integrated parasite management for small ruminants slides contributed by marguerite frongillo, steve...

Integrated Parasite Management

for Small Ruminants

Slides contributed by Marguerite Frongillo, Steve Hart, Slides contributed by Marguerite Frongillo, Steve Hart, Susan Schoenian, Mary Smith DVM and tatiana StantonSusan Schoenian, Mary Smith DVM and tatiana Stanton

Know your weapons

Effective managementEffective drug useEffective surveillance

Integrated Parasite Management (IPM)

Goal is not to create parasite-free animals. It is normal for sheep and goats to have parasites. Goal is to prevent clinical disease and production losses.

Parasite control begins with good management and common sense

Good sanitation Feeders which prevent wastage and contamination.Clean water, free from fecal matter.Not overstocking pens and pastures. Isolation and deworming of new animals in an area where you can retrieve their manure easily.

Pasture Management to reduce barber pole worm problems

Use clean or safe pastures – easy to say, difficult to implement for entire grazing cycleUse multispecies grazingUse alternative forages Make wise management decisions about pasture height, pasture rest, and pasture rotation

Use “clean or safe” pastures

What is a truly safe pasture?New pasturePasture that has been renovated with tillageA pasture that has not been grazed by sheep or goats for the past 6 to 12 months – however, worm population does start to drop sharply after 2 months.Pasture grazed solely by horses and/or cattle for the past 6 to 12 months.Pasture in which a hay, baleage or silage crop has been removed.Pasture that has been rotated with row crops.Burnt pasture

Dilute worm population by grazing multiple species

Sheep and goats share the same internal parasites, but they are different from the parasites that generally affect cattle and horses.Cattle and horses “vacuum” sheep/goat pastures. Other benefits complimentary grazing habits.

Is this multispecies grazing?Is it going to be helpful?

Alternative foragesLivestock that browse have fewer parasite problems (excepting deer worm).

Livestock grazing tall-growing forages will have less parasite problems.

80% of parasites live in the first 2 inches of the vegetation.

Grazing high-tannin forages may reduce the effects of parasitism.

Pure stands of chicory, birdsfoot trefoil, and

Sericea lespedeza have been shown to reduce

fecal egg counts and/or larval development.

Birdsfoot Trefoil

Forage Chicory Sericea

Lespedeza

Hayfield Regrowth is a safe pasture alternative in late summer and fall

Pasture Height – 80% of the internal parasites found in bottom 2 inches of vegetation

Not a big concern during first pass through your rotational pastures after winter . Big concern in later passes.

In a grazing system for small ruminants we are:

Generally trying to move animals before the pasture is below 3 inches and get back in before pasture gets too mature

Too high and mature high lignin less nutritious and palatable for small ruminants trampling losses , etcetera

Problems with intensive rotational grazing

and small ruminant parasites - In a rotational grazing system with the primary purpose of controlling worm populations, sheep/goats should not be returned to the same pasture for at least 45 to 60 daysThis conflicts with the use of intensive rotational grazing to increase the nutritional off-take from a pasture

Due to increased stocking rates and rapid grazing intervals, management intensive grazing may increase internal parasite problems in sheep and goats as the grazing season progresses.

In summaryIf animals are left in a grazing paddock for longer than 5 to 10 days, depending on weather, may be exposed to infectious larvae

Pasture rest periods to control internal parasites need to be longer than normal recommendations for either pasture health or nutritional value

Things to consider when using intensive rotational grazing

Are there safe pastures that animals can be moved onto as grazing season progresses?

Brush pasturesHayfield regrowthPastures that your cattle or horses have been grazingCrop stubble or seeded annuals

Can you disrupt the worm cycle by mowing the pasture extremely short, grazing other species, or harvesting a crop of hay or baleage before resuming grazing?

Rotational grazing in the spring appears to reduce the “barnyard effect” and delay the onset of summer

parasite problems

Barnyard EffectBarnyards with grass or other good forage Lead to high concentration of manure and internal parasites in grazing material Can contribute greatly to herd contamination with internal parasites May have a “barnyard effect” in pastures that border barn and are not rotated

Manure pile right in yard – kids born late April – barn situated in very large pasture but kids and does tend to graze right by barn where manure concentration (and worm contamination) is highest. By late July kid loss to worms and coccidia

Please note that we are talking about herds that are rotating in the spring and summer and that by late July most of these also had high worm loads

Worm eggs per gram in kids in herds that rotate vs herds that do not - State #1

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Goats free range on woodlands during the day and locked in very large compound 5 pm to 8 am compound seeded to pasture in 2004herdsman noticed in Spring 2005 that kids did not go to woods with dams, instead stayed & grazed at compound kid loss by mid July to worms and coccidia.

Please note that we are talking about herds that are rotating in the spring and summer and that by late July most of these also had high worm loads

Worm eggs per gram in kids in herds that rotate vs herds that do not - State #2

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Central graining and watering areas can also have a barnyard effect

On these two farms, shelter and grain troughs move with the herd from pasture to pasture eliminating barnyard effect

Some options to help reduce barnyard effect –

Can you implement any of them?

make barnyard small enough that very little forage present lay down gravel, concrete, or herbicidesclose off access to barnyard during day and on full moon nights provide hay in barn at night when animals come in from pasture to cut down on night grazing in the barnyardreplace barnyards with narrow lanes from pastures to barnleave animals in rotated pastures 24 hours a day with portable shelter, water and feeders

“Zero” grazing

Sheep/goats raised in confinement or dry lot (with no grass) have fewer stomach worm problems.Sheep/goats put in confinement or dry lot do not usually get re-infected with stomach worms.Coccidiosis could be more of a problem in confinement.

One farm’s forage management strategy to control worms

hay feeding 30 Boer X breeding does from mid Dec through April. Herd kids in April and adult does wormed May1st.

rotational grazing of conventional pastures (6 acres) from May through July, goats stay on each area ~1 wk before rotating to next pasture – returned to each pasture in ~ 45 days. Horses follow 2 weeks after goats in most fields. Individual animals are wormed as needed. Entire herd wormed at end of July at weaning.

Management Strategy continued

month-long grazing of two brush pastures Aug through Sept (3 acres). Individuals wormed as needed. In 2006, entire herd fasted and wormed with 2 wormers for deer worm in October – wormers used are ones that barberpole worm already shows resistance to in herd

strip grazing of hay field regrowth from Oct until mid Dec (7 acres), animals moved to new strip every 5 to 9 days and never repeated on same strip. Individuals wormed as needed. Some years entire herd wormed Dec 15, some years entire herd wormed March 15th, some years neither worming necessary and only a few individuals wormed

Nutritional ManagementAnimals on a high plane of nutrition and in better body condition are better able to withstand worm burdens.

Nutrition in early pregnancy (fat stores) can affect the immune response to internal parasites.

Sheep receiving higher levels of protein prior to lambing have lower fecal egg counts.

Immune Response

Good nutrition stimulates immune systemCan select goats and sheep for low fecal egg counts Other diseases which depress immune system (e.g. coccidiosis, Johnes) can cause increased worm problems

Immune Response

When goat/sheep are lactating, immune system is suppressed and does not fight parasites. Arrested larvae acquired during the fall all mature simultaneously in the spring during lactation. Rationale for deworming before kidding. Protein consumption at 130% of daily requirements reduced flush of egg laying at parturition in sheep

Genetic Management

Try to select for “resistant” animals

“Resistant” BreedsSome sheep and goat breeds are more resistant to worms.

SheepGulf Coast NativeHair sheep

Barbados BlackbellySt. CroixKatahdinDorper (?)Royal White (?)

NOTTraditional wooled breeds

Goats Possibly –

Spanish/BrushMyotonic/TennesseePygmyKiko (?)

NOTBoer goatsDairy goatsAngora goatsSavanna????

“Resistant” IndividualsParasite resistance varies between individual animals of the same breed type.

20-30 percent of flock shed most of the parasite eggs.

Focusing deworming on susceptible animals will significantly reduce pasture contamination.

BUT - Lactation and weaning are examples of environmental effects that render an animal more worm-susceptible.

Culling worm-susceptible animals that have no environmental excuse for being “wormy” should increase flock resistance and reduce pasture contamination.

Drugs

A valuable, limited resource that must be managed properly.

Three drug families

1) Benzimidazoles Chemical name ends in

'..dazole Fenbendazole, Albendazole,

Oxybendazole

2) Nicotinics Levamisole, Morantel,

Pyrantel

3) Macrolides Avermectins

Ivermectin, Doramectin

Moxidectin

Benzimidazoles – “white drenches”

Fenbendazole – SafeGuard® or Panacur®Albendazole – Valbazen®Oxyfendazole – Synantic ®

Broad spectrumWide margin of safetyEffective against tapewormsValbazen

Effective against adult liver flukes.Should not be administered to pregnant animals.

Nicotinics

Levamisole - (clear drench). Tramisol ®, Levasole®, Prohibit®Morantel– Rumatel®, Positive Goat PelletPyrantel - Strongid®

RumatelOral feed additiveOnly effective against adult worms

PyrantelOnly effective against adult worms

LevamisoleBroad spectrumEffective against arrested larvaeNarrower margin of safety, especially injectable product

MacrolidesIvermectin –Ivomec®, Zimecterin ®, Eprinex ®, Promectin®Doramectin - Dectomax ®Moxidectin – Cydectin ®, Quest ®

Broad spectrumWide margin of safetyEffective against (biting) external parasites

MoxidectinNewest drugHas “Persistent activity”

Extra-label drug useOnly Fenbendazole (SafeGuard®) and Morantel (Rumatel®) are FDA-approved for goats.Only Albendazole (Valbazen ®), Ivomec ® drench, and Levamisole (drench and bolus) are FDA-approved for sheep.Use of a product that is different than its label constitutes extra-label drug use and requires a veterinary prescription in context of valid veterinarian-patient-client relationship.Should use exaggerated withdrawals when using drugs extra label (keep records). Check with http://www.farad.org/

Non-chemical dewormers – not yet!Botanical dewormers - herbsDiatomaceous earth (DE)No scientific studies have shown DE or other non-chemical treatments to reduce fecal egg countsMany natural “dewormers” would have to be given at toxic levels in order to be effectiveGarlic juice has shown promise?

OtherTannins, fungusCopper boluses (goats)vaccine

Epazote Study 1) Oil of Chenopodium administered in gel capsules at a rate of 0.15ml/kg body weight is ineffective in reducing the number or viability of internal parasite eggs in NY sheep and goats. Higher dose toxic to host animal.

A commercial organic worm discourager and a soluble soap, Basic H, were equally ineffective.

FAMACHA©

• Developed in South Africa in response to the emergence of severe anthelmintic resistance

• A system to assess Haemonchus contortis (barber pole worm) infection in sheep and goats and the need for deworming individual animals

• Named for its originator:

Dr. Francois “Faffa” MAlan CHArt

FAMACHA©• Reduces the number of

treatments by determining which animals to treat vs. treating whole flock.

• Reduces rate at which worms become resistant to drugs by increasing “refugia” – worms that are still susceptible to drug treatment.

• Identifies animals that need treatment most often and vice versa; thus offering the opportunity for genetic selection for parasite resistance assuming they have no environmental “excuse’.

FAMACHA©

Clinical Category

Eye Lid Color

Packed Cell

VolumeTreat?

1 Red > 28 No

2 Red-Pink 23-27 No

3 Pink 18-22 ?

4 Pink-White 13-17 Yes

5 White < 12 Yes

Treat adults at scores 4 and 5*Treat lambs and kids at

categories 3, 4, and 5

*South Africa recommends goats be treated at categories

3, 4, and 5

Precautions when using FAMACHA©• Only useful where Haemonchus

contortis is the primary parasite species.

• Cannot be used in a vacuum; other factors need to be considered when making treatment decisions.

• There are other causes of pale (e.g. liver fluke) or red (e.g. fever) eye lids

• Should be incorporated into an integrated parasite management (IPM) program that includes proper drug use, pasture rest and rotation, fecal egg counting, mixed species grazing, etc.)

How often should you check?

Must know if anthelmintic is effective.

FECRT

DrenchRite®

Always use card! Compare eye color to chart. Replace card after 12 months of use

Should only be used by properly trained individuals; improper use can lead to death of animals.

Precautions when using FAMACHA©

Other parasites of interest

LungwormsIndirect or direct life cycleSevere infestations cause coughing, fluid in lungs, pneumoniaTransmitted in feces Take fecal sample direct from animal (otherwise can confuse with soil nematodes)Same control program as stomach and intestinal worms.

TapewormsLife Cycle

Worms live in small intestines.Eggs pass out through feces.The egg is eaten by a pasture mite.The egg hatches.The mite is eaten by the sheep or goat.

Light loads of tapeworms tend not to be a problem, but severe infestations can cause problems.

Pasture mite

CoccidiaEimera sp. (species-specific)

Single-cell protozoa that damage lining of small intestines.

Can cause bloody diarrhea that may be smeared with mucousDamage can be permanent!

Prevent with good sanitation and proper stocking

Coccidiosis

Suspect when animals get diarrhea after 3 weeks of age“mucky butt” in lambsmany Eimeria species, host specific, variable pathogenicityimmunity to each species of coccidia develops with exposurewarmth and moisture permit sporulation

From Egg to infectious 1-2 days but easily survive 2-3 mo and can survive 1 year in optimum conditionsKilled by direct sunlight and low humidity (<25%)

Life Cycle of Eimeria spp.

Severe coccidiosis in goats/sheep causes many small white foci in the intestinal wall – absorption impaired

Fecal exams for coccidia

may have 10,000 or 100,000 per gram without diseaseEgg count drops only for a short time after treatment then rebounds none in older animal? You didn’t look!

Coccidiosis

raise dairy kids away from adultsIf possible, separate lambs and kids by age, ideally only a 2 weeks spread in age in a groupmilk is protective, weaning precipitates diarrheacoccidiostats in the milk and starter feed – decoquinate, monensin, lasalocid

Can use coccidiostats as additives in the feed, salt or water to help prevent:

Especially in pregnant females starting 1 month before parturition until weaning of their young. Continue in young animals after weaning.Lasalocid (Bovatec®)1,3

Monensin (Rumensin®)2,3

Dequinate (Deccox®)1,2

Amprolium (Corid®) in water1 - FDA-approved for sheep

2 - FDA-approved for goats3 - TOXIC to EQUINES!!!!!!

Sanitation – clean and dry

keep kids and lambs out of feeders !

Treatment of coccidiosis

oral sulfonamides –Sulmet, Albon, etc.amprolium 25-50 mg/kg per day for 5 days = 1 ml Corid 9.6% per 8 poundscan add to milk or directly drenchtreatment temporarily decreases shedding but does not eradicate parasite – rebound in oocyst countadequate selenium for immunity

Meningeal worm (deer, brain worm)Parelaphostrongylus tenuis

Parasite of White Tail Deer

Small ruminants are an abnormal host (sheep, goats, llama, alpaca)

Parasite has indirect life cycle – snails and slugs needed for infection

Larva travel from intestinal tract to spinal cord to brain, causing Nerve damage (can include lameness, gait abnormality, itching) can be as extreme as paralysis or even DEATH

Animals maintain appetite

Differential diagnosesCAE, OPPfracture, vertebral body abscesscopper deficiencytail docking infectionfoot rot, white muscle disease

listeriosisPolio-encephalomalaciabrain abscessrabiesscrapie

Treatment of P. tenuisin aberrant hosts

no controlled studiesescalation of drug dosagesivermectin 0.2 to 1.0 mg/kg for 1-5 dfenbendazole 10 to 50 mg/kg for 1-5 dusually both simultaneouslyanti-inflammatories important

corticosteroids if not pregnant: dexamethasone 0.1 mg/kg s.i.d. for 3-5 dflunixin 1 mg/kg s.i.d. or b.i.d. for 3 d

Prevention of exposure

do not pasture at edge of woods especially during wet seasonavoid low-lying poorly drained fields except under very dry conditionsfence off deer watering spotsuse fields deer prefer for hay, not grazingguardian dog may helptake advantage of hunting season!

Prophylaxis in aberrant host

for camelids, probably not for sheep and goats (Haemonchus resistance)injectable ivermectin q 4-6 wk pour-ons? (not sheep or goats)newer avermectins with longer duration?fenbendazoledaily pyrantel not effective

Liver flukesSome farms in NE US have acute or chronic liver fluke populationsRequires open water, snails (wet conditions)Can kill adult liver flukes with Albendazole (Valbazen®) or Ivomec® Plus)

Fasciola hepatica

common liver flukecycle includes fresh water snailsacute peritonitis (during migration)Often causes chronic problems afterwardshypoproteinemia, anemia (blood leaks into bile)

Clinical signs

Fascioloides magnaAmerican deer flukenatural parasite of deer and elksheep and goats abnormal hostslarval stages continue to migrate through liver - sheep and goats don’t excrete eggsACUTE disease - usually fatal within 6 months

liver of goat killed by fluke

Treatment of liver flukes

fence off wet areasalbendazole – 15 to 20 mg/kg, adult flukesclorsulon orally - adult Fasciola

3.5 mg/kg sheep, 7 mg/kg goats clorsulon orally – 8 wk Fasciola

7 mg/kg sheep, 15 mg/kg goatsclorsulon for Fascioloides – 21 mg/kg

QUESTIONS?