The Rural Voice, 1992-12, Page 16Season's
Greetings
The
"Pellet
Pro"
• The new alternative fuel stove
• Burns corn or wood pellets
• High Efficiency
• Thermostat Controlled
• Requires No Chimney
• Gets up to 55,000 BTU of
Environmentally Friendly Heat
— SALES REPRESENTATIVES —
Don Fluney Welding
R. R. 6, SHELBURNE, Ont. LON 1S9
Tel. 925-5793
Fax 925-6224
61111
sEsso'Cs
GREED CGS
Paul Klopp
M.P.P. Huron
Parliamentary Assistant to the
Minister of Agriculture
19 Victoria Street, Clinton, NOM 1 HO
519-482-3132
1-800-668-9320
Monday - Friday
9:00 a.m. - 4:30 p.m.
12 THE RURAL VOICE
Diagnostics
PRRS (Mystery Swine Disease)
by Dr. S. Ernest Sanford
Veterinary Laboratory Services
Time for my annual update on
Mystery Swine Disease and yes, we
have yet another "new" name for
this disease. The name now being
used is Porcine Reproductive and
Respiratory Syndrome or PRRS. I
shall be using PRRS throughout
this article. Before I update, a
quick review is in order.
Since 1987 episodes of
sows developing fever
and going off feed, then
aborting and/or delivering
mummies, premature,
stillborn and weakborn
pigs have occurred in
breeding herds in most of
the large pig -producing
areas of North America,
including Ontario. Apart
from being weak, pigs born during
an outbreak often exhibit a
"thumping" respiration ... hence
the PRRS name. A virus was
suspected but was not identified
until similar outbreaks occurred in
western Europe in 1990/91. The
virus, first isolated at the Central
Veterinary Institute in Lelystad in
The Netherlands and initially called
Lelystad Virus, is now called the
PRRS virus. The PRRS virus has
since been isolated at numerous
centres in Europe and North
America.
NEW INFORMATION ON
PRRS
Information on PRRS is unfold-
ing rapidly. A few highlights on
new findings include:
1. Herds can be infected with
the PRRS virus but never show
signs of a clinical outbreak.
2. Virus can be transmitted in
the boar's semen.
3. Long after clinical signs of
infection have disappeared the virus
might still be circulating in the
nursery and grower areas of a herd.
These nursery and grower pigs
might not show any signs of
infection.
4. However, piglets weaned into
the nursery after surviving a clinical
outbreak of PRRS sometimes suffer
repeated multiple secondary
infections such as Glasser's Disease
(Haemophilus parasuis), Strep suis,
etc. that may go on for weeks and
occasionally months.
5. Even in the worst PRRS
outbreaks, however, most herds
settle down and return to normal
levels of production in about two to
four months after an outbreak.
Once the virus was isolated a
blood (serological) test
was quickly developed to
test pigs for infection with
the virus. The test is not
yet being done in Ontario,
but a special arrangement
between OMAF and the
U.S. Federal Laboratory
allows Ontario herds to be
tested at the National
Veterinary Services
Laboratory in Ames,
Iowa. Testing to date has been
targeted on herds that have
experienced problems that resemble
PRRS. Of just over 100 herds
tested so far about 60 per cent have
had one or more animals in the herd
positive to the PRRS virus.
Positive herds have all been in
southwestern Ontario; but only a
few herds in eastern Ontario have
been tested. A herd test consists
of blood from 10 animals. There
is no charge for the test but a $20
fee is levied for handling, docu-
mentation and shipping to Ames,
Iowa.
At this time clinical outbreaks in
Ontario are few and far between.
However, as happened last winter
and spring, sporadic outbreaks are
expected with the advent of the
colder months ahead. Work on
production of a vaccine is ongoing
at many centres around the world.
So far none is available.0
New
informa
no
avai
tion
w
iabie
We have tried to keep our topics
timely and informative. However,
we would welcome any suggestions
from readers for future topics. We
would also invite interested persons
to tour the facilities at the
Diagnostics Laboratory at Huron
Park. We would ask that you make
prior arrangements by phoning 228-
6691, Ext. 276.