Canine leptospirosis: Epidemiology, pathogenesis, and diagnosis

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.