Veterinary Public Health

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Veterinary Public Health Program
313 N Figueroa St. Rm 1127
Los Angeles, CA 90012
Tel (213) 288-7060
Fax (213) 481-2375
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Leptospirosis in Dogs

What is leptospirosis (lepto)?
Lepto is a disease caused by a bacteria called Leptospira interrogans. It can infect multiple species of mammals, including humans, dogs, rats, mice, raccoons, skunks, opossums, cows, and pigs. Leptospirosis is occasionally diagnosed in dogs in LA County.

What are the symptoms of lepto?

In dogs: Symptoms are variable and may include fever, lethargy, low appetite, vomiting, diarrhea, yellowed mucus membranes and increased (or decreased) thirst and urination.


In humans: Symptoms are variable and may include fever, severe headache, and muscle aches. In severe cases, people may have yellowed mucus membranes, cause kidney damage and respiratory distress. Click here to learn more about lepto in people. 

How is lepto transmitted?
Infection occurs when the urine of an infected animal contacts the eyes, nose, mouth, or broken skin of another animal or a  person. Exposure to water or mud contaminated with urine may also spread it. In the United States, most human cases of lepto occur after recreational exposure to contaminated lakes or streams, not from dogs. The bacteria is shed in the urine of an infected dog. Therefore a person caring for a dog with lepto should wear gloves, especially when cleaning up urine.

What is the treatment for lepto in dogs?
Veterinarians treat infected pets by administering specific antibiotics that can kill the bacteria. Most dogs with lepto are seriously ill, should be treated in a veterinary hospital.

How can I protect my dog from lepto?

1. 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.  


2. Consider vaccinating your dog for lepto. Local data suggest that a variety of Leptospira serotypes (strains) of bacteria may have caused illness in dogs. Therefore the 4-way vaccines (protecting against 4 strains of the bacteria) are a better choice for protection than the 2-way vaccines.

Reporting Lepto Cases
VETERINARIANS: Report a case of heartworm disease by using this form or by using the online reporting portal.



Lepto in dogs in LA County

  • 29 cases reported
  • Case categorization based on LA County's
    leptospirosis case definition for dogs
    • 79% confirmed
    • 14% probable
    • 7%  suspected
  • In 2014,  veterinary diagnostic laboratories began reporting cases
  • Modes of exposure
    • Most cases exposed to wildlife, or water contaminated by wildlife, in or near the dog's home environment (such as  backyard water bowls. fountains, and ponds)
  • Locations of cases
    • Areas throughout LA County, no clear geographic pattern

    • Due to the cost of testing, may be more likely to be diagnosed in dogs in higher income areas

2015-2015 graph of lepto cases in dogs los angeles county2005-2015 map of lepto cases in dogs los angeles county


Last updated: July 27, 201
Public Health has made reasonable efforts to provide accurate translation. However, no computerized translation is perfect and is not intended to replace traditional translation methods. If questions arise concerning the accuracy of the information, please refer to the English edition of the website, which is the official version.
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