In the News
Canine
Influenza
Control of Canine
Influenza in Dogs
Questions, Answers, and Interim Guidelines
updated December 1, 2005
The following document has been developed via consultation among
the American Veterinary Medical Association, the University
of Florida, Cornell University, and the U.S. Centers for Disease
Control and Prevention, and is advisory in nature. It is intended
to answer common questions and to provide guidance on managing
affected dogs and for persons working with or handling affected
dogs. This document reflects what is known as of October 17,
2005, and may be updated as more information becomes available.
What is canine influenza?
Canine influenza is a highly contagious respiratory infection
of dogs that is caused by a virus. The canine influenza virus
is closely related to the virus that causes equine influenza
and it is thought that the equine influenza virus mutated to
produce the canine influenza virus.
Two clinical syndromes have been seen in dogs infected with
the canine influenza virus—a mild form of the disease
and a more severe form that is accompanied by pneumonia.
• About the mild form—Dogs suffering with the mild
form of canine influenza develop a soft, moist cough that persists
for 10 to 30 days. Some dogs have a dry cough similar to the
"kennel cough" caused by Bordetella bronchiseptica/parainfluenza
virus complex. For this reason, canine influenza virus infections
are frequently mistaken for "kennel cough." Dogs with
the mild form of influenza may also have a thick nasal discharge,
which is usually caused by a secondary bacterial infection.
• About the severe form—Dogs with the severe form
of canine influenza develop high fevers (104ºF to 106ºF)
and have clinical signs of pneumonia, such as increased respiratory
rates and effort. Pneumonia may be due to a secondary bacterial
infection.
Because this is a newly emerging disease, almost all dogs, regardless
of breed or age, are susceptible to infection and have no immunity.
Virtually all dogs that are exposed to the virus become infected
and nearly 80% show clinical signs of disease. Fortunately,
most affected dogs have the mild form.
Do dogs die from canine influenza?
Fatal cases of pneumonia resulting from infection with canine
influenza virus have been reported in dogs, but the fatality
rate (5% to 8%) has been low so far.
How widespread is the disease?
The first recognized outbreak of canine influenza in the world
is believed to have occurred in racing greyhounds in January
2004 at a track in Florida. From June to August of 2004, outbreaks
of respiratory disease were reported at 14 tracks in 6 states
(Alabama, Arkansas, Florida, Kansas, Texas, and West Virginia).
Between January and May of 2005, outbreaks occurred at 20 tracks
in 11 states (Arizona, Arkansas, Colorado, Florida, Iowa, Kansas,
Massachusetts, Rhode Island, Texas, West Virginia, and Wisconsin).
Infection has also been confirmed in pet dogs in California,
Connecticut, Florida, Georgia, Massachusetts, North Carolina,
New Jersey, New York, Ohio, Oregon, Pennsylvania, Washington
State, and Washington, DC. These cases occurred in animal shelters,
humane societies, rescue groups, pet stores, boarding kennels,
and veterinary clinics.
How is a dog with canine influenza treated?
As with any disease caused by a virus, treatment is largely
supportive. Good animal care practices and nutrition assist
dogs in mounting an effective immune response. In the milder
form of the disease, a thick green nasal discharge, which most
likely represents a secondary bacterial infection, usually resolves
quickly after treatment with a broad-spectrum bactericidal antimicrobial.
In the more severe form of the disease, pneumonia is thought
to often be caused by bacterial superinfection, and responds
best to hydration (sometimes via intravenous administration
of fluids) and a broad-spectrum bactericidal antimicrobial.
Is canine influenza virus transmissible from dogs to
humans?
To date, there is no evidence of transmission of canine influenza
virus from dogs to people.
Do I need to be concerned about putting my dog in day
care or boarding it at a kennel?
Dog owners should be aware that any situation that brings dogs
together increases the risk of spread of communicable illnesses.
Good infection control practices can reduce that risk, so dog
owners involved in shows, sports, or other activities with their
dogs or who board their dogs at kennels should ask whether respiratory
disease has been a problem there, and whether the facility has
a plan for isolating dogs that develop respiratory disease and
for notifying owners if their dogs have been exposed to dogs
with respiratory disease.
As long as good infection control practices are in place, pet
owners should not be overly concerned about putting dogs in
training facilities, dog parks, kennels, or other areas frequented
by dogs.
My dog has a cough...what should I do?
Schedule an appointment with your veterinarian so that he or
she can examine and evaluate your dog and recommend an appropriate
course of treatment. If canine influenza is suspected, treatment
will usually focus on maximizing the ability of your dog's immune
system to combat the virus. A typical approach might include
administration of fluids if your dog is becoming dehydrated
and prescribing an antimicrobial if a secondary bacterial infection
is suspected.
Canine influenza virus can be spread via direct contact with
respiratory secretions from infected dogs, and by contact with
contaminated inanimate objects. Therefore, dog owners whose
dogs are coughing or exhibiting other signs of respiratory disease
should not participate in activities or bring their dogs to
facilities where other dogs can be exposed to them. Clothing,
equipment, surfaces, and hands should be cleaned and disinfected
after exposure to dogs showing signs of respiratory disease
to prevent transmission of infection to susceptible dogs. Clothing
can be adequately cleaned by using a detergent at normal laundry
temperatures.
I manage a kennel/veterinary clinic/animal shelter/dog
day care center. How do I keep canine influenza out of my facility,
and if it does enter my facility, what should I do?
Viral disease is usually best prevented through vaccination.
Unfortunately, at this time no vaccine is available to protect
dogs against canine influenza. Vaccination against other pathogens
causing respiratory disease, however, may help prevent more
common respiratory pathogens from becoming secondary infections
in a respiratory tract already compromised by influenza infection.
In addition, knowing that dogs are vaccinated against these
pathogens may help facility managers distinguish canine influenza
from other respiratory diseases. For these reasons, a veterinarian
should determine which vaccinations are needed based on related
risks and benefits and should administer these at least 2 weeks
prior to planned visits to dog activity and care facilities
(e.g., kennels, veterinary clinics, dog day care centers, training
facilities, dog parks). Dogs admitted to shelters should be
vaccinated on admission.
Routine infection control precautions are key to preventing
spread of viral disease within facilities. The canine influenza
virus appears to be easily killed by disinfectants (e.g., quaternary
ammonium compounds and bleach solutions at a 1 to 30 dilution)
in common use in veterinary clinics, boarding facilities, and
animal shelters. Protocols should be established for thoroughly
cleaning and disinfecting cages, bowls, and other surfaces between
uses. Employees should wash their hands with soap and water
(or use an alcohol-based hand cleaner if soap and water are
unavailable) before and after handling each dog; after coming
into contact with a dog's saliva, urine, feces, or blood; after
cleaning cages; and upon arriving at and before leaving the
facility (see "I
work in a kennel/animal care facility. What should I do to prevent
transmission of influenza virus from infected dogs to susceptible
dogs?").
Animal care facility staff should be alerted to the possibility
that a dog with a respiratory infection could be presented for
care or boarding. If a dog with respiratory signs is presented,
staff members should inquire whether the dog has recently been
boarded or adopted from a shelter, has recently participated
in dog-related group activities, or whether it has been exposed
to other dogs known to have canine influenza or kennel cough.
The dog should be brought directly into a separate examination/triage
area that is reserved for dogs with respiratory signs and should
not be allowed to enter the waiting room or other areas where
susceptible dogs may be present.
Dogs with suspected canine influenza virus infection that is
discovered after entry into the facility should be evaluated
and treated by a veterinarian. Isolation protocols should be
rigorously applied for dogs showing signs of respiratory disease,
including the wearing of disposable gloves by persons handling
infected dogs or cleaning contaminated cages. Respiratory disease
beyond what is considered typical for a particular facility
should be investigated, and the investigation should include
submission of appropriate diagnostic samples (see "What
diagnostic tests will tell me whether a dog has canine influenza?").
What diagnostic tests will tell me whether a dog has
canine influenza? What samples do I send? Where do I send the
samples? How do I distinguish between canine influenza and kennel
cough?
There is no rapid test for diagnosis of acute canine influenza
virus infection. Diagnosis may be confirmed through serologic
testing. Antibodies to canine influenza virus may be detected
as early as seven days after onset of clinical signs. Convalescent-phase
samples should be collected at least two weeks after collection
of the acute-phase sample. If an acute-phase sample is not available,
testing a convalescent-phase sample can reveal whether a dog
has been infected at some point in the past.
Other diagnostic options applicable to dogs that have died from
pneumonia are viral culture and polymerase chain reaction (PCR)
analysis, using fresh (not formalin-preserved or frozen) lung
and tracheal tissues. Virus detection in respiratory secretion
specimens from acutely ill animals using these methods is possible
but generally unrewarding. The Cornell Animal Health Diagnostic
Center is currently accepting samples for analysis. For detailed
information on sample submission, visit www.diaglab.vet.cornell.edu/issues/civ.asp.
I work in a kennel/animal care facility. What should
I do to prevent transmission of influenza virus from infected
dogs to susceptible dogs?
Canine influenza is not known to be transmissible from dogs
to people. However, caretakers can inadvertently transmit canine
influenza virus from infected dogs to susceptible dogs by not
following good hygiene and infection control practices. To prevent
spread of canine influenza virus, caretakers should take the
following precautions:
• Wash hands with soap and water (if soap and water are
unavailable, use an alcohol-based hand cleaner)
o Before and after handling each animal
o After coming into contact with animal saliva, urine, feces
or blood
o After cleaning cages
o Before eating meals, taking breaks, smoking or leaving the
facility
o Before and after using the restroom
• Wear a barrier gown over your clothes and wear gloves
when handling sick animals or cleaning cages. Discard gown
and gloves before working with other animals
• Consider use of goggles or face protection if splashes
from contaminated surfaces may occur
• Bring a change of clothes to wear home at the end
of the day
• Thoroughly clean clothes worn at the animal facility
• Do not allow animals to "kiss" you or lick
your face
• Do not eat in the animal care area
• Separate newly arriving animals from animals that
have been housed one week or longer.
• Routinely monitor animals for signs of illness. Separate
sick animals from healthy animals, especially animals with
signs of respiratory disease.
• There is no evidence of transmission of canine influenza
virus from dogs to people. However, because of concerns about
diseases that are transmissible from dogs to people, in general,
it may be prudent for young children, the elderly, pregnant
women, and immunocompromised persons to limit or avoid contact
with animals that are ill.
Is canine influenza transmissible to from dogs to
horses or other animal species?
At this time, there is no evidence of transmission of canine
influenza from dogs to horses, cats, ferrets, or other animal
species. However, the infection control measures outlined
in the section titled "I work in a kennel/animal care
facility. What should I do to prevent transmission of influenza
virus from infected dogs to susceptible dogs?" are recommended
to prevent spread of the virus.
For additional information and updates, please visit these
websites:
American Veterinary Medical Association - www.avma.org
University of Florida College of Veterinary Medicine - www.vetmed.ufl.edu/pr
Cornell University Veterinary Diagnostic Laboratory - http://www.diaglab.vet.cornell.edu/issues/civ.asp
Centers for Disease Control and Prevention - www.cdc.gov/healthypets
Association of Shelter Veterinarians - www.sheltervet.org
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