Veterinary Public Health

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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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H3N2 canine influenza in Los Angeles County, 2017


VETERINARIANS - Please report cases of Canine Influenza herepdf icon 12432

Download our H3N2 Canine Influenza handout - Englishpdf icon 1243 Españolpdf icon 1243Esp


3 dogs


In March 2017, H3N2 canine influenza was identified in dogs in Los Angeles (LA) County. Most of the dogs were imported from Asia and seen by a veterinarian after arrival into LA County. The dogs showed signs consistent with influenza such as coughing, sneezing, fever and nasal discharge. A total of 27 dogs were sick with the disease and  treated with supportive care. Final testing of two dog revealed a strain of canine influenza (H3N2) commonly found in Asia, further testing is pending.


After investigation, a total of 35 sick dogs were identified out of 50 exposed, including  5  cases confirmed by laboratory testing (PCR) and 30 suspected. The sick dogs, plus an additional 8 healthy but exposed dogs, were put under quarantine or isolation in 16 locations around Los Angeles County. Two sick dogs have died, however both animals were suffering from other unrelated illnesses. As of April 21st, 2017 all remaining dogs have recovered and are being released from quarantine. Samples from several dogs have been submitted to veterinary virologists in order to compare this virus to the H3N2 canine influenza virus that caused a large outbreak in the Chicago area in 2015.


H3N2 canine influenza usually causes mild disease in dogs and on rare occasions can also infect cats. This strain of canine influenza was first found in the US in 2015 when it emerged in Chicago and spread to other parts of the country. Infected dogs start shedding the the virus 2 days before the start of clinical signs, and for 21 days or longer afterward. Transmission of influenza usually occurs through contact with infected respiratory secretions (e.g. coughing, sneezing) as well as from contamination of the environment (e.g. bedding, floors, bowls, collars, leashes).


To date, there is no evidence that humans can become sick with H3N2 canine influenza.


Response from the Department

VPH is providing assistance during this outbreak by:

  1. Enforcing quarantine of all affected dogs to prevent spread of the disease locally.

  2. Alerting veterinarians in LA County of the outbreak through the Animal Health Alert Network (AHAN).

  3. Supporting local veterinarians and affected parties by coordinating response.

Second cluster

During the investigation of the original influenza outbreak, the Veterinary Public Health Program (VPH) identified a dog that tested positive for H3N2 canine influenza in early March. This case originated in San Bernardino County and it pre-dates the importation of the sick dogs from Asia. VPH is working closely with the facility housing this dog to investigate any further spread of the virus. So far, no other animal that came in contact with this dog has tested positive for H3N2 canine influenza.


Impact of this virus

While the H3N2 strain canine influenza causes a mild disease, many dogs in Los Angeles County may be susceptible to this virus because of lack of previous immunity. As of now, the spread of H3N2 appears to be controlled in locally, however an uncontrolled outbreak may lead to thousand sick dogs. This can have a significant impact in dogs awaiting adoption in animal shelters. One of the most effective tools to reduce the number of  dogs sick with this disease is to vaccinate them against H3N2 canine influenza.



Pet owners

  • If you think your pet has influenza, keep it away from other animals and contact your veterinarian.

  • Pets that frequently interact with other dogs (e.g. dog park, groomer) should be vaccinated against H3N2 Canine influenza.

  • To prevent spread of disease, do not let a sick pet come in contact with other animals or share its food bowl, leash, toys or other supplies.

  • Wash your hands after touching your pet.


Veterinarians/Animal workers

  • Report any suspected case of influenza in dogs or cats to VPH using this reporting formpdf icon 12432.

  • If a case is suspected, use proper isolation measures to prevent infection via direct contact or fomites.

  • Recommendations for disinfection and biosecurity available here.


More Information

Canine Influenza - Los Angeles County Department of Public Health

Canine influenza (Dog Flu) - Centers for Disease Control and Prevention (CDC)

Canine Influenza - American Veterinary Medical Association (AVMA)

Canine Influenza H3N2 Updates - Cornell University Animal Health Diagnostic Center


Last updated: April 21, 2017

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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