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Veterinary Public Health


Veterinary Public Health

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Contact Information
Veterinary Public Health Program
313 N Figueroa St. Rm 1127
Los Angeles, CA 90012
Tel (213) 989-7060
Tel: (877) 747-2243
Fax (213) 481-2375
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Leptospirosis In Los Angeles County Dogs
  Graph of lepto cases in dog Los Angeles County 2005-2012
What is Leptospirosis? Leptospirosis is a disease caused by a  bacteria called Leptospira interrogans. It can infect humans, dogs, rats, mice, raccoons, skunks, opossums, cows, pigs, and many other animals. Infection with the bacteria occurs when the urine of an infected animal contacts the eyes, nose, mouth, or broken skin of another animal or person. Exposure to water or mud contaminated with urine may also be a source of infection.

Data on Local Cases of Leptospirosis in Animals.   Twenty-six cases of Leptospirosis cases have been reported by veterinarians in Los Angeles County dogs between 2005 and 2012, with nine  deaths.  Cases occurred in a wide range of locations around the county (see map, last updated in 2010).  The average age of these dogs was 6 years, with a range of 4 months to 12 years.  In 75% of cases, the dog had not been vaccinated against leptospirosis before illness.  In one fatal case, an older dog apparently became infected after a raccoon has washed its hands in the the dog's water bowl before the dog drank the water  In another fatal case, a dog became ill after its home became infested with rats.  It is unknown if the incidence of leptospirosis in local dogs is truly increasing because local veterinarians began reporting cases only recently.

What are the Symptoms? Symptoms in dogs may look like many other diseases, and often include fever, lethargy, low appetite, vomiting, and sometimes diarrhea. Yellowed mucus membranes and increased (or decreased) thirst and urination may be seen.

How do you know if your pet has leptospirosis?

The only way to know for sure is to have a veterinarian perform  special blood and urine tests to check for evidence of leptospirosis.


What is the treatment for a pet that has leptospirosis? Veterinarians treat infected pets by administering antibiotics that can kill the bacteria.  Most dogs with leptospirosis are seriously ill and are best treated in a veterinary hospital.


Human Health Risk.  In the United States, most human cases of leptospirosis occur after recreational exposure to contaminated lakes or streams, not from dogs.  However, the bacteria is in the urine of an infected dog. Therefore a person caring for a dog with leptospirosis should wear gloves, especially when cleaning up urine.


How can I prevent my dog from getting leptospirosis?

Wildlife Control. Do not attract wildlife to your yard.  Do not leave your pet's food and water outside at night.  If you have water outdoors for your pet during the day, change your pet's water daily in case it was contaminated by the urine of wild animals.  If you suspect a rat or mouse infestation in your house, consult an exterminator.

Consider leptospirosis vaccination. It is unknown if the local risk of leptospirosis infection is increasing. In many other parts of the United States leptospirosis infection risk is high.  However, it is clear that leptospirosis infection has occurred locally, even in dogs that do not leave their own yard.  Local data suggest that a variety of Leptospira serotypes (strains) of bacteria may have caused illness in dogs.  Therefore the 4-way vaccines (providing protecting against 4 strains of the bacteria) are a better choice for protection than the 2-way vaccines.

To report a case of Leptospirosis in a dog, download, complete, and fax in this form.

Scientific Articles
2004 - Reemerging Leptospirosis, California
2006 - Canine Leptospirosis 2002-2004


Updated 12/12/2013

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