What is Canine Influenza Virus (CIV)?
Canine Influenza Virus is a highly contagious respiratory disease in dogs caused by a specific Type A H3N8 influenza virus.
This is a disease of dogs, not of humans and cannot be transferred to humans from dogs or visa versa. The H3N8 virus was first discovered over 40 years ago in horses. In 2004, however, cases of an unknown respiratory illness in Greyhound dogs were reported. Further investigation showed that this respiratory illness was caused by the equine influenza A H3N8 virus. Scientists now believe that this virus jumped species (from horses to dogs) and can now spread efficiently from dog to dog.
What is the Canine Infectious Respiratory Disease CIRS) Complex?
The CIRD complex (historically referred to as kennel cough) is a group of different viral and bacterial diseases that are contagious to dogs and all cause similar clinical signs such as coughing, sneezing, fever, nasal discharge, and ocular (eye) discharge. Canine Influenza Virus is just one cause of respiratory illness in dogs and cannot easily be distinguished from other pathogens involved in the canine infectious respiratory disease (CIRD) complex, including:
Bordetella brochiseptica
Canine Herpes virus
Parainfluenza Virus
Adenovirus type 2
Canine Distemper Virus
Mycoplasma spp.
Canine Respiratory Coronavirus
Why is Canine Influenza Virus (CIV) so concerning?
Because CIV is a relatively new cause of disease in dogs, most dogs are naïve, meaning that they have no natural immunity, and thus, almost all dogs exposed will become infected. What makes this disease even harder to control is that clinical signs such as coughing and runny nose often don’t appear until 4-5 days after exposure, however, active shedding of the virus through nasal secretions occurs 2-4 days after exposure. This means that dogs will be at their most infectious (spreading disease to other dogs) prior to showing clinical signs of disease! This disease is easily transmitted within 25 feet by direct contact, coughing, sneezing, or contamination of objects and surfaces.
Are there any distinctive signs for CIV?
Of the dogs that become infected, about 80% will have the mild form of disease, showing signs similar to kennel cough (coughing, sneezing, runny nose). Most dogs with this form of disease will recover on their own, often with little need for medical intervention. The other 20% of infected dogs may progress to a more severe form of disease characterized by a high fever, pronounced nasal discharge, and pneumonia. These dogs are more likely to feel sick, showing signs of lethargy and inappetance. Supportive care (IV fluids, oxygen therapy, and antibiotics) is commonly required to treat these patients. Anywhere from 5-8% of the dogs infected with CIV will die from the disease.
What should owners do with coughing dogs?
Owners should have their dog seen by a veterinarian if they are coughing or showing any other signs of respiratory illness. It is also important to separate any coughing dog from other dogs to decrease their risk of exposure. Because CIV is not very stable in the environment, it can easily be killed by cleaning all contaminated surfaces with alcohol or dilute bleach (1:30 ratio of bleach:water).
Is there a vaccination for Canine Influenza Virus?
In response to the growing incidence of outbreaks of CIV (mostly in shelters and kennels), Intervet/Schering-Plough Animal Health has developed a Canine Influenza Vaccine. Similar to the Kennel Cough (Bordetella) vaccine, the Canine Influenza vaccine will not prevent infection, but decrease the clinical signs and severity of disease. The vaccine will reduce the duration and severity of coughing, protect against the formation and severity of lung lesions (pneumonia), and significantly reduce the duration and degree of viral shedding.