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

Haemonchus contortus

http://www.ksu.edu/parasitology/625tutorials/index.html

http://ucdnema.ucdavis.edu/imagemap/nemmap/ENT156HTML/E156haemB

Haemonchus contortus

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

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

http://www.biosci.ohio-state.edu/~parasite/life_cycles.html

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

Tapeworm

Tapeworm

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

• http://www.biosci.ohio-state.edu/~parasite/life_cycles.html

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

• 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…– Pastures– Species– Herd– Budget

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#4: Proper Management

• Manage our…– Herd

#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