Canine Influenza Virus (H3N8) is a novel canine virus first identified in September of 2004 as a respiratory disease in racing greyhounds in Florida. Although the virus has spread to 30 states and the District of Columbia, according to Dr. Crawford and Edward J. Dubovi, Ph.D., Professor of Virology, Cornell University College of Veterinary Medicine, two of the nation’s leading experts on Canine H3N8, actual infection remains rare for most dogs.
Dogs have no natural immunity to this specific influenza virus because it is a novel or new pathogen and, therefore, the infection can spread quickly through animal shelters, adoption groups, pet stores, boarding kennels, veterinary clinics and any area where dogs congregate. According to the U.S. Centers for Disease Control and Prevention (CDC), there is no evidence of transmission of this virus from dogs to people. The Canine Influenza Virus (CIV) is unique and is a different from the viral strain responsible for the bird (avian) or human flu virus. The virus apparently mutated from a horse strain of influenza. Influenza viruses are able to mutate or change in structure and more mutations will likely continue to occur. Five different mutations allowed this particular flu virus to spread from the horse to the dog.
Canine Influenza is fatal in approximately 5% of dog infected with the virus. Consequently, the total mortality rate is about 8%, which is four times above the mortality rate of the 1918 Spanish Flu pandemic in humans, a significant fact! The primary signs of this virus in dogs involve the respiratory tract and are a cough and a high fever. It usually takes a few weeks between initial infection of the virus and signs of coughing to appear. The risk is that this can develop into pneumonia and it also increases your dogs susceptibility to other respiratory disease causing agents including kennel cough. If your dog has similar symptoms visit your veterinarian. It is important to understand that there are many much less severe diseases that also present with similar signs.
Treatment for this virus are similar to those of most viral infections and consist of good supportive care, fluids to prevent dehydration and proper nutrition. Most dogs do recover with good nursing care from you and your veterinary team. On June 23, 2009, The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) announced that it has issued a one year conditional license to Intervet/Schering-Plough Animal Health for use of their canine influenza virus (CIV) vaccine in dogs through its Center for Veterinary Biologics (CVB). The vaccination’s potential value as a means of disease management is already being scrutinized by the veterinary community.
The Canine Influenza vaccination is composed of the killed (inactivated) virus H3N8. The vaccination does not prevent infection, therefore it does not prevent clinical signs of infection. The Canine Influenza vaccine will help to reduce the incidence and severity of lung lesions, as well as the duration of coughing and viral shedding. The vaccine is given as a shot, and is cautiously recommended for use in healthy dogs at six weeks of age or older to help control this disease. Under the conditional license, the canine flu vaccine may be distributed as authorized in each state, and used by, or under the supervision of, veterinarians. During the one-year conditional license period, the Center for Veterinary Biologics (CVB) will continue to monitor the product’s performance and will evaluate the company’s progress toward full licensure.
Typically this is a mild, self-limiting disease, but there are reports of severe illness and death in dogs due to this virus in animal shelters across the US. This virus is not thought to be contagious to people or other animals. This virus, like most are very species specific. There is no quick diagnostic test commercially available at this time. However, veterinarians can send blood samples to a diagnostic lab if they suspect this virus in any of their canine patients. Preventative measures to help your dog avoid this virus include avoiding unnecessary contact with other dogs especially if your dog is very old, very young or has a compromised immune system. Fortunately the vast majority of dogs are not at high risk of becoming ill.
The Center for Disease Control is monitoring this disease carefully. It is not necessary to keep your dogs inside for fear of contracting influenza. Normal precautions and the advice of your veterinarian will help you prevent any unnecessary exposure to Canine Influenza Virus.