In the last few months there have been several cases of Canine Leptospirosis reported to the State of California Department of Public Health by small animal veterinarians. In these reports, most have a common history of visiting dog parks, but the significance is unclear. Dogs are typically exposed to leptospirosis through infected water or soil, or from coming into direct contact with urine from an infected animal. Hunting dogs and dogs that live near wooded or wild areas are at an increased risk. It is important to know that many wild and domesticated species can be affected by this disease and that the disease is zoonotic. That means that humans can acquire the disease from animals. In this recent outbreak no human cases have been reported.
Leptospirosis is a spirochete bacterium that is transmitted through the urine of an infected animal. It can survive outside the host in damp environments and has the ability to penetrate the skin to gain access to the bloodstream. In the body it reproduces in the liver, kidneys, central nervous system and eyes. Initial infection consists of fever and bacteremia, but these signs quickly resolve as the immune system clears most of the spirochetes from the body. At this point, the extent to which this bacterium damages the organs will depend on your dog’s immune system and its ability to eradicate the infection completely or not. Even then, the organism can remain in the kidneys, reproducing and infecting the urine without the dog showing any signs of illness. In some cases, infection of the liver or kidneys can be fatal if severe organ damage occurs. Younger animals with less developed immune systems are at the highest risk.
The most common method of transmission from pet to human is through direct or indirect contact with contaminated animal urine. The bacteria can enter the body through broken skin, mucous membranes, nose or eyes. Leptospirosis is rarely spread from human to human. Common human symptoms are similar to flu and sometimes eye pain and redness is present. Most human infection is mild and self-limiting but severe illness and death can occur. Immune compromised and young individuals are at higher risk.
Please ask your veterinarian for more information about Leptospirosis. Some geographic areas pose a higher risk than others. A vaccination for the prevention of the infection is available. Your veterinarian can advise you on the availability and usefulness of this vaccine.