Isolation of a parapoxvirus from a grey seal (Halichoerus grypus)

A grey seal (Halichoerus grypus) developed cutaneous pocks which progressed to involve the skin extensively, necessitating euthanasia. Macroscopically and histologically the lesions resembled previous descriptions of parapoxvirus infections of seals and virus particles were observed in preparations of a scab and a skin lesion. Suspensions of the scab and skin lesion were prepared and inoculated on to monolayer cultures of grey seal kidney cells. After 25 days in culture and three passages, cytopathic effects were observed and parapoxvirus particles were detected by electron microscopy in the supernatant fluid. Both isolates were adapted to cultures of fetal lamb muscle cells and shown to be antigenically related to orf virus.