Table 1.

Main lesions observed in the different forms of ASF [6].

Symptom	Peracute ASF	Acute ASF	Subacute ASF	Chronic ASF
Fever	High	High	Moderate	Irregular or absent
Thrombocytopenia	Absent	Absent or slight (late)	Transient	Absent
Skin	Erythema	Erythema	Erythema	Necrotic areas
Lymph nodes	–	Gastrohepatic and renal with marbled aspect	The majority of lymph nodes resemble a blood clot	Swollen
Spleen	(-)	Hyperemic splenomegaly	Partial hyperemic splenomegaly or focal infarct	Enlarged with normal color
Kidney	(-)	Petechial hemorrhages, mainly in cortex	Petechial hemorrhages in cortex, medulla and pelvis; perirenal oedema	(-)
Lung	(-)	Severe alveolar oedema	(-)	Pleuritis and pneumonia
Gall bladder	(-)	Petechial hemorrhages	Wall oedema	–
Heart	–	Hemorrhages in epicardium and endocardium	Hemorrhages in epicardium and endocardium; hydropericardium	Fibrinous pericarditis
Tonsils	–	–	–	Necrotic foci
Reproductive alteration	–	–	Abortion	Abortion