PMWS 03 sw


Post-weaning Multisystemic Wasting Syndrome of Swine Treatment and Control

Personal observations:   John Carr BVSc PhD DPM DiplECPHM MRCVS


Vaccine therapy using Circovirus vaccines have had dramatic results in mitigating the effect of Post-weaning Multisystemic Wasting Syndrome (PMWS).  However, it is still essential that management is enhanced to mitigate the long term effects of PMWS, especially while these vaccines are still in their infancy and availability is extremely limited.



The major stumbling block for producers will be the term PMWS.  For the last 10 years, most North American producers will have had PMWS diagnosed on their farms.  This condition is however, nothing like the condition called PMWS in Europe and Asia.  In October 2004 problems, resembling European PMWS, started in Quebec, Canada.  This condition has spread progressively westwards, northwards and south into the United States and is now recognized in Chile.


The clinical signs in an individual pig and even in a group of pigs can be very similar between traditional PMWS and the more aggressive “epidemic” form of European PMWS.  In the European form of PMWS, the condition can be devastating to the stock and occurs in batch after batch and is generally none responsive to medication or small management improvements.  This condition is contagious, whereas the traditional form does not exhibit contagious characteristics.

There are numerous problems with diagnosis given the mistake that PMWS can exist in an individual pig on a farm with no history of PMWS.  This is associated with a confusion over the role of PCV2 and PMWS in producing histological signs.


The paper is divided into several sections:




Clinical findings



Gross pathological findings



Laboratory findings

Herd History



Treatment and control

PMWS negative

PMWS positive

PCV2 vaccines