On March 31, 2017, Veterinary Public Health was alerted that the probable index case of a respiratory outbreak among imported dogs tested PCR positive for canine influenza H3N2. The dog was imported from China into Los Angeles County on March 11, 2017 and diagnosed with H3N2 canine influenza, but was not initially reported to Public Health.
There are approximately 35 dogs involved in the outbreak, most of which have been ill. Further diagnostic tests are pending. All dogs associated with the outbreak are spread over nine locations in LA County and have all been placed under quarantine. Veterinary Public Health is working closely with local partners to trace back all of the dogs’ potential contacts. To date, there is no evidence of further spread of canine influenza H3N2 within the LA County beyond the initial cluster.
Canine influenza H3N2 is a contagious virus that causes a respiratory infection in dogs and occasionally in cats. It was first reported in South Korea in 2007 and has been circulating in Asia. It was first detected in the United States during a large canine influenza outbreak in the Chicago area starting in early 2015, during which over a thousand dogs were reported ill in the Chicago/Midwest area before the infectious cause was discovered. It has not been known to cause illness in people. A vaccine is available to protect dogs against it.
The first and only other case of canine influenza H3N2 in a dog in LA County was a single case reported in 2015. There have been no confirmed reports received of LA County dogs being infected with the older canine influenza strain – H3N8 – in Los Angeles County since 2011.
With the increase in imported dogs from Asia, the evidence of spread, and the time it will take to trace all the dogs’ potential contacts, Veterinary Public Health recommends that dogs that dogs that interact with other dogs should be vaccinated against canine influenza, especially against H3N2.
Dogs are most contagious during the incubation period (2-4 days post exposure) when they are not exhibiting clinical signs. Dogs that are infected with canine influenza H3N2 are contagious for up to 3 weeks, therefore dogs infected with H3N2 should be isolated for at least 21 days.
The keys to preventing the spread of canine influenza H3N2 virus include:
• Frequent cleaning and disinfection in pet boarding facilities, grooming salons, and veterinary practices, with written protocols and policies for maintaining infection control
• Frequent hand washing by animal owners and handlers – wash hands after handing each animal.
• Not sharing equipment or toys between healthy and sick animals.
• Washing and disinfecting medical or grooming equipment after use on animals
• Handling sick animals last in group settings
• Testing any sick animals
Karen Ehnert, DVM, MPVM, DACVPM
Director Veterinary Public Health
Los Angeles County Department of Public Health
313 N. Figueroa St, Room 1127
Los Angeles, CA 90012
(213) 481-2375 Fax