Classical swine fever
Also called Hog cholera
A serious viral disease of pigs with high fever, loss of appetite, skin redness and sudden deaths. Milder forms are now common and are easy to miss.
Cause and spread
- Cause
- Classical swine fever virus (CSFV), a pestivirus.
- How it spreads
- By breathing or eating the virus from infected pigs, their body fluids, or contaminated feed, vehicles and people. Pigs can shed it before they show signs, and it survives in meat and blood after death. Incubation is usually 3 to 7 days.
Signs to watch for
- High fever, huddling, weakness and loss of appetite
- Redness or purple skin patches, especially on the ears and belly
- Eye crusting and discharge
- Constipation followed by diarrhoea
- Abortion, stillbirth and weak piglets
- Sudden deaths in severe outbreaks
Many diseases look alike. Only a laboratory test can tell them apart, so please see a veterinarian for any sick animal.
How it is diagnosed
The virus or its genes are found in blood or tonsil swabs taken while the pig has a fever, or in tissues after death. RT-PCR is often used.
Prevention and control
- Buy pigs from free herds and quarantine new animals
- Do not feed uncooked kitchen waste
- Limit visitors, vehicles and shared equipment
- Vaccines can protect pigs from signs and are used where the disease is endemic; report suspected cases to the authorities
Where this information comes from
- Classical Swine Fever (factsheet) · Center for Food Security and Public Health, Iowa State University
General information for animal owners and veterinarians, last checked October 2026. It does not replace the advice of your veterinarian, who should decide which tests and treatment your animal needs.