Leptospirosis is a serious bacterial infection that can affect both dogs and humans. Without prompt treatment with antibiotics, leptospirosis can cause severe organ damage and possibly death.

Leptospirosis symptoms are caused by Leptospira interrogans, a spiral-shaped bacteria known as a spirochete. Over 200 varieties (or serovars) of Leptospira interrogans have been identified. Leptospirosis vaccination only prevents the four most common serovars.

Contents at a Glance

Leptospirosis Transmission

Leptospirosis is spread when an open wound comes into contact with contaminated urine, wet soil, water (including drinking water) or vegetable matter. Leptospirosis is most common in warm climates.

Symptoms of Leptospirosis in Dogs

Leptospirosis spreads through the bloodstream and within a week of infection causes general symptoms of fever, lethargy, and pain. The bacteria reproduce in the kidneys, causing kidney inflammation and renal failure.

Other organs may also be damaged by leptospirosis, depending on which subtype of the bacteria is present. In addition to kidney damage, liver damage is also a common complication.

Symptoms of leptospirosis infection include:

  • abdominal pain
  • depression
  • diarrhea
  • excessive bleeding
  • excessive thirst
  • fever
  • jaundice
  • joint pain
  • loss of appetite
  • muscle pain
  • muscle stiffness
  • weakness.

Although leptospirosis can be life-threatening in any dog, younger dogs generally develop the most severe symptoms.

Diagnosing Leptospirosis

Veterinarians diagnose leptospirosis by performing a physical examination, noting symptom history and performing blood work. Blood work detects antibodies produced in response to leptospirosis: a result of 1:800 indicates the probability of the disease.

However, a positive diagnosis can only be made if the result of a second blood test, performed a month after the initial test, shows a fourfold increase in leptospirosis antibodies.

Leptospirosis vaccination administered within six months of the blood test can cause a false positive.

If needed, a kidney biopsy can diagnose leptospirosis. However, the procedure is invasive and not used on a regular basis.

Treating Leptospirosis with Antibiotics

Leptospirosis responds very well to penicillin-based antibiotics, the first stage in leptospirosis treatment. Once penicillin stops bacterial reproduction and infection in the bloodstream, a course of tetracycline antibiotics is used to clear leptospirosis from the kidneys. While penicillin and tetracycline are both antibiotics they can’t be used simultaneously.

While antibiotics fight leptospirosis, intravenous fluids are often necessary to maintain and support blood flow through the inflamed and damaged kidneys.

Treatment results vary. While leptospirosis is responsive to antibiotics, the prognosis is often dependant on the degree and severity of organ damage that occurs before treatment.

Killing Leptospirosis in the Environment

A dog that contracts leptospirosis will shed the virus in his urine. Contaminated areas can be disinfected with iodine products. To prevent human infection, use latex or rubber gloves when cleaning contaminated urine.

Leptospirosis Vaccinations

Leptospirosis vaccinations are part of standard DHLPP vaccinations (the L in DHLPP stands for leptospirosis) puppies receive. Unfortunately, leptospirosis vaccination only covers four of the 200 Leptospira interrogans serovars: canicola, pomona, grippotyphosa, and icterohaemorragiae.

However, there are also concerns that the leptospirosis portion of DHLPP vaccination is most likely to result in severe allergic reactions, such as life-threatening facial swelling and hives. If a dog does have a reaction to the DHLPP vaccination, the vaccine can be prepared without the leptospirosis component.

Although leptospirosis vaccination reduces disease severity, dogs that contract the bacteria will still be contagious.

Leptospirosis in Dogs

Leptospirosis in Dogs

Humans and Leptospirosis

Humans who contract leptospirosis usually develop flu-like symptoms. Like dogs, however, leptospirosis can produce life-threatening complications in humans, including damage to the kidneys, brain, liver, lungs, and heart. Leptospirosis in human responds well to antibiotic therapy.