Changes

===Clinical Signs===

===Clinical Signs===

The clinical signs of PRRS vary with the strain of virus, the immune status of the herd and management

The clinical signs of PRRS vary with the strain of virus as well as the the immune status of the herd. Although infection may be asymptomatic, a wide variety of signs can be seen in all ages of pig. In adults, a period of acute disease is seen, which is characterised by lethargy, inappetance and pyrexia. Abortion or premature farrowing may be seen, and severe cases may result in the death of up to 10% of animals. Vestibular signs, such as loss of balance or a head tilt, occur in some cases.

factors. Infection may also be asymptomatic. Clinical disease in a herd is a consequence of acute viraemia in

 

individuals and transplacental transmission of virus from viraemic dams to their foetuses, which can occur at

Concurrent infections

any time, though infections in the last third of pregnancy can result in severe disease. Concurrent infections

with other pathogens are also common.

with other pathogens are also common.