Parasite Management in Goats Dr. Beth Walker Missouri State University & Dr. Dusty Nagy University...
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Transcript of Parasite Management in Goats Dr. Beth Walker Missouri State University & Dr. Dusty Nagy University...
Parasite Management in Goats
Dr. Beth Walker
Missouri State University
& Dr. Dusty Nagy
University of Missouri Columbia
How do I know if I have a problem with worms?
• Do you see animals with clinical signs consistent with worms?– Diarrhea?– Weight loss?– Exercise intolerance?– Pale mucus membranes?– Peripheral edema (bottle jaw)?– Poor rate of gain?
• What is your death loss in the herd?– Do you know why animals die?
Overview
• Every parasite is not created equally
• Infestation disease
• Every parasite is not treated the same
• On ounce of prevention is worth a pound of cure
Internal Parasites
• Greatest concern among producers– $$$$$$– Reproductive losses– Death
• “Prevention rather than cure”A. David Scarfe
• “Cydectin should be kept in a glass box and labeled “Open only in case of WAR”
Dr. David Pugh
Management of Parasites
What are our best defenses?
1. Knowing our enemies
2. Knowing our weaknesses
3. Knowing our strengths
4. Proper Management
Factors influencing the potential for parasitism• Temperature• Humidity• Age of host• Seasonality and pregnancy status• Pasture management system• Anthelminthic resistance• Differences among dewormers
Temperature
• Worm eggs hatch between 45 and 100°F• Freezing kills worm larvae• Worm ova progress to infective larvae in 7-21
days• Maturation is faster at higher temperatures
Humidity
• Larvae are readily destroyed by drying
• Parasitism is rare in arid climates• Pasture contamination is greatly
reduced in July and August
Pasture management systems
• Traditional pasture strategies• Multiple small paddocks• Strip grazing• Strategic (pre-turn-out) deworming• Forage harvesting strategies
Pasture management systems
• Traditional pasture strategies• Multiple small paddocks• Strip grazing• Strategic (pre-turn-out) deworming• Forage harvesting strategies
Anthelminthics
• Available products– Benzimidazole– Avermectins– Others – levamisole
• Resistance• Use of fecal examinations
– When?• FAMACHA
Control strategies and principals
• Deworming is most beneficial in neonates• Pastures are less contaminated in early
spring and mid-summer• Strategic deworming will limit pasture
contamination• Spring deworming limits pasture
contamination• Pasture rotation will limit exposure to
parasite ova
Our Enemies: Major Internal Parasites
• Haemonchus contortus• Coccidia (protozoan)• Nematodes (round worms)• Cestodes (tapeworms)• Trematodes (flukes)
# 1 on the Most Unwanted List:
• Haemonchus contortus – barber pole worm– Major cause of anemia, bottle jaw, death– Thrives in warm, humid conditions– Larvae will live on short grasses – Early to mid-morning– Will dry out but can survive until moist
conditions return– 10,000 adults can kill a sheep or goat
http://www.ksu.edu/parasitology/625tutorials/index.html
http://ucdnema.ucdavis.edu/imagemap/nemmap/ENT156HTML/E156haemB
Haemonchus contortus
Other Enemies: Common Parasites of Sheep & Goats• Coccidia • Generally host specific
– Symptoms• Diarrhea - usually bloody• High percentage of young affected• High death loss if not treated• Rapid death loss if not treated
Other Enemies: Common Parasites of Sheep & Goats
• Treatment for Coccidia • Lasalocid (Bovatec)
FDA approved Dosage: 20 gm/ton in feed or 90 gm/ton in salt
• Monensin (Rumensin) Not FDA approved Dosage: 15 gm/ton of feed throughout feeding period Precautions: May be toxic to sheep
• Amprolium (Co Rid)DecoquinateSulfa drugsNitrofurazone
Other Enemies: Common Parasites of Sheep & Goats
• Lungworm– feed on fluid in the lung– can damage lungs such to cause
bacterial pneumonia– adult lives in lung, eggs laid in
lung and coughed up then swallowed and hatch in gut
– develop and grow and migrate via to lung via lymph
Other Enemies: Common Parasites of Sheep & Goats• Whipworms• Usually not a problem
– Slow to develop (3 to 4 month life cycle)– Larvae are usually very resistant to
environmental conditions• Feed on gut contents
• Symptoms: – Rectal prolapse – Diarrhea– Loss of body condition
Other Enemies: Common Parasites of Sheep & Goats• Flat worms• Control the vector = control the problem• Tapeworm feed on gut contents
• Proglottids (egg containers) - break open and release eggs
• Eggs eaten by soil mites and hatch in soil mite • Goat eat mites on grass larvae develops in intestine
• Symptoms– Diarrhea– Straining to defecate– Segments in feces
Other Enemies: Common Parasites of Sheep & Goats• Flat worms• Control the vector (SNAIL) = control the problem• Liver fluke
– cause severe damage during migration - bacteria can invade migration path causing Blacks disease - Lifecycle - (~4 months) - within the snail
• Symptoms - – Jaundice– Enlarged Painful Abdomen– Bottle Jaw– Anemia– Poor body condition
# 2 Our Weaknesses - Poor Management
• Overgrazing– Keep their heads up
• Poor nutrition– Can’t fight parasite infestation without any
energy
• We haven’t been culling– Get rid of the goats that harbor worms– Some are genetically more prone to infestations
• We haven’t been smart dewormers– Manage correctly to decrease deworming
#3: Our Strengths – Ammunition
• Knowledge• Research• Deworming Programs• Chemical Anthelmintics• Novel Anthelmintics
• Knowledge– Egg counts– Spring
• 500 / gram = treat
– Fall• 200 / gram = treat
#3: Our Strengths – Ammunition
McMaster Egg counts
• Most common technique used • Relies on the use of a floatation fluid
in which eggs float and heavier debris in feces sinks
• Common floatation media are various salt solutions including – Saturated common salt (NaCl) – Sodium nitrate– Sugar
McMaster Egg counts
Fill each chamber of the counting slide separately going back and refilling the pipette each time.
FAMACHA
• Based upon the color of the membranes around/near the eye
• If paler than the skin under your thumbnail, consider deworming
http://www.scsrpc.org/
#3: Our Strengths – Ammunition
• Deworming Programs• “Deworming is the worst way to control parasites”
but….D.G. Pugh
• Different Strategies – Deworm every 3 weeks
• Cost $$$$$• Time• ? Utilizing hosts defenses ? • Eventually leads to resistance
#3: Our Strengths – Ammunition
• Different Strategies– Rotate Dewormers
• No longer recommended – Can cause resistance to multiple
dewormers
#3: Our Strengths – Ammunition
• Different Strategies– Strategic Deworming
• Immediately prior to or after parturition• Do not deworm and immediately turn into
clean pasture– Hold 12-24 hours
• Timed Deworming– Hold off feed 12 hours – deworm– Limit feed additional 12 hours either turn into
clean pasture or deworm again
• Deworm with multiple classes of dewormes at the same time
#3: Our Strengths – Ammunition
• Chemical Anthelmintics– Benzimidazoles (white)
• SafeguardTM
• ValbazenTM
– Imidazothiazoles (yellow)• LevamisoleTM
– Avermectins (clear/purple)• IvermectinTM
• CidectinTM
#3: Our Strengths – Ammunition
• Novel Anthelmintics– Diatomaceous earth
• Cutting edges said to cut the parasites• What is it doing to the gut???• “If you mentions DE in New Zealand or Australia,
they laugh at you” Dr. Rich Machen TAMU
• “Feel good stuff” Bill Kruesi-Vermont Sheep farmer and Vet student
• Some animals may appear healthier but that is probably due to management or minerals in the DE
#3: Our Strengths – Ammunition
• Novel Anthelmintics– Tannins
• Sericea Lespedeza • Chickory • Birdsfoot trefoil
#4: Proper Management
• Manage our…– Budget
– We are in this to make $ or at least not lose any $, if you aren’t then don’t ruin it for the rest of us
– We all need to work together
Internal Parasites
• Do my goats have internal parasites?– YES!
• Is this a bad thing?– Not necessarily
• Are some breeds more prone than others?– Yes
• Are some individual goats within my heard more susceptible to worms than others?– Definitely!!!
• What can I do?– Manage Properly and Deworm as Correctly!
National Sustainable Agriculture Information
ServiceFunded by USDA Rural Business Cooperative
ATTRA is a project of the National Center for Appropriate Technology, with offices in Montana, California, and Arkansas to better serve you.
Call 1-800-346-9140
7:00 a.m. to 7:00 p.m. CST Monday - Friday
Linda Coffey, sheep and goat specialist