ThePigSite Quick Disease Guide
Swine Fevers; African, Classical, Hog Cholera
The pig is the only natural host. The virus is spread from infected or carrier pigs via discharges from the nose, mouth, urine and faeces or infected semen and it is highly contagious. The virus survives in frozen carcasses for long periods of time
Control is by slaughter or as a last resort by vaccination. African swine fever (ASF) and Classical Swine fever are caused by very similar viruses which are only distinguishable by laboratory testing.
- High fever.
- Death sudden.
- Piglet malformations.
- Very weak piglets at birth showing trembling (congenital tremor).
- When first introduced into the breeding herd it causes inappetence and high fevers.
- The virus can cross the placenta to invade the foetuses.
- Returns 18 23 days.
- Foetal death with mummification.
- Embryo death.
- Dog sitting position.
- Nervous signs
- Increases in stillbirths.
- Convulsions may occur with death within a few hours.
- Sows may lose the use of their legs.
- The disease in the acute form will have dramatic effects on reproduction through abortions and embryo and foetal deaths.
- Pigs dejected - hang their heads.
- Not eating.
- Pigs chilled - huddled together.
- Eye discharge - heavy.
- High persistent fever.
- Nervous signs - Incoordination, swaying on the legs.
- Blue discoloration of the skin.
- High mortality.
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.
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.