Leptospirosis is a bacteria with several different serotypes (serovars). Most mammals can be carriers and possible shedders of the bacteria while other animals will become clinically ill from the disease. The two most common serovars to infect dogs and to cause illness are Leptospirosis Grippotyphosa and Leptospirosis Pomona. This disease is relatively uncommon in cats. People can also become ill from exposure to the bacteria.
Urine contamination of standing water or moist soil can all lead to exposure and infection. Symptoms can vary but frequently include fever, vomiting, diarrhea, stiffness. As these symptoms occur with many other illnesses, prompt diagnosis can be difficult. The infection can rapidly progress to kidney and liver failure. History of recent exposure to standing water is helpful information. A rise in cases of leptospirosis is frequently seen in the warm, wet months or after a flood.
Anyone suspecting human exposure should contact their physician for instructions. For dogs, new vaccines are available that protect against multiple serovars of the bacteria. These do not prevent exposure or potential shedding of the bacteria in the urine, but do significantly help with clinical symptoms associated with infection. Vaccines reactions may occur as with any vaccine, but the newer vaccines seem to do so less frequently. Treatment with antibiotics can be curative if it is started before significant kidney or liver damage has occurred.
References: Iowa State University Zoonoses Protecting People and Their Pets 2013; 205
Tilley LP, Smith FWK Blackwell's Five-Minute Veterinary Consult Canine and Feline 2007; 808 - 809