Classical Swine Fever | Clinical Signs
Acute and chronic courses of CSF are recognized. Clinical manifestations depend on the age of the animal and virulence of a particular viral strain. Mortality rates may reach 90% in young animals, whereas in older pigs the disease may be mild or even subclinical.
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Initial clinical signs include depression and high fever (41°C/106°F), which are associated with severe leukopenia (total white blood cell count may be less than 4,000/mm3).
The virus attacks lymphoid tissue and tonsillar necrosis, appearing as popcorn-like spots in the dorsocaudal pharynx may be visible clinically (see photo). |
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Erythema, hemorrhage and cyanosis are observed in white-skinned animals, particularly at the extremities, abdomen, axillae and inner side of the legs. Petechial hemorrhages are also seen in mucosae although this finding is not detected consistently.
<< Hemorrhage of the ocular mucosa |
Nervous signs are often observed and include lethargy, occasional convulsions, grinding of the teeth, and difficulty in locomotion.
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Susceptible animals usually die within less than 10 days after the initial signs of the disease. Those that survive longer may develop signs of respiratory and intestinal involvement, characterized initially by constipation followed by diarrhea.
In the chronic manifestation, after the initial febrile manifestation, the animals have a transient recovery followed by recurrence with fever, anorexia and depression. |
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Natural exposure to the virus during gestation may result in a wide variety of fetal and neonatal abnormalities which include: abortion, mummification, anasarca, ascities, still-birth, cerebellar hypoplasia, hypomyelinogenesis, congenital tremors and neonatal death.
Infection at early gestational stages (before the 20th day of gestation) may result in embryonic death and absorption. |
Gross Lesions >> |
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