Epidemiological and Molecular Patterns of Leptospirosis in Dogs in the US

George E. Moore, DVM, Ph.D. (D08CA-500)


Leptospirosis is an often fatal kidney or liver disease caused by bacteria in the genus Leptospira. The disease is transmitted by exposure to urine from an infected animal, usually wildlife, and its occurrence in dogs has increased in the past 10 to 20 years.

Funded by Morris Animal Foundation, researchers from Purdue University are investigating the frequency and geographical range of leptospirosis in dogs in the United States. They have mapped the geographical range of leptospirosis using more than 40,000 samples submitted to a commercial laboratory for testing over a seven-year period. Using this map, they have identified significant regional and temporal outbreaks of the disease in the United States. In addition to the known seasonal increase in the fall (thought to be attributable to increased movement and activity of infected wildlife, such as raccoons), researchers have also found a marked increase of the disease in toy breeds, likely because of lack of vaccination due to perceived lower risk of exposure in these breeds.

The research team has also evaluated the performance of several available tests designed to detect canine leptospirosis and have discovered that some tests give false positive results, with 10 to 15 percent of uninfected dogs being falsely identified as positive for Leptospira infection. This indicates the need for better diagnostic tools to identify infected dogs.

The researchers continue to try and identify specific strains of Leptospira that pose the greatest risk to dogs. To increase practitioner awareness and survival rates, Dr. George Moore, the lead investigator, has conducted several educational meetings with veterinarians to help improve detection of and treatment for this potentially fatal disease.