(205) Swine fever is caused by one of the pesti family of viruses. The pig is the only natural host. The virus is spread from infected or carrier pigs via discharges from the nose, mouth and the urine and faeces and it is highly contagious.

Infection enters the pig by the mouth by direct contact of one pig with another. It gets into herds by the introduction of a carrier pig or infected meat. The virus survives in frozen carcasses for long periods of time

Clinical signs
When first introduced into the breeding herd it causes inappetence and high fevers. The virus can cross the placenta to invade the foetuses causing foetal death with mummification, abortions, malformations and increases in stillbirths.

An important characteristic is the birth of very weak pigs showing trembling like congenital tremor. In congenital tremor however there are no clinical signs of illness in the breeding females. Convulsions may occur with death within a few hours and sows may lose the use of their legs. The disease in the acute form will have dramatic effects on reproduction.

Diagnosis
CSF is a rapid spreading disease with high mortality. There are characteristic post-mortem changes with haemorrhagic lymph nodes, dead patches in the spleen, multiple small haemorrhages in the kidneys and so-called button ulcers in the gut.

These are all of diagnostic significance. Laboratory tests include the identification of viral antigen, isolation of the virus and the presence of antibodies in serum. In most countries CSF is notifiable.

Treatment

• There is no treatment.