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Family Pet Animal Care - leptospirosis vaccinations


Family Pet Animal Care

Leptospirosis Vaccinations - October 2015 

by Dr. Michael Trapani

Would you like to update your dog’s leptospirosis vaccinations today, Mrs. Rosencrantz?” 

To vaccinate or not to vaccinate? That is the question. Whether ‘tis nobler in the mind to suffer the slings and arrows of outrageous fortune or to take arms against a sea of troubles, and by opposing, end them. 

Yup, that’s what Shakespeare was talking about. Right on cue, Mrs. Rosencrantz answers, “What’s leptospirosis?”

How much time do you have? Leptospirosis is a bacterial disease that affects dogs, and also cattle, rodents, small mammals like deer, rabbits, hedgehogs, sheep, raccoons, opossums, skunks, and people. Even some marine mammals can become infected and spread the disease. Worldwide, it is estimated that seven to ten million people are infected by leptospirosis annually. About a million of those cases are severe and about 59,000 people will die. And yes, people can become infected by handling infected dogs. 

Leptospirosis is caused by corkscrew-shaped bacteria that are typically ingested in urine-contaminated water or soil. Soils most likely to support infective leptospira include drainage ditches, culverts, muddy waterways, and urine-contaminated livestock housing areas, particularly those accessible to wild animals. Dogs may ingest the urine of an infected animal during predation, or drink from an infected puddle. House dogs have contracted leptospirosis, apparently from licking the urine of infected mice inside the home.

In humans, the disease has a number of colorful names including field fever and rat catcher’s yellows. When leptospirosis causes jaundice, kidney failure, and bleeding, it is called Weil’s Disease, after the doctor who first described the condition in 1886.

Leptospirosis is difficult to recognize in dogs. The disease incubates for 4 to 12 days after exposure, then starts with a fever and loss of appetite, vomiting, lethargy, malaise, discomfort, increased water intake with increased urination, and less commonly, bloody urine or diarrhea. Even though the disease attacks primarily the kidneys and liver, it has the appearance of a gastro-intestinal problem. In some cases, hepatitis causes the whites of the dog’s eyes to turn yellow (jaundice), sometimes with bleeding from the mouth and bloody stools. Death usually occurs as a result of kidney failure. 

My typical leptospirosis patient was “just fine yesterday.” Today, he’s feverish, uncomfortable, and not eating. By tomorrow, his kidneys will show measurable loss of function. This is Acute Kidney Injury (AKI) and accounts for about 90% of recognized leptospirosis cases. It may take a week or more of treatment to find out whether we’ve treated him aggressively enough to allow his kidney function to regenerate. Leptospirosis patients should be hospitalized to prevent exposure of people in the household.

Diagnosis of leptospirosis is difficult. The bacteria can sometimes be seen in urine using highly specialized microscope techniques, but often their numbers are too small for reliable identification. Antibody tests are available: two samples are collected ten days apart and a measured increase in antibody levels may confirm the presence of the disease. New ELISA and PCR technologies promise to make diagnosis faster and more reliable, but time delays and the necessity of repeat testing still makes diagnosis of leptospirosis a difficult and expensive proposition. Most cases are diagnosed “clinically” based upon the attending veterinarian’s impression, the patterns observed in non-specific blood and urine tests, and the patient’s response to treatment.

Treatment of leptospirosis requires immediate and intensive antibiotic treatment to stop the progression of the infection while fluid therapy is administered to support liver and kidney function until the victim is able to regain its ability to support itself. Of course, hospital isolation is important to protect spread of the disease to adults and children in the household.

Leptospirosis is a sporadic, but not uncommon disease in Sonoma County. In recent years, we seem to be seeing the disease more often. I suspect this is yet another effect of the drought: as wild animals are forced to move closer to human habitations while seeking water, they increase our dogs’ exposure.

Leptospirosis is a complicated illness and your decision of whether a particular dog has risk sufficient to warrant vaccination against this deadly disease is a difficult one. Some dogs have no significant risk factors and do not benefit from vaccination. Other dogs, particularly those living in rural areas or having exposure to potentially infectious water sources or wild mammal habitat may easily “suffer the slings and arrows of outrageous fortune.” For these animals, leptospirosis vaccination allows your dog “to take arms against a sea of troubles.”

Vaccination is a cheap, safe and effective way to immunize your dog against leptospirosis. Ask your veterinarian about protecting your pet.