Classical swine fever (CSF) or hog cholera (also sometimes called pig plague based on the German word Schweinepest) is a highly contagious disease of swine (Old World and New World pigs). It has been mentioned as a potential bioweapon.
Swine fever causes fever, skin lesions, convulsions, splenic infarctions and usually (particularly in young animals) death within 15 days.
The disease has acute and chronic forms, and can range from severe, with high mortality, to mild or even unapparent.
In the acute form of the disease, in all age groups, there is fever, huddling of sick animals, loss of appetite, dullness, weakness, conjunctivitis, constipation followed by diarrhoea, and an unsteady gait. Several days after the onset of clinical signs, the ears, abdomen and inner thighs may show a purple discoloration. Animals with acute disease die within 1–2 weeks. Severe cases of the disease appear very similar to African swine fever. With low-virulence strains, the only expression may be poor reproductive performance and the birth of piglets with neurologic defects such as congenital tremor.
A small fraction of the infected pigs may survive and are rendered immune. Artificial immunization procedures were first developed by Marion Dorset.
The disease is endemic in much of Asia, [Central and South America, and parts of Europe and Africa. It was believed to have been eradicated in the United Kingdom by 1966 (according to the Department for Environment, Food and Rural Affairs), but an outbreak occurred in East Anglia in 2000. On January 31, 1978 USDA Secretary Bob Bergland declared that the United States was free of the disease. The appearance of CSF in Italy and Spain was traced by in a retroactive genetic analysis. Greiser-Wilke et al., 2000 traced these to shipments of piglets from the Netherlands.
Other regions believed free of CSF include Australia, Belgium (1998), Canada (1962), Ireland, New Zealand, and Scandinavia.
The infectious agent responsible is a virus CSFV (previously called hog cholera virus) of the genus Pestivirus in the family Flaviviridae.