Alpacas Magazine - 2010 Spring

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New Test Available for Barber Pole Worms
(Haemonchus Contortus)
By David Stauth, Oregon State University
Researchers at Oregon State University
and the University of Georgia have devel-
oped an improved, more efficient method
to test for the most serious of the parasitic
worms in sheep and camelids, a problem
that causes hundreds of millions of dollars
in losses every year to the global sheep
and wool industry.
This technology is now available, and
will allow a faster, easier, and less expen-
sive way to test for the presence and
quantity of Haemonchus contortus, or
“barber pole” worms, a species that is
very pathogenic to sheep, goats, alpacas,
and llamas. This will help sheep ranchers
deal with this problem more quickly and
effectively, optimize their management
practices, and sometimes avoid costly
therapies.
Findings about the new test were just
published in Veterinary Parasitology, a
professional journal.
“This particular parasite is much more
pathogenic in sheep than other worms, and
previous methods to detect it were very
labor intensive and often not commercially
practical,” said Michael Kent, an OSU pro-
fessor of microbiology. “Now ranchers and
veterinarians can test for this problem and
target their management or treatment
strategies much more effectively.”
This parasite causes significant produc-
tion losses, and in some cases it’s the
limiting factor to sheep production on
pasture lands. The nematodes can cause
internal bleeding, which in turn can lead
to anemia, poor food conversion and
growth, low protein levels, reduced lamb
production and wool yield, and in some
cases death.
Known as the barber pole or wire
worm, Haemonchus contortus is a blood-
sucking parasite that pierces the lining
of the sheep’s stomach. It’s a prolific egg
producer, releasing up to 10,000 eggs per
day, and often causes problems in warmer
climates or during the summer. Once an
infection is demonstrated, expensive treat-
ments, or complex management strategies
are often needed to address it.
The new lectin staining test is based on
a peanut agglutinin that binds to eggs of
the parasite and can be easily visualized
with a microscope using ultraviolet light.
It’s an improved version of previous tech-
nology developed by scientists in Australia
that was slower, less effective, more expen-
sive and required more advanced training
to perform, researchers say.
The relatively inexpensive test was
developed by microbiologists and veteri-
nary doctors at OSU and UGA, and is
now available through those institutions.
Its use should continue to expand and
become more readily available around the
world, Kent said.
The test may also be of special value to
ranchers interested in organic production
of sheep, goats, alpacas and llamas, who
try to avoid use of chemical treatments in
maintaining the health of their animals.
“One of the current testing tools com-
monly used by sheep and goat farmers
in dealing with H. contortus is the
FAMACHA method, in which the farmer
compares the animal’s lower eyelid color
to swatches on a card to determine the
animal’s anemia status,” said Bob Storey,
a UGA researcher who co-developed the
lectin staining test. “This method only
works in situations where H. contortus is
the primary parasite in a given herd’s
worm population. The new lectin staining
test allows for a faster and less expensive
method of determining the predominance
of H. contortus in a herd worm popula-
tion, thereby making it easier for produc-
ers to determine if FAMACHA can be a
useful tool for them. Additionally, for the
veterinarian dealing with an anemic ani-
mal and a heavy parasite burden, the
lectin staining test provides quick feed-
back as to whether the anemia is parasite-
based or may be due to another cause.”
The test requires only a small amount of
feces, and results are available in as little as
two days. Anyone interested in obtaining
the test can get information on sampling,
test results and fees from the Veterinary
Diagnostic Laboratory at OSU1
or 541/752-5501), or Bob Storey
(Dept. of Infectious Diseases, College
of Veterinary Medicine, University of
Georgia, Athens, Ga., 30602 or 706/
542-0195). FAMACHA information can
be obtained through Bob Storey or by
sending an email to .
As with any animal health concerns,
results should be reviewed with a veteri-
narian so that proper treatment programs
can be put in place, researchers said.
About Oregon State University: OSU is one of
only two U.S. universities designated a land-,
sea-, space- and sun-grant institution. OSU is
also Oregon’s only university designated in the
Carnegie Foundation’s top tier for research
124 Alpacas Magazine
Reprinted by permission from Oregon State University; further reprinting is allowed. 541/737-0787,
Contacts: Michael Kent, 541/737-8652, Bob Storey, 706/542-0195,
Oregon State Univ. Press Release, January 5, 2010
under the
microscope