African Swine Fever

Differential Clinical Diagnosis

Differential diagnosis is carried out on diseases in which skin lesions are easily mistaken for those of African Swine Fever. The most important differential diagnoses are Classical Swine Fever, Swine Cholera, Erysipelas, acute Salmonellosis and Aujeszky's disease orPseudorabies and the Porcine Dermatitis-Nephropathy Syndrome.

Table 1: Signs and lesions that are differential with ASF
Disease Affected species Signs Lessions
Coinciding Differential Coinciding Differential

Classical Swine Fever


Fever, depression

Longer clinical course than ASF

Cutaneous and renal haemorrhaging, and in the lymphatic ganglia.

Ulcers in the caecum and colon, marginal infarct in the spleen (Fig.39), pale renal parenchyma, non-purulent meningoencephalitis.
(Fig. 40 and 41)

Acute salmonellosis
Pigs Swine Fever, abortions. Yellowish liquid diahrroea, low morbidity and high mortality. Cyanosis on the tips of the ears, tail, trotters and abdomen, haemorrhaging in the renal cortex, splenomegaly. Focal hepatic necrosis, serous or necrotic enterocolitis.
(Swine Erysipelas)
Pigs Swine fever. Chronic forms of arthritis. Splenomegaly, petechiae in the renal cortex, ganglionar hypertrophy with tumefaction and haemorrhaging. Romboid urticariform lesions on the skin. Arthritis and vegetative endocarditis.
Dermatitis-nephropathy syndrome Pigs (See lesions) Non-specific, slight hyperthermia, weakness Purple-red marks on the skin of the hams, ears, abdomen and perineum. Renal petechiae. Lesions caused by necrotising vasculitis. Pale kidneys despite petechiae.
Aujeszky´s disease. Pigs, ruminants, rodents and carnivores. Abortions (Fig. 42), cutaneous cyanosis in piglets.
Nervous signs Pneumonia. Necrotic enteritis.


Table 2: Signs and lesions according to the virulence of the isolate.
ASFV virulence
Incubation period
Clinical course Clinical signs Mortality
High virulence 2-3 days 1-4 days Sudden death with no signs of encephalitis or fever, prostration, skin alterations. 90-100%
Moderate virulence 2-3 days 7-20 days Typical signs of ASF: fever, prostration, lack of appetite, skin alterations.
Abortions and high mortality in mothers.
> ó = 60%
Low virulence 2-3 days 15-21 days Multifocal cutaneous necrosis, painful inflammation of the carpus and tarsus.
Abortions. Seroconversion. It may be inapparent.
< ó = 10%


Fig. 39: Normal spleen (below),
haemorragic ASF infected spleen (medium),
CSF spleen (above)

Fig. 40: Classical Swine Fever.
Brain. Perivascular cuffing
in non-purulent meningoencephalitis
characteristic in CSF.

Fig. 41: CSF. Brain. Non-purulent
meningoencephalitis. Enlarged meninge
due to inflammatory lymphocyte

Fig. 42: Aujeszky´s disease.
Abortions in the second third of gestation.
Macerated foetus.

Fig. 43: Aujeszky's disease.
Cyanosis in the hams of
an affected piglet.