Susceptibility of dogs to West Nile virus: a survey and pathogenicity trial.

A serological survey of dogs from the highveld region of South Africa showed that 37 per cent (138 of 377) had neutralizing antibodies to West Nile (WN) virus and only 2.7 per cent (10 of 377) had antibodies to Sindbis virus. WN virus was isolated from one of the WN-antibody negative sera. Because these results suggested that dogs may play an important part in the epidemiology of WN virus, a pathogenicity trial was carried out. Two of three dogs infected with WN virus had a mild recurrent myopathy, but no other abnormalities were detected in the biochemical or haematological tests performed on any of the dogs. All three dogs developed antibodies but a low titre-viraemia was detected in only one dog. It was concluded that dogs do not play an important part in the epidemiology of WN virus but they may play a small part in the maintenance of the virus.