INFECTION STUDIES WITH CANINE-DISTEMPER VIRUS IN HARBOR SEALS

Infection studies in harbour seal (Phoca vitulina) were conducted with the Snyder-Hill strain of canine distemper virus (CDV) that is virule nt for dog and mink. The inoculated seals showed clinical symptoms whi ch were to some degree similar to those observed in CDV infections of sensitive species of carnivores. Viral replication in lymphoid cells w as followed by an extended period of immunosuppression. The results di d not provide conclusive evidence for viral replication in surface epi thelia of seals, and accordingly no spread of the infection to contact seals and mink was demonstrated. The pathogenicity of the infection d id not increase upon a second viral passage in seal. The serological d ata showed that CDV-infected seals mounted an early virus specific ant ibody response. Overall, the results indicated that the harbour seal w as not especially sensitive to CDV infection. The differences in the i n vivo biological properties of CDV and PDV add to the distinction bet ween these viruses at the genomic and antigenic levels.