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Classical Swine Fever - Clinical Signs

Clinical Signs of Classical Swine Fever

There are four forms of CSF - Acute, Chronic, Congenital and the Mild form in sows. The incubation period for CSF is variable but is usually between five and ten days. The clinical signs of CSF may occur in all of these forms.

The severity of the disease varies from acute and sub-acute disease outbreaks to chronic and congenital disease (where infection is passed from sow to offspring before birth, resulting in piglets that are born with the disease). The most common forms of classical swine fever are chronic or congenital disease but the signs can be mild and very variable making diagnosis difficult. The disease can also occur in a sub-clinical form, when the pigs don't appear to be sick but are still infectious to others.

The acute form results in very high death rates within 4-7 days. Mild and chronic forms may pass undetected and pigs then die from secondary infections. In its acute form the disease generally results in high morbidity and mortality with a high proportion of pigs showing signs of the disease. Symptoms seen can vary but will include some or all of the following:


  • The appearence of red or purplish skin blotching on ears, snout, limbs and abdomen
  • Fever (increases in body temperature to 40 oC )
  • Loss of appetite
  • Dullness
  • Pigs will huddle together
  • Convulsions
  • Constipation (initially), followed by vomiting and diarrhoea
  • Gummed up eyes
  • Coughing

Chronic Form

  • Dullness
  • Poor growth rate
  • Fluctuating fevers
  • Consitpated followed by diarrhoea

Affected animals may show periods of normality following these symptons and can live for more than 100 days after the ondset of infection.

Mild Form

  • Abortion or giving birth to stillborn piglets
  • Surviving piglets may be born with tremors or deformities
  • Poor growth rates

With this form of CSF, often the clinical signs are not noticable. Sometimes short periods of illness, followed by periods of recovery are seen.

More information about classical swine fever.

If you suspect Classical Swine Fever you must by law (The Classical Swine Fever (Scotland) Order 2003) contact Animal & Plant Health Agency (APHA) immediately.