Points of View
A forum for sharing perspectives from across the Canadian Sheep Industry
CANADIAN SHEEP FEDERATION
JULY 2009
VOLUME 3 • ISSUE 7
C. ovis Condemnations in Sheep – An
Emerging Problem in Canada
For the second year, we are dealing with
carcasses being condemned due to Cysticercus
ovis (C. ovis). Also known as “sheep measles,”
animals become infected by eating tapeworm
eggs (passed in the feces of dogs and wild
candids) while grazing on pasture or while
consuming contaminated stored feeds. These
eggs hatch in the sheep’s intestine and then
the larvae penetrate the intestinal wall and are
carried via the bloodstream to target tissues.
In this edition of Points of View you’ll learn
how other countries have been impacted
by C. ovis and what Canada can learn from
their experiences. We also hope to increase
your understanding of how carcasses
are condemned and raise awareness of
management techniques to help avoid this
problem in your flock.
C. ovis infection is neither reportable nor a
zoonotic disease in sheep or goats. However, it
is condemnable in the case of heavily-infected
animals. The economic losses associated with
an infection can be substantial to producers
and buyers. Ontario has experienced sporadic
outbreaks of C. ovis in feeder lambs over the
past 15 years, but in 2008 the severity of the
problem increased. There is also great concern
that if the infection becomes established in
wild canids, the disease may be difficult to
control.
POINTS OF VIEW • CANADIAN SHEEP FEDERATION
Jennifer MacTavish
(519) 824-6018
P.S. Turn to pages 5 and 6 to read about an
Ontario sheep producer who was impacted
by C. ovis. Jay Lewis from Holstein has since
implemented a number of changes in his
feedlot operation and is eager to share his
experience with fellow producers to ensure
they take the parasite seriously on their farms.
- PAGE 1 -
JULY 2009 • VOLUME 3 • ISSUE 7
What happens if we don’t deal with C. ovis?
"What this means to Canada is that it is critical to identify infected farms through carcass
inspection and provide feedback so that education efforts can be targeted to farms that
have a problem."
By Dr. Paula Menzies
While the incidence of carcass condemnations
due to C. ovis infection has skyrocketed in
Canada over the last two years, this type
of infection not new in other sheep-raising
countries. In particular, the New Zealand sheep
industry has suffered from the effects of this
parasite.
Lessons from New Zealand
C. ovis infection suddenly became more
prevalent in New Zealand when a national
program was put in place to reduce infection
by another tapeworm of dogs – Echinococcus
– which causes disease in the internal organs
of humans. Producers were instructed to feed
their dogs raw carcass meat instead of the risky
offal (liver, lungs, kidneys, etc.). The result was
a rapid climb in infection rates of C. ovis in
the 1950s and 1960s. Since then, the Meat
Industry Association (MIA) of New Zealand has
worked very hard to reduce C. ovis infections
by forming OVIS Management Ltd., a whollyowned subsidiary of the MIA, whose mission
is to provide a low-cost program promoting the
control of C. ovis.
The OVIS Management Program aims at
identifying high-prevalence farms through
accurate meat inspection of the muscle, heart
and diaphragm – and focusing education efforts
on those farms with high levels of infection.
This has been a slow and costly process but
is beginning to work as they have increased
inspection efforts to detect lower levels of
infection. On the kill line, prevalence is slowly
decreasing from an average of 1% in 1996 to
just over 0.5% in 2008.
However, one of the major issues with C. ovis
is the detection of infected carcasses. A study
from Australia in the 1970s examined carcasses
that had already passed routine inspection
POINTS OF VIEW • CANADIAN SHEEP FEDERATION
and found that 20% of “clean” carcasses were
actually infected. Another survey that followed
“clean” carcasses through to de-boning, found
an average of more than 10 cysts per carcass.
This means that many infected carcasses are
passed and so infected farms may be missed in
any routine surveillance.
The question is: are these “lightly” infected
carcasses a risk to infect dogs? Another study
found that while most cysts found on inspection
did not contain viable parasites (the parasite had
died so the cysts contained pus or were calcified
scars), approximately 1 cyst out of 13 were still
viable by the time the lambs were slaughtered.
An Action Plan for Canada
What this means to Canada is that it is critical
to identify infected farms through carcass
inspection and provide feedback so that
education efforts can be targeted to farms
that have a problem. But given that infected
carcasses may go on undetected, it is important
to stress to all producers that their flock may
be at risk. This risk of infection may be higher
in Canada than other countries because, unlike
New Zealand, it has a sizable wild canid
population that can become infected and thus
a source of infection to sheep. What may be
in Canada’s favour is that our sheep flocks are
further apart than in other countries, so farmto-farm transmission is less likely to occur.
Fortunately, only sheep and goats (and not deer)
can be intermediate hosts to this infection.
There is a lot of work to do to make sure the
Canadian sheep industry “nips” C. ovis infections
quickly by focusing on: preventing dogs and
wild canids from scavenging sheep carcasses;
thoroughly freezing or cooking any sheep or
goat meat fed to dogs; and keeping all dogs on
the farm routinely de-wormed (monthly) with a
product that is effective in killing tapeworms.
- PAGE 2 -
JULY 2009 • VOLUME 3 • ISSUE 7
Other Questions
Is it possible that only one of my
lambs has been condemned due to
C. ovis?
Yes. Here’s why:
1. If the carcass is not moderately to
heavily-infected with cysts, visual
inspection of carcasses and cutting into
rounds and shoulders may result in
missing small numbers of lesions in some
carcasses.
Figure 2. Lamb in cradle, the CSF tag cut
out from the ear is attached to the two
dressed hind legs tied up.
2. Not all abattoirs are involved in the
project with sending in tags from C.
ovis condemned animals. If lambs go to
different plants they may or may not have
tags collected after a condemnation.
3. Lambs/sheep become infected after eating
the tapeworm eggs in the environment. If
the environmental contamination is low or
limited to certain areas of the farm, then
only one or a few animals may become
infected.
Figure 3.
Lamb
confirmed as
C. ovis positive
following
veterinary
inspection –
condemned,
held tag# is
recorded and
ear tag is saved
for CSF.
Remember C. ovis is not an infectious problem.
How can I be sure CSF ear tags stay
with the carcass?
Photos courtesy Inspector Dan Babak, OMAFRA
Figure 1. Lamb in cradle, CSF ear tag
intact, ready for removal of hide.
POINTS OF VIEW • CANADIAN SHEEP FEDERATION
The process for all carcasses in provincial plants in
Ontario is that from the time of the ante-mortem
inspection of a lamb in the holding pen until the
conclusion of post-mortem inspection of that lamb,
the CSF ear tag stays with the lamb and remains
attached to the carcass until the product is
approved and stamped or it is held with a yellow
tag awaiting a veterinary disposition judgment
(i.e. may get condemned or could get approved).
- PAGE 3 -
JULY 2009 • VOLUME 3 • ISSUE 7
Letters to the Editor
"I feel the current program should have all the problems ironed out before
another voluntary, not compulsory RFID is put into effect." - Bill Duffield
Comments in relation to National
Identification and Traceability
(June Points of View)
Disease traceability is covered. USA and
overseas are satisfied... done deal. No need for
processor reply if not requested by producer. No
need for everyone to have other systems.
I agree with Lorna Wall’s comments. I feel the
current program should have all the problems
ironed out before another voluntary, not
compulsory RFID is put into effect.
Lorna Wall
Wall 2 Wall Sheep Ranch
Manitoba
I was at a slaughter house and they threw the
tags away – not even looked at or recorded. The
cattleman’s group who keeps the data is not
interested in retired tags.
Comments in relation to Scrapie Eradication
(June Points of View)
Sean McKenzie’s information of carcass data is
a pie in the sky. The average breeder on RFIDs
will never see it. My local slaughter house could
not afford the time or the equipment. Nice
thought, but not practical and too expensive.
Bill Duffield
“All sheep 18 months or older leaving your farm
or feedlot, other than those sold directly to a
federally or provincially inspected abattoir.”
The wording of this sentence...says that if you
intend for an older animal to go to slaughter it
does not need to be recorded...other than…We
need to just remove this sentence, and we have
full traceability.
OK... so my solution to the tags! Tag
all outgoing lambs. Record all outgoing
lambs and sheep. Now ewe lambs sold
as replacements are traceable to flock of
origin for scrapie, johnies, etc. and we
have full traceability for disease which
is the intent of the system and what we
have to provide for other commodity
groups to have export markets.
POINTS OF VIEW • CANADIAN SHEEP FEDERATION
Do you feel you play a role in scrapie
eradication? Yes, for now.
Do you feel you know enough about Scrapie
Canada and the Canadian Food Inspection
Agency’s (CFIA) scrapie eradication programs?
Yes.
Do you feel there is value in the Voluntary
Scrapie Flock Certification Program? If the
border opens up for Canadian ovine to USA and
Mexico.
Are you currently, or were you in the past,
enrolled in any of the programs? I was in the
Maedi-Visna for several years, but dropped out
as would not recognize a truly closed flock,
I still annually check 10% of adult ewes per
year. Note: I am also a director of the OPP
Concerned Sheep in USA.
Do you believe CSF is doing all it can to
eradicate scrapie? To a point.
What about the CFIA? They should come to the
plate with cash as USA has done. They are
dragging their behinds.
Bill Duffield
- PAGE 4 -
JULY 2009 • VOLUME 3 • ISSUE 7
PRODUCER PROFILE
Jay Lewis Takes Action Against C. Ovis
In January 2008, Jay Lewis began to have problems with his sheep. He started receiving notices
from slaughter facilities that animals going off of his farm were coming back positive for C. ovis.
Even though Jay knew the disease was not contagious, and cannot be passed from animal to
animal, he was still very concerned for the 25,000 sheep that run through his feedlot in Holstein,
Ontario on an annual basis. Instantly, Lewis felt his farm and livelihood were compromised and he
was angry. He knew his buyers would most likely reconsider working with him once they realized
his animals were being condemned, plus he’d have to find a new market to buy sheep, and in the
future, he’d have to be a lot more selective about his purchases. All of this because of a parasite
that can be easily prevented with simple farm management techniques such as de-worming dogs
and proper deadstock management.
The Cost of C. Ovis
Picking up the Pieces
“I don’t think a lot
of people realize
how serious the
situation is. In
my opinion, the
sheep industry is
one disease away
from being out of
business,” he says."
Once C. ovis had been confirmed in Lewis’ animals, things went from bad to
worse. It wasn’t long before he started to see the full cost of having C. ovis in
his sheep. Along with the condemned slips Lewis received from the slaughter
facilities, he also noticed a difference in his paycheques – they were smaller.
“The meat inspector on the kill floor would send a condemned slip for every
infected animal, subtracting each infected animal from my paycheque,” he
says. Since 2008, Lewis estimates he has lost approximately $100,000 worth of
lambs due to C. ovis. “When you’re shipping 200 lambs at a time and 10% of
them are coming back positive, it doesn’t take long to add up,” says Lewis.
If his business was going to survive, Lewis knew he had to drive on, but
moving forward presented many challenges. The first step was to find a new
seller who could guarantee healthy animals. He began by changing where he
purchased his sheep. Looking for a new market eventually led Lewis south
to the United States. “I didn’t want to go to the U.S. but I felt like I didn’t have
any other choice. I am shipping American lambs and they’re not getting
condemned so that’s who I am going to continue working with,” he says.
As his initial worries of losing buyers had become a reality, Lewis’ next step was
finding new contracts for his sheep and this was not easy. “I lost buyers that I
had been dealing with for five and seven years. I literally had to go and beg to
get some of them back,” says Lewis. With healthy animals coming in and going
out, things are starting to turn back around for Lewis but it’s been a hard and
expensive road. “We’re doing okay now, but I’ll tell you one thing, it sure takes
a long time to make back $100,000 in losses,” he says.
POINTS OF VIEW • CANADIAN SHEEP FEDERATION
- PAGE 5 -
JULY 2009 • VOLUME 3 • ISSUE 7
PRODUCER PROFILE
The Learning Experience
Lewis says his experience with C. ovis has taught him a lot about the Canadian
sheep industry especially when it comes to traceability. “When we found
out we had C. ovis on the farm, my first thought was to source where it had
come from and inform the producer. This way, the dogs could be treated
and hopefully the problem could be stopped at its place of origin,” he says.
But unfortunately, this turned out to be a lot easier said than done. Lewis
attempted to run his own traceability system but finding information proved
extremely difficult, leaving him to accept that not much could be done to
rectify the situation. This frustrated Lewis and made it very clear to him that
the Canadian sheep industry had a long way to go in terms of traceability. “I
don’t think a lot of people realize how serious the situation is. In my opinion,
the sheep industry is one disease away from being out of business,” he says.
Pointing to the U.S. sheep industry as a good example, Lewis says Canada
could learn a thing or two from their traceability system. “As soon as a U.S.
lamb walks off the truck onto my farm they are re-tagged with a RFID tag that’s
cross-referenced to their U.S. tag. I have to produce a tag manifest any time
I ship a load anywhere and I have 24 hours after shipping to report the tags,”
Lewis explains. This allows a producer to know the history behind an animal
so if something goes wrong, they can access information on where the sheep
came from. “This doesn’t happen in Canada and I think it should, but producers
are going to have to work with RFID to make it work,” says Lewis. In his opinion,
RFID should be mandatory for all Canadian sheep producers and processors,
ensuring that everyone in the industry is working with the same system. “It’s
an animal health issue, a food safety issue and it’s something the industry
needs,” he says.
A Message to Producers
“If there’s one message I could get out to producers it would be to de-worm
your dogs,” Lewis says. On his farm, dogs are de-wormed once a month to
ensure C. ovis isn’t a problem. “For producers who think it’s too expensive to
de-worm, they need to consider the costs associated with C. ovis. This includes
mortality, weight loss, condemned animals and lost buyers. When you put it
into perspective, you’ll lose a lot more money on infected animals than you
will de-worming dogs,” says Lewis. He also points to the risks around feeding
deadstock to dogs when it comes to C. ovis. “It’s just something you shouldn’t
do, but if you decide to do it anyway, all of the precautions should be taken.”
“If there’s one message I could get out to producers it would
be to de-worm your dogs,” Lewis says. On his farm, dogs are
de-wormed once a month to ensure C. ovis isn’t a problem.
“For producers who think it’s too expensive to de-worm, they
need to consider the costs associated with C. ovis.
POINTS OF VIEW • CANADIAN SHEEP FEDERATION
- PAGE 6 -
JULY 2009 • VOLUME 3 • ISSUE 7
Your feedback is essential!
The dialogue has started, but we need to hear more about what you think in order to keep this forum going. Its
success depends how much everyone in the sheep industry weighs in with their own
perspectives and suggestions for change.
Tell us:
•What you think about “Points of View”
•If you had a strong reaction – either good or bad – to the contributions or letters in this issue
•If you want to contribute to an upcoming issue
•If you have a story that would make a good case study for others to learn from
•If you have a topic you’d like to see addressed
Send your comments to [email protected] or contact Jennifer MacTavish directly by phone at 1-888684-7739 or by email at [email protected].
In the next issue...
Myth – Predation is not impacting my production
Predation has not only been cited as a major barrier to increasing sheep
production in Canada, it has also been cited as a key cause of producers
getting out of the industry entirely.
Predators such as coyotes pose a very serious threat to the continued
livelihood of many sheep producers across Canada. They are responsible for
the devastating loss of valuable livestock and farm income. The cost is high for
some provincial governments, too. In 2008, the Ontario government paid out
$1.33 million to producers (all types of livestock) for losses due to predation.
The Canadian Sheep Federation in cooperation with Canadian Sheep Breeders’
Association and Canadian Cooperative Wool Growers recently appealed to the
federal Minister of Agriculture and Agri-Food as well as the Minister of Natural
Resources to collaborate on a national approach to predation. The goal would
be to provide a clear and consistent framework for dealing with predation
issues across Canada, while providing sheep farmers with effective, practical
tools to protect their flocks and livelihood.
•Does predation affect your operation?
o How severe is the risk?
o What kinds of predators do you face?
o What control methods do you use and how successful are they?
o What costs do you incur for predation control?
•Has predation limited your growth?
•Are you compensated for losses due to predation?
o If so, is the compensation adequate?
o How can current programs be improved?
•How do you record losses due to predation?
•What new tools do you need to prevent and manage predators?
•How do you feel about a National Strategy on Predation?
•What do you believe is CSF’s role in predation control? What is the role of
the federal and provincial government?
Send your comments to [email protected], or contact Jennifer
MacTavish directly at 1-888-684-7739 or [email protected].
POINTS OF VIEW • CANADIAN SHEEP FEDERATION
- PAGE 7 -
JULY 2009 • VOLUME 3 • ISSUE 7