Canine Leptospirosis: Epidemiology, Pathogenesis, and Diagnosis

CE Email comments/questions to [email protected], fax 800-556-3288, or log on to www.VetLearn.com Leptospirosis is a zoonotic disease of worldwide significance. It is caused by antigenically distinct serovars of the parasitic species Leptospira interrogans sensu lato, of which eight are most important to dogs and cats. The disease, which is caused by serovars most commonly incriminated (icterohaemorrhagiae and canicola) with cases of “classic” canine leptospirosis, has decreased greatly in prevalence with the development of commercial vaccines containing antigens from these serovars. However, reported clinical cases associated with other pathogenic serovars (particularly pomona, grippotyphosa, and bratislava) not included in these vaccines have seen a dramatic increase over the past 10 to 15 years. Serovars pomona and grippotyphosa have been associated with numerous cases of acute renal failure, and serovars bratislava, hardjo, and bataviae have been implicated in both hepatic and renal disease as well. Recent advances in diagnosing leptospirosis by using polymerase chain reaction have been described and may allow quicker, more accurate diagnosis of dogs affected with leptospirosis. are infected, they can develop severe clinical illness and shed organisms for shorter periods than the reservoir host. The most commonly incriminated serovars in canine leptospirosis have been canicola, icterohaemorrhagiae, pomona, bratislava, and grippotyphosa. Widespread use of bivalent vaccines produced in the 1980s that are serovar-specific for only canicola and icterohaemorrhagiae has resulted in a decreased prevalence of disease associated with those serovars. However, increased awareness of infections with serovars pomona, bratislava, and grippotyphosa has become apparent in the past 15 to 20 years. The predominance of disease associated with these latter serovars is likely associated with increasing exposure of unnatural hosts (e.g., dogs) to wild reservoir hosts in rural or suburCOMPENDIUM 606 August 2004 Canine Leptospirosis: Epidemiology, Pathogenesis, and Diagnosis John K. Sessions, DVM Craig E. Greene, DVM, MS, DACVIM (Internal Medicine, Neurology) University of Georgia L Now Online: Full-Text Articles and CE Testing at VetLearn.com