What is Lepto?
Leptospirosis, often called Lepto, is an infection of bacterial spirochetes. Dogs acquire this when subspecies of the Leptopsira interrogans penetrate the skin and spread through the body by way of the bloodstream.
Where would my dog pick up Lepto?
Your dog is most likely to encounter this bacterium from wildlife or other infected dogs. The bacteria can live in infected water, soil or mud and is most prevalent in muddy areas with stagnant surface water frequented by wildlife. Infection can also occur if your dog comes into contact with urine from an infected animal. Dogs that frequent wooded areas and dogs that live on or near farms are at an increased risk of acquiring infection. Also, dogs that have spent time in a kennel are at risk.
What does Lepto Do?
According to an article on PetMD, Lepospirosis is described this way:
Leptospires spread throughout the entire body, reproducing in the liver, kidneys, central nervous system, eyes, and the reproductive system. Soon after initial infection, fever and bacterial infection of the blood develop, but these symptoms soon resolve with the reactive increase of antibodies, which clear the spirochetes from most of the system. The extent to which the bacteria affect the organs will depend on your dog’s immune system and ability to eradicate the infection fully. Even then, Leptospira spirochetes can remain in the kidneys, reproducing there and infecting the urine. Infection of the liver or kidneys can be fatal for animals if the infection progresses, causing severe damage to these organs. Younger animals with less developed immune systems are at the highest risk for severe complications. PetMD
You can read the rest of the PetMD article to learn about common symptoms. Stonebridge Kennels highly recommends the Lepto (Leptospirosis) vaccination for your dog.