Canine Influenza Virus, type A H3N8 – an emerging canine respiratory disease threat
A new respiratory viral disease, Canine Influenza virus (CIV), aka “Dog Flu” was discovered here in the USA as the cause of respiratory disease outbreaks in thousands of greyhound dogs at 20 different race tracks in eight states from 2003 to 2005. At that time it spread too many different facilities that had dogs such as animal shelters, kennels and veterinary hospitals. Recently, the virus has been identified again in outbreaks of respiratory illness in various locations.
Prevalence: Laboratory testing and surveillance has now identified thousands of dogs in 30 states and the District of Columbia that had confirmed CIV infections. The virus is now established in communities in the states of Colorado, Florida, Pennsylvania, New Jersey and New York.
Source of infection: CIV originated from the interspecies transmission of the equine influenza, A H3N6 virus from horses to dogs sometime prior to 2004.
All dogs are at risk: Since this is a new infectious agent for dogs there is no natural immunity. An individual dog’s risk is dependent on its lifestyle and exposure to other dogs i.e. the highest risk for contracting CIV is for dogs housed in kennels, pet shops, shelters and rescue groups; going to day care, dog parks, dog shows/ competition trials, veterinary hospitals, and grooming establishments.
Dogs of any age breed or health status are susceptible. CIV does not infect people.
Transmission is either by oro-nasal (mouth-nose) contact with infected dogs, contaminated surfaces or by inhalation of aerosols produced by coughing and sneezing. Because it is highly contagious, virtually all exposed dogs become infected. Within 2 to 4 days of exposure approximately 80% will shed the virus and suffer varying degrees of illness; fever, coughing (for up to 3 weeks), sneezing and eye or nasal discharge.
The other 20% will have a subclinical infection with no signs of illness but still readily shed the virus and can infect other dogs.
Most sick dogs recover without complications but approximately 1 in 5 can develop a severe infection with pneumonia that can be life threatening and require hospitalization and intensive care to survive.
Currently there has not been a confirmed CIV outbreak in Maryland, but there was a confirmed outbreak at a shelter in northern Virginia. The situation could quickly change, however, due to our mobile population accompanied by their canine companions.
The good news is that a CIV vaccine has been approved by the USDA and is now available to vaccinate dogs. It is reported that the vaccine does not prevent the disease but does significantly reduce the severity of the pneumonia and shorten the duration of coughing and viral shedding. The vaccine is administered to dogs, 6 weeks and older in two doses given two to four weeks apart and then annually for those dogs considered at risk of exposure. One dose does not generate sufficient immunity to protect the dog, experts say. It appears that it takes the two doses to provide protection.
The vaccine has been reported to be very safe with no side effects. We are currently vaccinating all hospital staff dogs to further evaluate for side effects. Due to the potential for serious illness and the contagious nature of CIV to a highly susceptible canine population, we encourage you to vaccinate your dog(s) for CIV if their lifestyle puts them at risk of exposure. Examples of this would be: if you travel with your pet to areas where it has been found, if your dog has been at a kennel that had an outbreak of a respiratory disease, or if an outbreak of canine influenza is reported in Florida.
We will continue to monitor for any verifiable news of a CIV outbreak in Florida and report to you on the website and possibly by other means. Should such an event occur, we will likely require that all boarding, day care dogs and hospitalized dogs to be vaccinated for CIV.
Please call if you have questions or to schedule an appointment for the vaccine series.
For additional information on Canine influenza virus, see the following links:
www.doginfluenza.com
www.avma.org/public_health/influenza/canine_bgnd.asp