Leptospirosis Cases Increase, Website Launched to Educate Industry, Consumers

Veterinarians across the country have reported an increasing number of leptospirosis cases this summer with at least five reported fatalities. Fort Dodge launched a website on July 27, 2004, to educate veterinarians and dog owners about vaccines with a section designated to leptospirosis, the most widespread zoonosis, according to the Centers for Disease Control.

“This is a nationally relevant disease,” said Ken Harkin, DVM, DACVIM, assistant professor at Kansas State University, who has studied the disease since 1991. Harkin, who is currently treating three dogs with leptospirosis, said that between 5 percent and 10 percent of dogs exposed to leptospirosis contract the disease. He added that many veterinarians stopped using the DA2PPL for annual vaccinations over the last five to 10 years because of possible adverse reactions caused by the leptospiral component.

“I can’t remember a time when we had three confirmed cases,” said Harkin, who hesitates to draw a direct correlation between a decrease in the use of vaccines and the increased incidence of leptospirosis. Instead he points to a variety of reasons, including an unusually wet summer as the most likely culprit. Leptospira bacteria thrive in stagnant pools and it is usually reported in spring, summer and fall. It is carried by rodents, raccoons and squirrels, and some veterinarians attribute the rise in leptospirosis cases in urban areas with rodent problems.

Early clinical signs of leptospirosis, which can be transmitted to humans through contact with urine, include depression, anorexia and joint or muscle pain. Astute owners who notice early warning signs in their pets, such as excessive drinking and urination, and bring pets to veterinarians quickly may see clear blood work. But that can change drastically within 24 hours, Harkin said, and many infected dogs that are not treated early enough suffer from renal failure. Veterinarians and dog owners can contract the disease through broken skin and if urine is splashed in the eyes. The disease can also penetrate intact skin, which puts veterinarians and home owners at risk, Harkin said.

Treatment options typically include intravenous ampicillin until vomiting has stopped, then oral administration of doxycyclin, Harkin said. Most dogs have an 80 percent to 90 percent recovery rate, though some are left with chronic kidney failure. Harkin hesitates to advise vaccinations unless dogs are raised on farms, used for frequent hunting or swimming, but he does encourage veterinarians to discuss leptospirosis with clients so that pet owners can weigh the pros and cons of vaccination and watch for clinical signs of the disease. “If you have a dog present with acute renal failure, really think of leptospirosis,” Harkin urged.