African swine fever virus and signs

  • African swine fever (ASF) is one of the most severe viral diseases of pigs. It affects pigs of all ages but cannot infect humans.

  • Domestic pigs, feral pigs and European wild boar are equally susceptible to ASF.

  • No cure or vaccine currently exists for this virus.

  • ASF is recognized by the global veterinary society as one of the major threats to pig production, food security and biodiversity in the world.

  • The disease can spread through direct or indirect contact and causes high mortality.

  • The virus can persist for a long time in the environment, carcasses and in a variety of swine products.


African swine fever is a double-stranded DNA virus. It is robust and complex, and hardier than PED.

The virus is stable over a wide range of temperatures and pH. It can survive putrefaction, meat maturing, cooking, smoking, curing, air drying, salting and freezing.

The virus is infectious for:

  • 11 days in feces

  • Months in bone marrow

  • 15 weeks in chilled meat

  • > 15 weeks in frozen meat

  • 3-6 months in cured hams that have not reached high-temperature cooking.


The virus is transmitted from oral and nasal exposure and either through direct or indirect contact. Soft ticks and other stable flies can also move the disease.

  •  Directly by contact of infected pigs with healthy pigs.
  • Indirectly by contact with the virus from excretions, secretions, and infected tissues
    including the ingestions of contaminated pork or meat products, contaminated swill or
    kitchen waste, contaminated vectors such as feed, vehicles and footwear.


  • High Fever

  • Weakness and Difficulty Standing

  • Vomiting

  • Diarrhea

  • Red or blue blotches on the skin (Particularly around ears and snout)

  • Coughing or labored breathing

  • In Sow Barns: miscarriage, abortions, stillbirths, and weak litters can occur

  • High proportions of the animals with the disease will die within 10 days.

The incubation period of African swine fever is 5-15 days. There are both acute and chronic forms of ASF. Clinically the disease is characterized by hemorrhagic fever and multiple organ involvement.

If a pig survives the infection they can shed virus for up to 6 months.
If you suspect your pigs are infected with African swine fever, contact your licensed veterinarian.


The recognition and diagnosis of African swine fever can be difficult. Clinically, the disease looks identical to Classical swine fever and looks very similar to Erysipelas, Salmonellosis, Septicemic pasteurellosis and other septicemic diseases.

Find out more:

African swine fever has no impact on human health. Humans cannot catch ASF from infected pigs not can they contract the disease by eating meat from a pig infected with ASF. But humans can spread the disease and infect pigs in many ways. Find out how the disease is spreading in other countries and the risk factor to Canada.