The incubation period for African swine fever varies between 2 and 10 days, depending on the virulence of the virus. Clinical symptoms may look very much like those of classical swine fever. Laboratory tests are always essential to make a definitive diagnosis. Wageningen Bioveterinary Research conducts these tests.
Clinical symptoms may look very much like those of classical swine fever: fever, listless pigs, lack of appetite, red skin, (bloody) diarrhoea, vomiting. Bleeding, cyanosis (blue skin) and necrosis of parts of the skin (blackening) may occur. Sows may abort upon infection. Pigs may suddenly die without symptoms being observed beforehand.
African swine fever mortality rate
Domestic pigs soon suffer serious symptoms, with a high percentage mortality of up to 100%. However, there are strains of the virus that result in a lower mortality rate, but usually still between 30 and 70%.
Pigs surviving the acute phase may apparently recover. But they may remain carriers of the virus - for several months. The symptoms may initially disappear, and can return at a later stage.