During the highly pathogenic avian influenza (HPAI) H5N8 outbreak in South Korea, a dog reared in layer farm contaminated by the virus was reported seropositive for HPAI H5N8. In order to investigate the possibility of the adaptation and transmission of HPAI H5N8 to dogs, we inoculated the H5N8 to dogs in experimental condition. Weak viral genes in nasal swabs and seroconversions were detected even in contact dogs. Although the H5N8 virus doesn’t seem to adapt to canine species fully, these results suggest that surveillance on farm dogs should continue as a species in which avian influenza virus may acquire infectivity to mammals through frequent contact with the virus.