|H3N2 canine influenza in Los Angeles County, 2017
- Please report cases of
Download our H3N2 Canine
Influenza handout -
In March 2017, canine influenza H3N2 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. Testing of two dogs revealed a strain of
canine influenza H3N2 commonly found in Asia.
After investigation, a total of 50 dogs
exposed to the virus were identified, including 35 sick
animals. H3N2 canine influenza was confirmed by laboratory
testing (PCR) in 6 dogs and the remainder of the sick dogs (29)
were suspected to also harbor the virus based on symptoms.
All exposed dogs (35 sick and 15 healthy) were put under isolation in 17 locations around LA County. Two
sick dogs died, however both were suffering
from other unrelated illnesses. As of May 31st, 2017 all
sick dogs have recovered and, the vast majority have been released from
isolation. Samples from several dogs were submitted to
veterinary virologists in order to compare this virus to the
canine influenza H3N2 virus that caused a large
outbreak in the Chicago area in 2015.
Canine influenza H3N2 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 at least 21 days afterward, even after they appear healthy. 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
canine influenza H3N2 .
The Veterinary Public Health Program (VPH) is
providing assistance during this outbreak by:
Enforcing quarantine of
all affected dogs to prevent spread of the
Alerting veterinarians in
LA County of the outbreak through the
Health Alert Network (AHAN).
veterinarians and affected parties by
On April 11, 2017 VPH was notified of an
unrelated case of a dog positive for H3N2 canine
influenza in early March, pre-dating the importation of the
sick dogs from Asia. This animal had been ill very early in
March when it was brought from San Bernardino County into LA
County. The dog was kept in isolation
for 2 weeks before being placed in a facility with a large
group of dogs.
Because dogs infected with canine
influenza H3N2 can sometimes be contagious for 3 weeks or
longer, VPH has been working closely with the
facility to check for further spread of the virus. Since
then, no additional cases have been found. VPH is currently
tracing dogs that left the facility in March and April in
order to further check for evidence of spread - so far most
have been healthy.
Impact of this
While the H3N2 strain of 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 canine influenza H3N2
appears to be contained 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 canine influenza
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, daycare) should be vaccinated against
canine influenza H3N2.
To prevent spread of
disease, do not let a sick pet share its
food bowl, leash, toys or other supplies
with other pets.
Wash your hands after
touching your pet.
Do not allow coughing dogs
into your lobby. Move them immediately into
an exam room, or (if it is not hot outside)
have the owner wait in the car with their
In any case with a
coughing dog, ask about the health of dogs
that spend time near the coughing dog, to
determine if there may be an outbreak.
Advise the owner to keep the coughing dog at
Report any suspected or
of influenza in dogs or cats to VPH using
this reporting form.
If a case is suspected,
use proper isolation measures to prevent
infection via direct contact or fomites.
disinfection and biosecurity available
Canine Influenza - Los Angeles County Department of Public
Canine influenza (Dog Flu) - Centers for Disease Control and
Canine Influenza - American Veterinary Medical Association
Canine Influenza H3N2 Updates - Cornell University Animal
Health Diagnostic Center
Last updated: June 1, 2017