Dog: Leptospirosis

General information

Other common/scientific names: Leptospira


Leptospirosis is an infection caused by the bacteria Leptospira spp. It is a worldwide, zoonotic disease of domestic animals and wildlife. While there are many different subtypes of Leptospira in the world, Leptospira canicola, Leptospira icterohemorrhagiae, Leptospira grippotyphosa, Leptospira pomona and Leptospira bratislava cause disease in dogs. Raccoons, opossums and rodents plan an important role as reservoirs, especially in urban settings.


Leptospirosis is spread through the urine of infected animals. The Leptospira bacteria prefer stagnant or slow moving water and can live in moist, warm surroundings weeks to months. Dogs become infected through oral ingestion or direct contact of the infected urine or urine infected water. Leptospirosis can also be spread through bite wounds, reproductive secretions or ingestion of infected tissues. The incubation period is 4-12 days. These organisms spread quickly through the bloodstream to the kidneys and other organs including the liver causing life-threatening disease.

Cardinal symptom

  • Fever
  • Vomiting


Clinical signs will depend on the organ systems affected. However, 80-90% of dogs infected with Leptospira develop acute renal failure so clinical signs are usually consistent with kidney disease. They include fever, vomiting, depression, abdominal pain, lethargy, lack of appetite, joint pain and increased drinking.


Blood tests to determine a dog’s antibody levels to Leptospira can be performed. While a positive test might indicate an infection, a four-fold increase in the antibody level two to four weeks after the first test supports the diagnosis of leptospirosis. All dogs suspected of having leptospirosis should have a complete blood count (CBC), serum biochemistry and urinalysis performed to assess organ function. A fresh urine sample can be submitted for identification of the Leptospira bacteria. Other tests can be performed on the blood and urine to detect Leptospira DNA.


Because of the potential damage to the kidneys and liver, dogs with leptospirosis should be hospitalized for treatment. Antibiotics are administered to kill the bacteria. Intravenous fluids and electrolytes are used to reverse damage to the kidneys and liver. These dogs should be isolated during treatment to prevent the spread of disease.


If leptospirosis is diagnosed early and prompt, aggressive treatment is instituted, the prognosis is fair for a complete recovery. Young, unvaccinated dogs have a poorer chance of recovery. Leptospirosis is a serious life-threatening disease which can result in permanent kidney and liver damage.


Puppies should be vaccinated for leptospirosis beginning at 6 to 8 weeks of age and boostered every 2 to 4 weeks until 16 weeks of age. After the initial puppy series, an annual vaccine is recommended. Subsequent vaccination boosters are given annually depending on your veterinarian’s recommendation. Canine leptospirosis vaccination is most commonly included in a combined vaccine with canine parvovirus, canine parainfluenza, canine distemper, canine hepatitis and coronavirus.

Click here for more information on canine vaccinations.


Leptospirosis is a zoonotic disease meaning it is transmissible to humans. Dogs can shed the bacteria in their urine for up to three months after an infection. Following your veterinarian’s instructions regarding treatment of your dog and cleaning any surfaces with household bleach solution can reduce the likelihood of transmission.

Update version: 4/24/2014, © Copyright by
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