Leptospirosis – By: Dr. Cindy Krane
Leptospirosis – By: Dr. Cindy KraneDate: September 1, 2014
Leptospirosis is a bacterial disease initially causing fever, chills and flu like symptoms the progressing to severe, life threatening kidney or liver failure.
All breeds are susceptible to Leptospirosis with young to middle aged, active, large breed, male, outdoor dogs at higher risks of contracting the infection. The organism thrives in warm, humid and wet climates including South Florida.
Transmission can occur through both direct and indirect pathways. The bacteria resides in slow moving, stagnant water. The water becomes infected as rodents, fox, squirrels, skunk raccoons and opossums void in it. Dogs may contract the disease by coming into direct contact with infected urine, from bite wounds and ingesting affected tissues. Alternatively indirect contact can occur as the bacteria remains stable in the environment (soil, food, water, and bedding) for long periods of time- up to 6 months.
The bacteria enters the blood stream through minor breaks in the skin, exposed, abraded, softened skin or mucus membranes of the nose , lips and eyes. It causes fever, anemia (low red blood cell count), thrombocytopenia (low platelet count) and leukocytosis (high white blood cell count). Bleeding develops, dog turns jaundice (yellow tinge to the skin), electrolytes become depleted the renal (kidney) and liver values rise. The infection localizes and spreads to its primary target organ (the kidneys) and the second target organ (the liver) causing massive damage. The infection results in acute crisis and sets up potential chronic disease causes nephritis (inflammation of kidneys) and hepatitis (inflammation of the liver). The clinical signs range from acute renal failure to chronic disease to sudden death. Patients typically present dehydrated, urinating and drinking excessively, with a fever and gastrointestinal signs. In rare cases eyes and the central nervous system may be affected. The severity of disease is largely dependent on form (acute, subacute or chronic), the serovar (subtype), age and immunity of the patient.
In addition to the above findings any patient with acute kidney or liver failure should be screened for Leptospirosis. There are different types of blood tests to determine if Leptospirosis is the cause of the dog’s illness. Serology (identifies antibodies formed by the dogs immune system to fight the organism), PCR (identifies DNA form the organism in the bloodstream), MAT (microscopic agglutination – confirms exposure to the bacteria and IFA (fluorescence antibodies found the on urine). Radiographs may reveal renomegaly (swollen kidneys) or hemorrhage into the lungs.
Treatment is centered on supportive care. Huge amounts of IV fluids to combat dehydration and shock, to support the kidney’s and flush the toxins out of the system. In severe cases kidney dialysis maybe indicated. Blood transfusion may be needed in bleeding patients to treat for anemia and thrombocytopenia. Antibiotics are indicated to fight the bacteria itself. These patient should be isolated and handles with extreme caution given the zoonotic (transmission of the disease to people) potential. Good hygiene, wearing gloves and removing waste.
The prognosis ranges from guarded to good with ~ 70% survival rate Prognosis. With aggressive treatment most dogs will recover from the acute disease. However some patients never full recovery from this devastating infection and end up with permanent kidney damage. They will require a special low protein diet, kidney supplements, and frequent monitoring.
Preventing disease is centered on vaccines. However there are at least 8 different serovars with little to no overlap between vaccines. Many vaccine cover only 3-4 of the serovars and provide protection for ~ 6-8 months. Life style changes can be made to limit activity to marshy, muddy areas with low lying stagnant waters and control rodents.