Agriculture Industry

Mike · Guest

In Europe, Post-weaning Multisystemic Wasting Syndrome (PMWS) has been with
us now since 1999.

The acute disease with high mortality has
largely passed and we are now living with the chronic form of the disease,
with varying degrees of severity in the late grower or finishing herd. In
some countries, the chronic form is considered relatively low grade,
following the implementation of challenge reduction guidelines (Madec's
principles) and changing breeds to less susceptible ones, like the Pietrain.
However, in others countries, such as the UK, it is still seen as a major
cause of mortality in finishing pigs and exerts a continuing, depressing
effect on the overall health and productivity of a herd.

The main cause of the disease and its effects is clearly associated with
Porcine Circovirus type 2 (PCV-2) infection and this is also supported by
the response to the PCV-2 vaccines, which are being used successfully in
both the USA and Canada. There are thought to be other associated
trigger/complicating factors such as Mycoplasma hyopneumoniae, PRRSV
(Porcine Reproductive and Respiratory Syndrome Virus) and even Salmonella
spp, which exacerbate the clinical problem but in Europe we are fortunate
that the US PRRSV strains are not so widespread or so virulent. Currently,
there are four PCV-2 vaccines in N. America, with one introduced for sows,
which is also available in a few countries in Europe, and three for use in
young pigs of three weeks of age. An early trial report, given at the recent
AASV meeting using a killed vaccine (Ingelvac CircoFLEX - Boehringer
Vetmedica) in young piglets has shown mortality figures in finishers
dropping to almost pre-PCV-2 infection levels, by as much as 7% (Desrosiers
and others, 2007). The vaccine was given to groups of weaners and growers,
which were free from PRRSV and M. hyopneumoniae, so the effect was just
against PCV-2 infection.

For more information, see "New PCV-2 Vaccines are on their Way"
www.octagon-services.co.uk/articles/PCV2vaccines.htm
and
"Costs of PCV-2 Infection in Finishing Pigs and Potential Benefits of
Vaccination":
www.octagon-services.co.uk/articles/PCV2costs.htm