Leptospirosis in Dogs: Clinical Disease, Treatment and Preventative Measures

Leptospirosis in Dogs

Leptospira species can be spread from wildlife to dogs through direct contact with infected urine, contaminated water or soil. Leptospira can commonly be found in stagnant bodies of water, and as a result can pose an increased threat to dogs who swim, hunt or frequent marshy areas. Leptospirosis can lead to kidney failure, liver failure and additional concerns like pulmonary hemorrhage and uveitis.

Several types of Leptospira bacteria can be found throughout the world; however, only some have been noted to cause disease in dogs.

In canines, Leptospira interrogans and Leptospira kirschneri are the primary pathogens. More information regarding leptospires can be found here.

Once a dog comes in contact with leptospires through mucus membranes or broken skin,the bacteria replicate in the bloodstream before infecting other tissues.

During the initial phase of the disease, a patient’s immune system will start to respond by developing antibodies and will try to clear the infection. Early in the disease process patients may experience lethargy or fever.

As the bacteria spread to other organs, clinical signs may change and become more severe. Kidney and liver failure may occur in dogs significantly infected with leptospirosis which can lead to death. Bleeding complications may also be experienced in clinically affected canines.

Some animals may not become clinically ill, or may not stay ill for long, but can still harbor and shed leptospira through urine. These animals are called “carriers”.

Symptoms of Leptospirosis in Dogs

• Lethargy
• Fever
• Decreased appetite
• Vomiting
• Development of icterus (accumulation of bilirubin, which causes mucus membranes to be yellow in coloration) secondary to liver failure or hemorrhage
• Changes in urination or inability to produce urine
• Acute renal failure
• Uveitis (inflammation of the eye)
• Pulmonary hemorrhage and difficulty breathing
• Dehydration

Diagnosing Leptospirosis in Puppies and Dogs

If a patient is suspected to have lepto, there are several different diagnostic tests that will be recommended. Each test is valuable and provides veterinarians with very different types of information. A different test may be preferred during the different phases of infection.

Blood Profiles and Urinalysis

Basic blood profiles and urine evaluations are the initial tests run by veterinarians who have a suspicion of leptospirosis in their patients. Urine samples often reveal protein, glucose and increased red and white blood cells. The results of these tests vary between patients.

Below are some abnormalities that might be noticed with a chemistry evaluation and complete blood count.

• Elevated white blood cell counts
• Anemia
• Decreased platelets (thrombocytopenia)
• Elevated renal or liver values
• Electrolyte abnormalities 

SerologyTest

Serology tests utilize blood to identify antibodies against strains of leptospira species.

Titer test (MAT)

Titers are the most supported test. However, dogs early in the clinical disease may not have HIGH titer levels yet, leading to a negative test result. It is recommended to repeat a MAT 2-4 weeks after the initial test. Rising titer numbers are suggestive of recent infection.

ELISA Test

This particular test provides either positive or negative antibody results.

PCR Test

In patients with early signs of disease, a PCR test can be more beneficial than titers as it doesn’t rely on antibody levels. PCR tests are used to identify DNA belonging to leptospira.

Urine Cultures

Cultures using urine specimens can also be performed, but are not often utilized.

Treatment of Canine Leptospirosis

Dogs who are clinically ill and suspected of having leptospirosis generally need  an aggressive treatment plan ia hospital setting. Dogs will need to be placed on antibiotics, more specifically, doxycycline or penicillin derivatives.

Additionally, IV fluid therapy is necessary to help support the kidneys and facilitate urine production. Dogs impacted with lepto often will have a urinary catheter in place to help monitor urine production and prevent contamination of the environment.

Due to the infectious nature of lepto, dogs that are being treated should be separated from other patients and encouraged to eliminate in an isolated area. The area  where a positive lepto patient utilizes for a bathroom should be cleaned appropriately.

Zoonotic Potential

Leptospira is a bacterial pathogen that can be spread from mammals to humans. Due to the zoonotic potential of the disease, extreme caution should be made by Individuals handling dogs suspected of having lepto, or confirmed to have lepto. Safety measures can include wearing gloves, face masks and glasses to help protect themselves from possible contact with infectious agents found in urine.

How to Prevent Leptospirosis in Dogs

Fortunately, there is a vaccination available to help protect patients against leptospirosis. This vaccination is typically given in a two-part series, then administered annually.  Your veterinarian will help determine if this vaccination is appropriate for your companion.

Additionally, it is recommended to keep patients away from stagnant bodies of water including swamps, lakes and puddles. Drinking from slow-moving bodies of water should be discouraged. Ideally, pets should be walked in areas that are dry as they will be less likely to come into contact with this pathogen as it doesn’t survive long in dry environments.

Due to the spread of lepto generally occurring through wildlife, physical barriers like fences can help repel wildlife from your yard along with appropriate rodent control.