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Updated: Apr 4

Leptospirosis – a Threat to Your Dog’s Health


3/27/17 (Update: Leptospirosis on the rise around the United States. Here is a recent report from New Jersey.)

Leptospirosis (“Lepto”) is a disease caused by a spiral-shaped bacteria that is found worldwide. Infections can affect people as well as many kinds of animals including dogs. Leptospirosis thrives in warm, moist areas (especially in stagnant water). While Arizona has not typically been associated with leptospirosis in the past, this is now our first significant outbreak (02/2017).

How is it Spread?

lepto source water

There are many ways that Leptospirosis can be contracted. Leptospirosis is shed in the urine of infected animals. A pet exposed to the urine of an infected animal will likely become infected. The most common source of infection is through drinking contaminated water. Slow moving or stagnant water in a warm environment is the ideal place for this bacteria to spread. Since Lepto is shed in the urine in high quantities, anything coming in contact with the urine will be a potential source of infection including vegetation, food, bedding and even the soil. Leptospirosis enters the body through cuts in the skin or through mucus membranes. Once a pet (or person) is infected, it takes 2-20 days to show symptoms of kidney or liver damage; however, some show no signs or symptoms but can still spread the bacteria to others.

How is it Diagnosed?

We look for Leptospirosis in cases of dogs that are sick with signs of fever, loss of appetite, muscle pain and stiffness, shaking, progressive weakness, and depression. Pets are often dehydrated as a result of this. Conjunctivitis may also be a common feature of Leptospirosis. Lab tests include urine tests, blood work, and specific serologic tests that detect it.

What are Treatment Options?

Since this is a bacteria, the use of antibiotics is a cornerstone of treatment. Fluid therapy is needed to sustain the liver and kidney function.

Is there a Vaccine I can use to Prevent this Disease in my Dog?

Yes. There have been vaccines available for many years to prevent Leptospirosis. But in recent years, the quality of vaccines has improved while the incidence of adverse effects has decreased. Vaccine reactions are uncommon with the current vaccine. We recommend this vaccine in all pets that might be exposed to water in parks, in the forest, or while camping, pets that are exposed to areas with unvaccinated dogs or wildlife, or in pets that travel to areas of the country where this is a more common problem. Proper vaccination requires a total of two vaccines about 3-4 weeks apart in the first year and then to have an annual booster yearly thereafter. Note: There are many strains of Leptospirosis and not every strain is covered with the currently available vaccines. The most common strains of Lepto, however, are part of the vaccines.

Besides Vaccinating, is there Anything Else I can do to Lower my Dog’s Risks?

Yes, there is. Make sure that your property is not a home to stagnant water (not only to lower the chance of exposure to Lepto, but to decrease attraction of mosquitoes as well). Congregating in areas with other dogs increases the risk of transmission of Lepto.

All “at-risk” dogs should be properly vaccinated.

Additional Resources on the Web:

Centers for Disease Control This site has answers to common questions of pet owners, including the human health risk posed by infected animals. A brief but thorough reference for pet owners.


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