(377) Disease is normally only a problem in piglets when the virus infects the herd for the first time. It may continue infecting litters for up to 12 weeks until all sows have had sufficient time to develop an immunity and pass this protection on through the colostrum.

Clinical signs

In the early stages of acute disease piglets are born in a very weak condition and rapidly become hypoglycaemic because they are unable to get to the teat and suckle. Together with weak pigs there are a high numbers of stillbirths and late mummified ones. Newborn piglets show sticky brown material over the eyelids and very occasionally small blisters on the skin. Scour, pneumonia and coughing are commonly observed but with increasing time the quality and survivability of the piglets improves.

Diagnosis

This is based on the herd history, clinical signs both in piglets and sows and serological and virological tests.

Similar diseases

Aujeszky's disease (AD) when it first enters the herd can be confused with PRRS but nervous signs are present with AD but not with PRRS. A serological test will differentiate between the two.

Treatment

• This is aimed at preventing secondary infections, usually either respiratory or enteric until an immunity builds up.
• Piglets should be injected with either long-acting OTC or amoxycillin on days 3, 7 and 14 after farrowing.
• Electrolytes should be given to counteract dehydration.