Leptospirosis, or “Lepto” for short, is a bacterial organism that dogs and other mammals (including humans) can get from contact with infected water or urine. This bacteria can infect many different organ systems, including most commonly the kidneys and liver. This disease is one of the most common causes of acute kidney failure in young dogs. Acute kidney failure requires very intensive and expensive care to attempt to treat, and can often be fatal in severe infections, particularly in younger dogs.

This bacteria is prevalent in the environment, and appears to thrive best in wet conditions (such as after heavy rains) or near bodies of water.  It is spread by rodents and other wildlife species, which are called “reservoir animals”. These reservoir animals spread the bacteria, but often do not become ill themselves.  Instead, the bacteria takes up residence in their kidneys, and when they urinate, they contaminate the environment with the bacteria. 

Pets can become infected with Lepto through wading, swimming, or drinking contaminated water.  Both dogs and humans can also become infected by direct contact with urine of an infected animal.  Because of the way it is transmitted, pets who spend a large portion of their time outside, especially near water that is frequented by wildlife/rodents, are at the highest risk of becoming infected. AAHA vaccination guidelines recommend vaccinating for Lepto not earlier than 12 weeks of age, with a second dose 2-4 weeks later.  Annual vaccination is recommended based on risk of exposure.