This infectious disease can affect all species (including humans). It is caused by 11 different species (known as serovars) of a bacterium that is shed in the urine and is able to survive in the environment for long periods of time. It is easily spread through contamination of water in rivers, ponds, lakes, streams, and even puddles in your yard if an infected animal has urinated there, or rainfall has washed the bacteria into the area. Once infected, dogs quickly become ill with symptoms that are secondary to kidney and liver failure, and even with aggressive treatment are unlikely to survive. This infection can cause the same devastating disease in humans, and is a public health concern. The best prevention for high risk dogs is vaccination initially with 2 injections 3-4 weeks apart, then yearly as an adult. If your dog frequently goes hunting or plays in puddles, ponds, streams, lakes, or rivers, please discuss having them vaccinated against Leptospirosis with one of our veterinarians. The vaccine does tend to have a higher risk of causing an allergic reaction, especially in small breed dogs, and thus it may not be appropriate for all dogs to receive.