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Parasite Management in Goats. Dr. Beth Walker Missouri State University & Dr. Dusty Nagy University of Missouri Columbia. How do I know if I have worms?. Do you have goats/ sheep?. How do I know if I have a problem with worms?. Do you see animals with clinical signs consistent with worms?
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Parasite Management in Goats Dr. Beth Walker Missouri State University & Dr. Dusty Nagy University of Missouri Columbia
How do I know if I have worms? • Do you have goats/ sheep?
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
Age of host • Acquired immunity • Young animals more susceptible
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
Food for thought • What is the single most important tool in small ruminant medicine?
Common Problems • Stocking density • True number • Actual
Common Problems • Feed • Availability • Delivery system
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
Haemonchus contortus http://ucdnema.ucdavis.edu/imagemap/nemmap/ENT156HTML/E156haemB http://www.ksu.edu/parasitology/625tutorials/index.html
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
Coccidiosis • 3 weeks-5 months • sporadic in older animals
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
Other Enemies: Common Parasites of Sheep & Goats • Nose Bots
Other Enemies: Common Parasites of Sheep & Goats • Lice • Flies
# 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
#3: Our Strengths – Ammunition • Knowledge • Egg counts • Spring • 500 / gram = treat • Fall • 200 / gram = treat
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/