerging condition, but it certainly has been around a long time,” says Bartges, who recommends dogs get vaccinated.