Better Pork - October 2016

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30 Better Pork October 2016
HERDHEALTH
Seneca Valley Virus (SVV), now
called Senecavirus A (SV-A), is a
non-enveloped, single-stranded
RNA virus in the family Picornaviri-
dae, which is the same virus family as
Porcine Epidemic Diarrhea (PED) vi-
rus, Foot-and-Mouth Disease (FMD)
virus and Swine Vesicular Disease
(SVD) virus. The disease from SVV/
SV-A clinically resembles FMD,
SVD, Vesicular Stomatitis (VS) and
Vesicular Exanthema (VE), all of
which are vesicular diseases of pigs
(and other livestock species) and are
reportable foreign animal diseases
(FADs) that would have devastating
consequences if any of them were
to occur in our Canadian livestock
population.
SVV/ SV-A is not a new virus. It
has been reported in past years in the
United States, New Zealand, Austra-
lia and Canada. The one report from
Canada was made in 2007 when 187
pigs shipped from Manitoba to a U.S.
slaughter plant arrived with vesicles
(fluid-filled cysts) on the snout and
feet, and 80 per cent of the 187 pigs
were clinically lame on the truck,
causing an alarm to be raised since
the clinical signs were consistent with
FMD. Tests conducted by the U.S.
Foreign Animal Disease Diagnostic
Laboratory at Plum Island were nega-
tive by polymerase chain reaction
(PCR) for all FADs (FMD, SVD, VS
and VE), but were positive for SVV.
Clinical signs of Senecavirus A
Clinical signs of SVV/ SV-A are
similar to those of the reportable
vesicular diseases FMD, SVD, VS and
VE, characterized by the formation
of vesicles, erosions and ulcers on the
skin, oral cavity and coronary band
at the hoof/skin junction on the feet.
Lesions can be seen in all ages of pigs,
including sucklers, weaners, growers,
finishers and mature sows and boars.
An increase in mortality in neonatal
pigs up to one week of age can be
expected. Pre-weaning mortality of
30 to 70 per cent might occur in the
early stages of an outbreak of SVV/
SV-A, but clinical signs usually cease
in about a week.
One feature about SVV/ SV-A that
differentiates it is that, unlike most
other viruses, SVV/ SV-A prefers
warm environmental conditions and
does not like cold. Hence, it is much
more active and outbreaks are more
common in the spring through to
the fall rather than over the winter
months.
As diseases go, SVV/ SV-A is not
a particularly severe disease to the
affected pigs. With the exception of
an outbreak in Brazil (described on
page 31), illnesses have been clini-
Seneca Valley Virus symptomsmimicmore serious
foreign animal diseases
If you see vesicles on your pigs, immediately consult your herd veterinarian.
by S. ERNEST SANFORD
dusanpetkovic/Creative RF/Getty Images
Seneca Valley virus is not new. It has
been reported in past years in the
United States, New Zealand, Australia
and Canada.