Leptospirosis is a zoonotic disease that can pass from animals to humans. It is a bacterial disease that damages the liver and kidneys of dogs, sometimes resulting in renal failure and death. It is caused by a spirochete (spiral shaped bacterium) called a leptospire.
Leptospires live in fluids from infected animals, including urine, saliva, blood and milk. The disease is transmitted by direct contact with the fluids or with an infected animal. It is also transmitted by indirect contact such as vegetation, food and water, soil and bedding materials. Leptospires enter the body through mucous membranes or through breaks in the skin. The disease may be carried for years in animals without any apparent symptoms of the disease.
Any age, breed or sex of dog is susceptible to leptospirosis, although in general, young animals are more severely affected than adults. Large breed outdoor adult dogs are most commonly affected.
Leptospirosis can cause irreversible kidney damage, liver damage, uveitis (inflammation of the inner part of the eye), and damage to other organs.

What To Watch For
The first signs you might notice in your pet are flu-like symptoms. This may include several days of anorexia, vomiting, lethargy, depression and sometimes diarrhea or bloody urine. Other signs may include:
Chills and fever
Generalized muscle tenderness
Dehydration
Blood in the vomit or stool, bloody nose or widespread bruising
Jaundice
Labored breathing or coughing
Sudden lack of production of urine

Diagnosis
Your veterinarian will want to do a complete review of history and physical exam findings to develop a list of possible causes for your dog's illness. In order to make a definitive diagnosis of leptospirosis, however, various diagnostic tests may be recommended.
Leptospirosis test. A microscopic agglutination test (MAT) is the most frequently used serologic test for leptospirosis. It evaluates the presence of serum antibodies to leptospiral antigens.
General blood and urine tests
Kidney biopsy

Treatment
If the disease is caught in time, it can usually be treated successfully with penicillin and tetracycline drugs. However, those with renal failure may or may not recover, or may recover only partial renal function.
Animals with acute renal failure should be treated with appropriate fluid therapy.
Antibiotic therapy
Supportive care including hospitalization with intravenous fluids or blood transfusion.

Preventive Care
Prevention is available in the form of vaccinations, although they provide protection against serovars (subtypes) canicola and icterohaemorrhagiae. Despite this, immunization is recommended. New vaccines may provide a broader spectrum of protection.
Rodents are a potential source of infection for dogs, and rodent control, especially in kennels, is an important prevention method.
Minimize contact with wild animals because these animals are reservoirs of infection.
Isolate infected animals and maintain a clean environment