H3N2 canine influenza virus causes severe clinical signs in dogs with induction of genes related to inflammation and apoptosis

We demonstrated canine influenza virus (H3N2) pathogenicity to dogs using microarray analysis. Many genes related to innate immunity, such as toll-like receptors, immune cells of natural killer cells, macrophages, neutrophils, nitric oxide and reactive oxygen species, and interferon, were induced. RNA was extracted from canine influenza virus H3N2-infected dogs. The lung RNA of uninfected dogs was used as a negative control. We compared gene expression levels between infected and uninfected dogs using microarray analysis.