Leptospirosis is a contagious disease affecting both animals and humans. In humans it is more commonly known as Weil`s disease.

It is caused by one of many Leptospira organisms which thrive in water. Infection by contact with infected urine or ingestion of urine-contaminated water is the most common means of transmission of the disease. Less common modes of infection include through the membranes of the eyes, abrasions or bite wounds, or ingestion of the flesh from infected animals such as rats, mice and voles.

Symptoms of disease.

During the first 4-12 days following infection with Leptospira, a sudden increase in temperature (103-105oF) may be seen along with depression, vomiting, loss of appetite, conjunctivitis, and non specific pain. Within 2 days body temperature may drop suddenly and there may be a dramatic increase in thirst. The urine may change colour and/or jaundice is often noticed and may be the only indication of disease.

In advanced cases of infection, profound depression, difficulty breathing, muscular tremors, vomiting and blood in diarrhoea are often observed as the infection progresses to include the liver, gastrointestinal system and other organs.


Leptospirosis treatment is a relatively complicated process comprising two main components - suppressing the Leptospira bacteria and treating secondary complications. This involves the use of specific antibiotics.

In advanced cases, supportive therapy to compensate for abnormal blood, kidney and liver function may be required. Therapy to restore urine production, kidney filtration and blood flow are essential to reversing kidney failure. In cases of severe liver disease, a decrease in clotting factors in the blood may lead to bleeding disorders requiring treatment by transfusion. Since Leptospirosis poses a risk to other animals and to humans, special precautions must be taken to prevent transmission of Leptospira from the dog to other animals and and to any humans in contact.

It is important to note that even after treatment and control of the active disease state, dogs continue to shed leptospira in their urine and therefore, may pose an infectious risk to other animals and to humans up to 3 months following infection.


Death can occur as a direct result of Leptospirosis. Death arising from secondary complications associated with progressive kidney and liver damage are common but may not occur for long periods following the initial disease.


Vaccines are available and protect against clinical disease associated with the 2 types of leptospira (L. icterohaemorrhagiae and L. canicola). Vaccination does not, however, prevent infection and development of a carrier state whereby the dog will be clinically normal for disease yet provide a source of contamination through the shedding of leptospira in its urine. Vaccination does not unfortunately protect against all types of Leptospira.