ARCHIVE: Disease factsheet: Classical Swine Fever

The disease is notifiable: if you suspect the disease, you must immediately notify the duty vet in your local Animal Health Office.

About CSF

Classical swine fever (CSF) is a highly contagious viral disease of pigs. In its acute form the disease generally results in high morbidity and mortality.

CSF was eradicated from Great Britain in 1966. Since then there have been sporadic outbreaks in 1971 and 1986. A more serious outbreak in East Anglia in 2000 affected 16 farms.

Further information:

International situation

CSF is present in a number of countries worldwide, including in Europe. Defra monitors the occurrence of major animal disease outbreaks worldwide as an early warning to assess the risk these events may pose to the UK. See current assessments.

How to spot the disease

The clinical signs of CSF may occur in chronic, congenital, mild or acute form.  The incubation period for CSF is variable but is usually between five and ten days.

In the acute form pigs develop a high temperature (40.5 degrees C or 105 degrees F), then become dull and go off their food. Other symptoms seen can vary but will include some or all of the following:

  • Constipation followed by diarrhoea
  • Gummed-up eyes
  • Coughing
  • Blotchy discolouration of the skin
  • Abortion, still births and weak litters
  • Weakness of hindquarters
  • Nervous signs including convulsions and tremors in new born piglets

The clinical signs of CSF are similar to those for African Swine Fever and also to other pig diseases such as Porcine Dermatitis and Neopathy Syndrome.

Further information:

How is the disease spread?

CSF can be spread through:

  • Movement of infected pigs or pigs incubating the disease.
  • Movement of equipment, vehicles and people who work with pigs between pig farms with ineffective biosecurity.
  • Pigs eating infected pig meat or meat products.

Reducing the risk of disease

The UK operates strict controls over the import of meat and meat products primarily to guard against the introduction of animal diseases.  If, despite these precautions, swine fever viruses enter the country the risk of pigs becoming infected has been reduced by the ban on swill feeding introduced in May 2001 (now included in the Animal By-Products Regulations).

Should a pig become infected the spread of the disease would be limited by the controls contained in the Pigs (Records, Identification and Movement) Order 2007 (PRIMO).

Practising good biosecurity at all times can help reduce the risk of many pig diseases like CSF spreading.

Further information:

Disease Control

The text below summarises the approach that would be taken to control CSF should an incursion occur in the GB.  The GB CSF disease control strategy was developed by Defra, the Scottish Government and the Welsh Assembly Government in consultation with delivery agents and the pig industry. 

The control strategy applies to all keepers of pigs ranging from commercial producers to those keeping pigs as a hobby or pets.

Measures on suspicion of CSF

If you suspect swine fever, contact your local Animal Health Office immediately.

On notification of suspected swine fever, there is an obligation on the owner or keeper of the pigs not to move anything or allow anything to move from the premises that might spread disease. The following will happen:

  • an Animal Health Inspector will then visit the premises and carry out a clinical examination
  • if they suspect swine fever they will take samples for testing for both Classical Swine Fever and African Swine Fever and restrictions will be imposed on the premises.  This will mean no pigs may move on or off the premises. The restrictions will also apply to carcasses, equipment, vehicles etc.
  • a temporary control zone may be declared around a suspect premises to minimise the risk of undetected spread if the situation warrants this.

Measures on confirmation of CSF

If an animal is confirmed to have CSF, a Veterinary Inspector will issue a Restriction Notice confirming disease.  The premises is now known as an Infected Premises (IP). The following will happen as quickly as possible:

  • Valuation – all pigs will be valued by a Defra appointed valuer.  
  • Culling – all pigs on the premises will be humanely culled.
  • Disposal – Carcases will be disposed of, usually through rendering or incineration though other options are available.
  • Preliminary Disinfection – this is a disinfectant spray of all parts of the premises where pigs have been to damp down virus to minimise the risk of spread of disease.
  • Veterinary investigation –  to establish where the disease came from and where it may have spread.

In accordance with Schedule 3 of the Animal Health Act 1981, compensation for an animal infected with CSF will be half the value of the animal immediately before it became infected, and in every other case the compensation will be the value of the animal immediately before it was slaughtered.

As a result of the veterinary investigation, other premises may be identified as where the disease may have come from (source) or gone to (spread). These linked premises are termed dangerous contacts and could be many miles from the IP. These premises will be placed under restrictions. Where the veterinary inspector considers the risk of exposure to virus to be high and taking account of epidemiological evidence, pigs at dangerous contact premises may be slaughtered on suspicion.

On all infected premises, cleansing and disinfection (C & D) must take place before new animals can be brought on to restock. Secondary C & D will be done at the owner’s expense though Animal Health Veterinary Inspectors will supervise the process and will need to be satisfied that it has been undertaken to a satisfactory standard.

Further information:

Controls in the surrounding area

A protection and surveillance zone will be imposed around an infected premises (a minimum of 3 and 10km respectively).  Control measures will be applied in these zones to minimise the risk of disease spread, including restrictions on:

  • The movement of live pigs off or on to the premises;
  • The movement of pig genetic material such as semen, ova, embryos;
  • The movement of other things likely to spread disease such as carcases, pig products, waste etc.

These restrictions will be eased based on the disease situation but EC law also sets out minimum periods for allowing movements.  Generally no movements will be authorised in the protection zone before 30 days have elapsed since preliminary cleansing and disinfection of infected premises or 21 days in the surveillance zone.

The protection and surveillance zones will not be lifted until the following have been satisfied:

  • Cleansing and disinfection of all IPs within the zone have been completed; and,
  • All holdings with pigs in the PZ and SZ have undergone veterinary surveillance and premises in the PZ have had samples tested.

The final round of veterinary surveillance cannot take place until 30 days in the case of the PZ and 20 days in the case of the SZ after the completion of preliminary cleansing and disinfection on the IP.

Further information:

Measures when CSF is suspected or confirmed in feral pigs

Feral pigs refers to Sus scrofa whether they are domestic pigs living in the wild, wild boar or hybrid animals which are living free in GB.  If CSF is suspected or confirmed in feral pigs certain control measures may apply to farms in the surrounding area.

For example, if CSF is confirmed in feral pigs, restrictions will apply on the movement of domestic pigs off/ on to premises within the feral pig infected area. If CSF is confirmed in feral pigs, the Government will take action to implement a disease eradication plan.  Restrictions on premises will be lifted following disease eradication in feral pigs.

Protection of breeds at risk

EC law allows Defra to consider special measures for the protection of pig breeds at risk or pigs bred for scientific, research, display or educational purposes (such as zoos or wildlife parks) provided that disease control is not jeopardised.  If an animal is exempted from a cull, the pig keeper will need to put in place specified mitigating measures to minimise any disease risks the exemption creates.


Vaccination is not a routine control measure.  The use of vaccination may be considered during a prolonged epidemic, where there is a dramatic increase in the number of premises where disease is being confirmed each day or in areas of very high pig density.

Contingency planning

Defra's Contingency Plan for Exotic Animal Diseases is revised annually. The plan, which covers arrangements for dealing with a range of exotic animal diseases, is produced for Defra by the Animal Health agency.


The following legislation is currently in place to control Classical Swine Fever:



Further information:

Enforcement provisions

Local Authorities will execute and enforce the provisions of the Classical Swine Fever (England) Order 2003, other than where the legislation makes specific provisions otherwise. Similar policies exist for legislation in Scotland and Wales. The penalties for not complying with the legislation are detailed in Part V of the Animal Health Act of 1981.


Page last modified: March 10, 2010