FYI-Management of Barber pole Worm in Sheep and Goats in the Southern U.S.

Discussion in 'Sheep' started by shepmom, Oct 10, 2005.

  1. shepmom

    shepmom Well-Known Member

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    825
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    May 29, 2003
    Location:
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    > http://attra.ncat.org/downloads/goat_barber_pole.pdf
    > > Management of Barber pole Worm in Sheep and Goats
    > in
    > > the Southern U.S.
    > >
    > > Joan Burke
    > >
    > > Research Animal Scientist
    > >
    > > USDA, ARS, Dale Bumpers Small Farms Research
    > Center,
    > > Booneville, AR
    > >
    > > This publication will address management of
    > > Haemonchus contortus or barber pole
    > >
    > > worm, which is the parasitic nematode responsible
    > > for anemia, bottle jaw, and death of
    > >
    > > infected sheep and goats mainly during summer
    > months
    > > in warm, humid climates.
    > >
    > > Recommendations are based on current research
    > > findings and are subject to revision as
    > >
    > > we learn more about the biology of the parasite
    > and
    > > host and alternative products that
    > >
    > > may act as anthelmintics.
    > >
    > > Biology of H. contortus
    > >
    > > First a little background on what is known on the
    > > biology of H. contortus. This parasite
    > >
    > > has a relatively short life cycle of approximately
    > > three weeks and thrives in warm, humid
    > >
    > > conditions. Grazing animals pick up infective
    > larvae
    > > on forages that are relatively short.
    > >
    > > Early to mid-morning forages contain the most
    > larvae
    > > on its dew covered tips. As the
    > >
    > > forage dries, the larvae migrate back to the moist
    > > soil or coil up and slowly dry out (but
    > >
    > > can survive for a relatively long period of time
    > in
    > > this dehydrated stage and once
    > >
    > > moistened can re-hydrate and become motile again).
    > > Once in the rumen the larvae
    > >
    > > continue development, travel to the abomasum, or
    > > true stomach, and become adults. The
    > >
    > > adult female can lay thousands of eggs daily and
    > can
    > > consume 200 microliters of blood
    > >
    > > daily. An average of 10,000 adults is enough to
    > kill
    > > a sheep or goat. The female’s
    > >
    > > prodigious output of eggs is partly responsible
    > for
    > > the explosive nature of outbreaks,
    > >
    > > especially in favorable weather conditions. The
    > eggs
    > > are deposited in the feces, hatch on
    > >
    > > pasture and the life cycle begins again. Outbreaks
    > > are worst when warm summer rains
    > >
    > > break up the fecal pellet and create a moist
    > > environment for the hatched larvae. During
    > >
    > > drought or very cold conditions, a majority of
    > > larvae become dormant or die and
    > >
    > > transmission to the animal is very low.
    > >
     
  2. shepmom

    shepmom Well-Known Member

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    Location:
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    > > Drug Resistance
    > >
    > > Different populations of the parasite have
    > developed
    > > resistance to all available
    > >
    > > pharmaceutical dewormers, ranging from low to
    > > complete resistance. This means that
    > >
    > > dewormers are not effective in reducing the adult
    > > worm population. The highest
    > >
    > > resistance has been observed with ivermectin
    > > (Ivomec®) and albendazole (Valbazen®)
    > >
    > > or fenbendezol (SafeGuard® or Panacur®) and low to
    > > moderate resistance has been
    > >
    > > observed with levamisole (Levasol®, Tramisol®).
    > > Resistance to moxidectin
    > >
    > > (Cydectin®) is prevalent and increasing on many
    > > farms. Moxidectin should not be used
    > >
    > > on farms unless selective treatment (treatment of
    > a
    > > limited number of animals) is
    > >
    > > practiced. If moxidectin is used on all animals at
    > > once development of resistance will be
    > >
    > > accelerated.
    > >
    > > Resistance has developed because past
    > > recommendations did not consider refugia, which
    > >
    > > is the proportion of a population of worms that
    > are
    > > sensitive to dewormers or in "refuge"
    > >
    > > from a dewormer. When treating all animals in a
    > > flock/herd as has been practiced in the
    > >
    > > past, only resistant worms survive. If these
    > animals
    > > are moved to a "clean" pasture (one
    > >
    > > that has not been exposed to sheep/goats for four
    > to
    > > six months or longer or has had hay
    > >
    > > removed from it) only resistant worms can develop
    > in
    > > that pasture. However, if only
    > >
    > > animals in need are treated, and they then go back
    > > to a "dirty" pasture of low to moderate
    > >
    > > level of pasture infectivity, as now currently
    > > recommended, the resistant worms can breed
    > >
    > > with sensitive worms and maintain a worm
    > population
    > > that should still respond to
    > >
    > > dewormers. In other words, the population of worms
    > > in refugia provides a pool of genes
    > >
    > > to dilute the resistant genes. This is the most
    > > important component of maintenance of a
    > >
    > > population of worms that will remain susceptible
    > to
    > > dewormers. Past recommendations
    > >
    > > included deworming ewes over winter. We now know
    > > that this leads to survival of
    > >
    > > resistant worms and in the spring an outbreak of a
    > > more resistant H. contortus can occur.
    > >
    > > Current recommendations include treatment of only
    > > animals in need (selective treatment).
    > >
    > > Untreated animals will harbor sensitive worms.
    > >
    > > Selective Treatment/FAMACHA
    > >
    > > Selective treatment or deciding which animals to
    > > deworm can be decided by the use of
    > >
    > > FAMACHA. FAMACHA was developed by a group of
    > > veterinarians and scientists in
    > >
    > > South Africa and was validated in the southern
    > U.S.
    > > by members of the Southern
    > >
    > > Consortium for Small Ruminant Parasite Control
    > > (SCSRPC; www.scsrpc.org). A
    > >
    > > complete description of FAMACHA can be found on
    > the
    > > website. Briefly, FAMACHA
    > >
    > > is a tool used by farmers that consists of
    > examining
    > > the color of the lower eyelid,
    > >
    > > matching the color on a chart that ranges from red
    > > or healthy to almost white or anemic.
    > >
    > > The lighter the color, the more anemic an animal
    > is.
    > > Anemia occurs as a result of the
    > >
    > > adult worm removing more blood than the animal can
    > > replace. There may be other
    > >
    > > causes of anemia, so the farmer must be aware of
    > the
    > > health and nutrition status of the
    > >
    > > flock/herd. Animals with red color can be left
    > > untreated, whereas paler scores indicate
    > >
    > > that an animal should be treated. Determining the
    > > need for deworming based on other
    > >
    > > criteria is being researched and include measures
    > > such as fecal egg counts (FEC), body
    > >
    > > condition scores (BCS), or weight change. Research
    > > indicates that 20% of the flock/herd
    > >
    > > carry 80% of the worms. Or in other words, 20% of
    > > the animals consistently are more
    > >
    > > susceptible to infection with H. contortus, carry
    > > the worms, and distribute the eggs in the
    > >
    > > pasture. Identification of these animals is
    > possible
    > > partly through the use of FAMACHA
    > >
    > > and these animals can be culled or removed from
    > the
    > > population. It is possible to develop
    > >
    > > a more resistant group of animals that need less
    > > frequent treatment for parasites.
    > >
    > > FAMACHA examination should occur more frequently
    > on
    > > weaned lambs/kids and late
    > >
    > > pregnant/early lactation ewes/does. The immune
    > > system becomes depressed around the
    > >
    > > time of lambing/kidding, which leaves the animal
    > > more susceptible to parasites. Also,
    > >
    > > watch for signs of an infection such as bottle jaw
    > > or animals that lag behind.
    > >
     

  3. shepmom

    shepmom Well-Known Member

    Messages:
    825
    Joined:
    May 29, 2003
    Location:
    USA
    > > Other Control Methods
    > >
    > > There are a variety of other parasite control
    > > measures farmers can use in addition to
    > >
    > > anthelmintics. Farmers may use a combination of
    > > methods and must be thoroughly
    > >
    > > familiar with the advantages, disadvantages, and
    > > risks of each. Some of these include the
    > >
    > > use of tannin-rich forages such as sericea
    > > lespedeza, copper oxide wire particles, mixed
    > >
    > > species grazing, grazing browse rather than grass,
    > > and supplemental feeding. Recently
    > >
    > > there has been some success in reducing FEC and
    > > perhaps the adult worm numbers by
    > >
    > > feeding sericea lespedeza, either fresh or as hay.
    > > Animals prefer the young plant, but it
    > >
    > > should not be grazed until it is at least six
    > inches
    > > in height to preserve the plant. Overmature
    > >
    > > plants may lose the ability to reduce infection
    > with
    > > H. contortus. More research is
    > >
    > > being conducted in these areas.
    > >
    > > Copper oxide wire particles have been used to
    > > markedly reduce infection with H.
    > >
    > > contortus in lambs. Copper oxide is very different
    > > from copper sulfate, which when fed
    > >
    > > to sheep can quickly lead to copper toxicity.
    > Copper
    > > oxide is given to animals as a bolus
    > >
    > > (not more than 2 grams) and should not be used
    > more
    > > than one time per year per animal
    > >
    > > for sheep until more is learned on reducing the
    > > potential for copper toxicity during its use.
    > >
    > > Copper oxide is available for cattle as a
    > supplement
    > > to alleviate copper deficiency.
    > >
    > > Copper oxide has been used in sheep for the same
    > > purpose. In some areas of the U.S.
    > >
    > > copper oxide should not be used because of the
    > high
    > > levels of copper in the environment.
    > >
    > > Also, some breeds of sheep may be more susceptible
    > > to copper toxicity than others (Texel
    > >
    > > and dairy breeds). Copper oxide has also been used
    > > with mixed results in goats to reduce
    > >
    > > infection with H. contortus. Copper oxide appears
    > to
    > > be effective in reducing FEC for at
    > >
    > > least a four week period and does not appear to be
    > > effective in reducing other intestinal
    > >
    > > worms. It may not be effective in all animals and
    > it
    > > may be too slow to work in severe
    > >
    > > cases. If producers want to consider this option
    > > they must seek professional advice to
    > >
    > > assess farm conditions, feeding programs, and
    > other
    > > management and environmental
    > >
    > > factors that will affect copper oxide metabolism.
    > >
    > > In drier weather, wet patches around leaky
    > drinking
    > > troughs, marshy areas or grass pens
    > >
    > > where animals are kept regularly may lead to an
    > > unexpected buildup of worms.
    > >
    > > Eliminate these factors or fence off.
    > >
    > > There are several grazing strategies that can
    > > minimize pasture contamination of larvae.
    > >
    > > Mixed species grazing is effective in reducing the
    > > population of worms on pasture. An
    > >
    > > example of an effective grazing strategy would be
    > to
    > > allow cattle to graze pastures before
    > >
    > > sheep or goats. Mixed species does not include a
    > mix
    > > of sheep and goats because they
    > >
    > > are both affected by H. contortus. Grazing
    > resistant
    > > breeds of sheep (St. Croix, Barbado
    > >
    > > Blackbelly, Gulf Coast or Florida Natives,
    > Katahdin)
    > > with susceptible breeds, may act to
    > >
    > > "sweep" pastures and reduce contamination to
    > > susceptible animals. Goats were evolved
    > >
    > > to graze browse rather than grass. Larvae cannot
    > > reach browse plant species and goats
    > >
    > > can be maintained with a low level of parasites
    > > using this management. Goats can be
    > >
    > > extremely susceptible to parasites if grazing only
    > > grass pastures. Rotational grazing has
    > >
    > > been used successfully to minimize pasture
    > > contamination, but more research is needed
    > >
    > > for southern pastures to make proper
    > > recommendations. Overgrazing or overstocking can
    > >
    > > quickly lead to parasite problems by creating
    > large
    > > numbers of infective larvae on
    > >
    > > pasture. Avoid overstocking! Try to leave a grazed
    > > pasture to rest for as long as possible
    > >
    > > if it has to be grazed again by sheep or goats.
    > >
    > > Supplemental feeding should not be overlooked as a
    > > means to control parasites. By
    > >
    > > increasing dietary energy, protein, or both, lambs
    > > and late pregnant or lactating ewes can
    > >
    > > become less affected by parasites. The health of
    > the
    > > animal is improved and animals
    > >
    > > consume less infected pasture. The body condition
    > > score (an index of nutrition; 1 =
    > >
    > > emaciated, 5 = obese) should be above 2. A
    > complete
    > > ration has been fed to lambs at the
    > >
    > > Booneville station resulting in nearly complete
    > > reduction in fecal egg counts and reduced
    > >
    > > anemia. More research is being conducted on this
    > > diet as a creep feed.
    > >
    > > Smart Drenching
    > >
    > > Remember, if use of chemical dewormers becomes

    > > necessary, use proper dose by
    > >
    > > knowing how much an animal weighs, administer
    > drench
    > > in the back of the mouth (not on
    > >
    > > the tongue), and if possible, withhold feed from
    > > animal prior to treatment for more
    > >
    > > effective worm kill. It may sound a bit
    > overwhelming
    > > to control internal parasites
    > >
    > > without complete reliance on chemical dewormers,
    > but
    > > with a few changes in
    > >
    > > management, it is possible to control the
    > parasites
    > > and be productive. As always, contact
    > >
    > > Dr. Burke (jmburke@spa.ars.usda.gov), a
    > > veterinarian, or extension agent for help or
    > >
    > > advice if necessary. To schedule a FAMACHA
    > training
    > > session near you please contact
    > >
    > > your local extension agent (if not trained ask
    > them
    > > to see Dr. Burke).
    > >
    > > Mention of trade names or commercial products in
    > > this manuscript is solely for the
    > >
    > > purpose of providing specific information and does
    > > not imply recommendation or
    > >
    > > endorsement by the U.S. Department of Agriculture.
    > >
    > > This article can be found in Small Farms Research
    > > Update, February 2005,
    > >
    > > published by Dale Bumpers Small Farms Research
    > > Center, SPA, ARS, USDA.
    > >
     
  4. mawalla

    mawalla Well-Known Member

    Messages:
    953
    Joined:
    Oct 27, 2002
    Location:
    AR
    This is a good article. I've met Dr. Burke and she is a neat person. I actually received my St. Croix ewe from the Booneville Research Center as a "door prize" when I attended one of their Sheep and Goat Field Days. I did my FAMACHA training there. Unfortunatly, I missed this year's field day but I do recommend attendance as they are informative and fun!