Changes

In the acute form, animals are almost always pyrexic. In piglets the fever may exceed 40°, but in adults temperatures may be no higher than 39.5°. Lethargy, conjunctivitis, lymphomegaly may be seen, as well as respiratory signs and diarrhoea. Neurological signs such as gait abnormalities, incoordination and convulsions are also common. The most telling sign of classical swine fever is haemorrhage of the skin. These arise in the second or third week post-infection on the ear, tail, abdomen and medial aspect of the limbs and persist until death. CSF virus also causes severe leukopenia and immunosuppression, which can to secondary enteric or respiratory infections which may cause confusion by masking or overlapping the more typical signs of CSF. With increasing age of infected animals, the clinical signs of acute CSF become less specific and diagnosis more difficult. Alao, acute classical swine fever is indistinguishable from African swine fever and so care must be taken when formulating a diagnosis. Other differential diagnoses for acute CSF are erysipelas, PRRS, purpura haemorragica, PWMS, PDNS, Salmonellosis and Pasteurellosis. Classical swine fever should also be considered in any pyrexic enteric or respiratory disease case that is not responsive to antibiotics.  

In the acute form, animals are almost always pyrexic. In piglets the fever may exceed 40°, but in adults temperatures may be no higher than 39.5°. Lethargy, conjunctivitis, lymphomegaly may be seen, as well as respiratory signs and diarrhoea. Neurological signs such as gait abnormalities, incoordination and convulsions are also common. The most telling sign of classical swine fever is haemorrhage of the skin. These arise in the second or third week post-infection on the ear, tail, abdomen and medial aspect of the limbs and persist until death. CSF virus also causes severe leukopenia and immunosuppression, which can to secondary enteric or respiratory infections which may cause confusion by masking or overlapping the more typical signs of CSF. With increasing age of infected animals, the clinical signs of acute CSF become less specific and diagnosis more difficult. Alao, acute classical swine fever is indistinguishable from African swine fever and so care must be taken when formulating a diagnosis. Other differential diagnoses for acute CSF are erysipelas, PRRS, purpura haemorragica, PWMS, PDNS, Salmonellosis and Pasteurellosis. Classical swine fever should also be considered in any pyrexic enteric or respiratory disease case that is not responsive to antibiotics.  

the chronic form of classical swine fever develops when pigs fail to mount an effective immune response to viral infection. Initially, the signs are similar to the acute form of the disease, but symptoms become less specific as the course progresses. For example, pigs may display chronic enteritis, loss of condition, lameness or intermittent pyrexia. In a herd, mortality may be increased or there may be large numbers of runty pigs. Although animals may survive some months after contracting chronic CSF, the disease is always eventually fatal and animals continue to shed virus until death.

The chronic form of classical swine fever develops when pigs fail to mount an effective immune response to viral infection. Initially, the signs are similar to the acute form of the disease, but symptoms become less specific as the course progresses. For example, pigs may display chronic enteritis, loss of condition, lameness or intermittent pyrexia. In a herd, mortality may be increased or there may be large numbers of runty pigs. Although animals may survive some months after contracting chronic CSF, the disease is always eventually fatal and animals continue to shed virus until death.

The course of infection in older, breeding-age animals is often subclinical; however, CSFV is able to cross the placenta at any stage of pregnancy. The outcome of transplacental infection is highly dependent on the stage of gestation, and also virulence. During early pregnancy, transplacental CSFV infection may cause abortions, mummifications, congenital malformations or stillbriths. Infection occuring after 50-70 days gestation can lead to the birth of persistently viraemic piglets. These may appear clinically normal at birth, but grow poorly and occasionally show congenital tremor. Persistently infected piglets also shed virus until their inevitable death, acting as a reservoir for virus and making major contributions to the maintenance of infection in the population. It is therefore important to consider classical swine fever as a differential diagnosis of reduced fertility in addition to parvovirus, PRRS, leptospirosis and Aujeszky's disease.

Although the course of infection in the sow is often

subclinical, CSF virus is able to cross the placenta of

all stages of pregnancy. The outcome of transplacental

infection of fetuses mainly depends on the

time of gestation and viral virulence, respectively.

Infection during early pregnancy may result in

abortions and stillbirths, mummification and malformations.

Infection of sows from about 50–70 days of pregnancy

can lead to the birth of persistently viraemic

piglets, which may be clinically normal at birth and

survive for several months. After birth, theymay show

poor growth, wasting or occasionally congenital tremor.

onset CSF�. These piglets constantly shed large

amounts of virus and are a dangerous virus reservoir,

spreading the disease and maintaining the infection

within the pig population (Van Oirschot and Terpstra,

1977). This situation is comparable to cattle

CSF must be considered in the differential diagnosis

of reduced fertility due to parvovirus infection,

PRRS, leptospirosis and Aujeszky�s disease.

===Laboratory Tests===

===Laboratory Tests===