African swine fever

African swine fever (ASF) is a virus that affects pigs and wild boar and can result in high mortality rates.

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ASF is well-established within parts of Europe, Russia and China, with a reservoir of infection in the wild boar population. Focus must be on ensuring ASF does not spread further.

We urge all pig producers to ensure their biosecurity is tight, particularly vehicles, animals and people coming on to their units. We need all pig producers, farmers and the public to pull together to keep this disease out. 

Since ASF arrived in Europe in 2007, it has become clear that long-distance spread is driven by the activity of humans (humans cannot catch ASF).

Humans are also often responsible for introducing the virus into wild boar populations. Once the virus has got into wild boar, the local transmission can become self-sustaining.

If humans are responsible for the spread of ASF, we should be able to keep this disease out.

View Defra's latest outbreak assessment

Read our ASF FAQs

How to spot African swine fever (ASF)

The signs of ASF are very similar to classical swine fever.

The main clinical signs are:

  • Fever
  • Loss of appetite
  • Lack of energy
  • Sudden death with few signs beforehand

Other signs can include:

  • Vomiting
  • Diarrhoea
  • Red or dark skin, particularly on the ears and snout
  • Discharges from the eyes and nose
  • Laboured breathing and coughing
  • Abortion in pregnant sows
  • Weakness
  • Unsteady gait

There are several different strains of ASF.

Pigs infected with mild strains may not become ill or show typical clinical signs.

Severe strains of the disease are generally fatal.

All age groups are equally susceptible and mortality rates may be as high as 100%.

African swine fever is a notifiable animal disease. If you suspect it, you must report it immediately by calling the Defra Rural Services Helpline on 03000 200 301. Failure to do so is an offence.

What can you do to reduce the risk of ASF?

  • Make sure you and your staff are aware of, and adhere to, your farm biosecurity protocol
  • Ensure good biosecurity throughout the entire supply chain is the first line of defence against exotic and emerging diseases, including ASF and PEDv
  • Ensure all staff have your veterinary surgeon's telephone number, as well as the Defra Rural Services Helpline (Tel: 03000 200 301) should you suspect a case of ASF
  • Make a contingency plan in case movements become restricted

Biosecurity on pig farms

Download a template contingency plan

Download our guide to preparing a contingency plan

Biosecurity checklist on pig farms

Resources and posters

Focus must be on ensuring ASF does not spread further.

We urge all pig producers to ensure their biosecurity is tight and we have signs and posters to help which you can download and order below.

Download and order resources and posters

ASF videos


The videos below explain what ASF is, how to prevent it and the clinical signs to look out for. They also address the impact ASF could have on the industry, in terms of both commercial and rare breed pigs.

How to stay one step ahead

ASF – an introduction (part 1)

ASF clinical signs

Impact of the disease

ASF and rare pig breeds

African swine fever impact report

Read our market intelligence reports that address key questions relating to ASF, including current spread, trade restrictions and the implications of the outbreak in Belgium. They also explore the potential effects of ASF on the German market and highlight the interdependence of the European pork sector.

The latest report assesses the international opportunities and challenges, and considers the potential downward impact on prices resulting from a shift in supply and demand dynamics.

Download the report (2020)

Download the report (2018)


Useful links

Read our ASF FAQs

Biosecurity on pig farms

AHDB biosecurity hub: protect your farm against biosecurity threats

Defra ASF guidance

World Organisation for Animal Health

European Food Safety Authority guidance

National Pig Association

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