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February 23, 2023

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Leptospirosis in Dogs

Leptospirosis is a dangerous bacteria that your dog could pick up by coming in contact with contaminated water or soil. If your dog is affected by leptospirosis, it can develop life-threatening liver and kidney damage. The bacteria is also zoonotic (meaning people can pick it up from dogs). Luckily, there is a vaccine that can be administered to help protect your dog. Keep reading to learn more about leptospirosis. 

About the Organism

Leptospira organisms are spiral-shaped bacteria called spirochetes. There are 10 strains that can potentially infect our dogs. The strains can vary depending on where you are located. In Oregon, lepto is most commonly seen in the Willamette Valley and at the coast. However, in Central Oregon we also have the potential to see leptospirosis. 

Leptospirosis is more likely to occur in wet climates because the bacteria lives best in warm, slow-moving water. The bacteria can also contaminate soil for months once the water has dried. Wildlife commonly carry the infection. This can include raccoons and rats. It can also be carried by cattle.

How do dogs become infected?

Dogs become infected by leptospires when drinking contaminated water, if irritated or cut skin comes into contact with infected urine or water, or eating infected tissue. The organisms quickly spread through the bloodstream and within 7 days of infection they will inflame the blood vessels causing fever, abnormal bleeding, abnormal bruising and tissue swelling. By 2 weeks post-infection, the leptospires have invaded the kidneys where they continue to generate inflammation, pain, and potentially total kidney failure. Some strains also go to the liver and generate inflammation there, though the liver disease is generally not as severe as that of the kidney.

If the dog is able to survive the initial illness, they may develop a chronic form. This can include chronic kidney or liver disease or inflammation of the eyes (called uveitis). 

What symptoms to look for at home?

Symptoms can vary from dog to dog. If you notice abnormal bruising of the skin, abnormal swelling, increased water drinking, fatigue/lethargy, changes in eating, or vomiting, then you should take your dog to the veterinary clinic. Leptospirosis infections can look similar to many other diseases and usually require specific tests for a diagnosis. If your veterinarian suspects leptospirosis as a cause of your dog’s symptoms, then they will likely collect blood and/or urine samples for testing.

How is lepto treated?

The good news is that the type of lepto that affects dogs can be treated with antibiotics. It may take time for the antibiotics to work to clear the infection. If the infection is not diagnosed at the early stage, then some kidney and liver damage may not be reversible and may be fatal. Some dogs will require hospitalization for IV fluids, IV antibiotics, and other medications to keep them comfortable while the antibiotics have time to work. Recovery from infection depends on the extent of organ damage that has occurred. 

Since people can contract leptospirosis from dogs, it is important to take precautions (like wearing gloves and safety goggles) when handling urine of infected dogs. Lepto can also live in soil so it is important to be aware of environmental contamination. 


There is a vaccination against the most common strains of leptospirosis. It will reduce the severity of disease if your dog comes in contact with leptospires. The vaccine has improved over the past 10 years, so vaccine reactions are less common than they used to be. 

If you have any questions about leptospirosis or vaccination, please contact us.