Leptospirosis is a zoonotic bacterial disease of worldwide importance. The disease severity can range from asymptomatic infections to terminal illness and can affect a wide range of species. In some areas of the United States Leptospirosis is the most common cause of canine acute renal failure and should always be a differential. As this disease is zoonotic and can be spread by infected urine, it is of special importance in the veterinary field as an occupational health hazard and veterinarians should have the ability to educate their clients concerning risk factors. In the following case, a dog presented to the Cornell University Hospital for Animals with signs of renal failure and severe hepatopathy with icterus. The dog was tested for Leptospirosis using the microagglutination test for antibodies at the Cornell University Diagnostic Lab. However, due to the acute nature of the dog's disease, initial tests were negative for all serovars. Convalescent testing yielded a high positive titer for serovar L. Grippotyphosa. This paper addresses the various common presentations that should be employed to reduce the risk of human infection.