Distemper viruses in seals - literature review.

Phocine distemper virus (PDV) has caused two severe disease outbreaks in harbour seals (Phoca vitulina) in Europe in 1988 and 2002. Canine distemper virus can also infect seals and it has caused mass deaths of Caspian (Phoca caspica) and Baikal seals (Phoca sibirica). According to the descriptive epidemiological articles, the behaviour of the seals as well as the season of the infection seem to have an important role in the mortality and spreading of the disease. Large distemper virus outbreaks have never been detected in seals in the main pool of the Baltic Sea. The growth of the seal population and global warming may, however, favour contact between individual seals and seal species. This can make the risk of the outbreak more important in the Baltic Sea. Saimaa ringed seals (Phoca hispida saimensis) are probably well protected against phocine distemper virus because of their geographical isolation. Canine distemper virus is, however, a potential risk in a lake environment.