The canine influenza virus (CIV) is a newly appearing virus in dogs, and it is now considered a part of the respiratory disease complex that includes parainfluenza virus and Bordetella bacteria. Kennels, groomers and veterinary hospitals have required protection against these two pathogens for a long time.
CIV is a highly contagious virus that will infect virtually every dog that is exposed to it. About 80 percent of dogs infected will show clinical signs, which include fever, malaise and prolonged cough. Of those showing clinical signs, some patients will develop a severe form of the disease, which often involves a secondary pneumonia manifested by a thick, yellow-green nasal discharge and high fever.
These cases frequently require extended and expensive hospitalization stays in strict isolation with intravenous fluid, antibiotic and respiratory therapy. In spite of the best treatment regimens, it is estimated based on experience that 3 to 8 percent of these patients may die of the disease and its complications.
The vaccine has been shown to have virtually no side effects and is highly effective in either preventing infection or lessening the clinical signs and duration of infection and virus shedding. Dogs over six weeks of age are protected by getting two injections of vaccine, given two to four weeks apart. (My boldface - Susan)
— John G. DeVries