Post on 09-May-2018
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Fluke and WormInfections In
Cattle and Sheep
Fluke and WormInfections In
Cattle and SheepDouglas Gray
Veterinary ServicesAberdeen
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• What do the standards say?• Losses from fluke and worms• Practical ways to prevent losses• Control of liver fluke• Control of worms• Keeping an eye on things
Summary of Topics
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Animal Health: The OrganicStandardsAnimal Health: The OrganicStandards• Certification Bodies are responsible for standards
POSITIVE HEALTH to be achieved by PREVENTION:
- Selection of appropriate breeds- Preventive husbandry strategies- High quality feed, exercise and access to pasture- Appropriate stocking densities
In addition, some certification bodies require farmers to produce ananimal health plan to detail how good animal health and welfare will beachieved.
How can the standards be put into practice on individual farms?
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Preventive HusbandryPreventive Husbandry
• Disease prevention using biologicalknowledge rather than medicines
• Whole farm system approach• Applicable to parasite disease?
How?: Disease prevention strategiesIncreasing animal immunityOptimising nutritionGood stockmanship
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Disease Prevention StrategiesDisease Prevention Strategies
Prevent Entry: Closed herds/flocksQuarantine treatmentsControl of wildlife carriers
Reduce Exposure: Reduce stocking densityGrazing managementReduce worm egg output
Treat to remove worms
Encourage Immunity: Control exposureImprove NutritionVaccines?
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Medicine Use On Organic Farms
• Sick animals MUST be treated
• Medicines must be authorised for the species– Herbal/Homeopathic/Trace Elementsto be used in preference - IF EFFECTIVE
Veterinary medicines - Veterinary role Therapeutic Strategic
• Vaccines - where there is a known disease risk
• Not permitted - Ivermectins Monepantel
• Records and withdrawal periods
• “Four strikes and you’re out” (Not wormers)
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Liver Fluke InfectionsLiver Fluke Infections
• What effects do they have?• Liver fluke life cycle• Factors affecting life cycle• Understanding the disease• Treatment and control options• Diagnosis and monitoring
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Liver Fluke - Losses/CostsLiver Fluke - Losses/Costs
• Deaths due to acute fluke (Sheep)• Ill Thrift/Deaths due to sub-acute fluke (Sheep)• Ill Thrift/Loss of productivity due to chronic
fluke (Cattle/Sheep)• Liver condemnations• Costs of prevention/treatment• Costs of related disease
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Liver fluke life cycle:Minimum duration 4-5 MonthsLiver fluke life cycle:Minimum duration 4-5 Months
6-8 weeksdevelopmentin snail
Prepatent period10-12 weeks
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Mud snails : Intermediatehost of liver flukeMud snails : Intermediatehost of liver fluke
Untreated BolusTreated
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Liver Fluke Life Cycle - FeaturesLiver Fluke Life Cycle - Features
• Availability of intermediate host (snails)• Availability of mammalian hosts- Sheep
- Cattle- Deer- Rabbits
• Effect of climate - Temperature : >10oC- Rainfall (summer)
• Suitable snail habitats - Mud• Mammalian host immunity
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• Acute/Subacute Disease- 0-8 weeks after infection- Immature fluke migration, direct liver damage,
internal bleeding - death• Chronic Disease
- More than 8 weeks after infection- Adults migrate up bile ducts, feeding causes
anaemia, chronic liver damage
Liver Fluke DiseaseLiver Fluke Disease
15June
Understanding Acute andChronic Fluke Disease
Increase ineggs onpasture
December
Increase inmetacercariaon grass
Acute Flukedisease Chronic Fluke
disease
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Clinical SignsClinical Signs
Cattle SheepAcute Rare Sudden Death
AnaemiaAbdominal Pain
Sub-Acute Possible Ill Thriftin Calves Lethargy
Poor FleecesAnaemia
Chronic Loss of Loss of ConditionCondition Emaciation
Bottle JawAnaemia
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Acute Liver Fluke : SheepAcute Liver Fluke : Sheep
Untreated BolusTreated
Immature (4-6 week) flukes
Affected ovine liver
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Liver Fluke Disease inCattleLiver Fluke Disease inCattle
Untreated BolusTreated
Tracts ofmigratingimmatureflukes
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Black Disease:Infectious Necrotic HepatitisBlack Disease:Infectious Necrotic Hepatitis
BolusTreated
Affected area
Clostridium novyi (oedematiens)
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Fluke Control StrategiesFluke Control Strategies
• Drainage to reducesnail habitats
• Fence wettest parts offarm and graze at lowrisk periods
• Strategic treatments• Monitor for fluke
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Fluke Treatments : OrganicAspectsFluke Treatments : OrganicAspects
• Evidence of infection?• When to treat and with which drug?• Acute: Immature flukes in Autumn• Chronic: Adult flukes in winter• Combined fluke and wormer?• Resistance problems• Extended withdrawal periods• Build into Animal Health Plan?
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Flukicides for cattle and sheepFlukicides for cattle and sheep
• Fasinex/Tribex (Triclabendazole)#:Kills fluke from 2 days old (sheep), 2 weeks (cattle)
• Flukiver (Closantel)#: Sheep3-4 week old flukes: 23% to 73% effective5 week old flukes: 91% effective6-8 week old flukes: 91% to 95% effectiveAdult flukes: 97% to 100% effective
• Trodax (Nitroxynil): Adult and immature flukes
• Valbazen (Albendazole): Sheep Adults only# Effective against immature flukes
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Treating To Control Liver FlukeDiseaseTreating To Control Liver FlukeDisease
THE SUMMER DOSE LIMITS EGGSON PASTURE
June
Increase ineggs onpasture
December
Increase“Cysts”onGrass
Acutedisease Chronic
disease
Understanding Acute & ChronicFascioliasis
THE WINTERDOSEKILL ADULTS
THE AUTUMN DOSEKILL YOUNG FLUKE
Consult your vet about themost appropriate drug FOR
YOUR FARM!
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Aims of Seasonal Fluke TreatmentsAims of Seasonal Fluke Treatments
• Autumn - To stop immature fluke migration, preventliver damage, clinical disease (black disease), andimprove ewe condition for pregnancy
• Winter - To kill adult flukes in the bile ducts andprevent liver/biliary damage and ill-thrift/anaemia duringthe winter
• Spring - To prevent eggs being laid on pasture whichcould infect snails in summer
• Summer - To prevent infection of snails and break thecycle of infection
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Diagnosis and Monitoring ofFluke InfectionsDiagnosis and Monitoring ofFluke Infections
• Use of regular faecal fluke egg counts
• Use in cattle and sheep
• Can be done on bulked faeces sample
• At same time as faecal worm egg counts
• When to do it?• Cattle: At housing or turnout?• Sheep
– At winter gather (at scanning time)?– At marking gather?
Fluke egg
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Roundworm diseases in sheepand cattleRoundworm diseases in sheepand cattle• Parasitic gastroenteritis(PGE)
• Scour and ill thrift– Ostertagia– Trichostrongylus– Cooperia
• Nematodirus• Haemonchus• Lungworms
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Direct Life Cycle of Worms CausingPGEDirect Life Cycle of Worms CausingPGE
Sheep/Cattle Adult Worms in:
Immatureworms Abomasum : Ostertagia
HaemonchusIntestine : Trichostrongylus
Nematodirus
Larvae onPasture Eggs in
FaecesL3
Prepatent Period: Three weeks
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Control of Worm ParasitesControl of Worm Parasites
Grazing Management: Clean grazingAlternate grazingMixed grazingReduced stocking ratesUse of immune animalsStrategic moves
Nutritional Factors: Trace elementsMetabolisable proteinBioactive forages
Immune status: Genetic Selection (FEC)
Wormers?
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Wormers on Organic FarmsWormers on Organic Farms
• Cannot be used routinely• Use to treat scouring animals• Limitations on wormer groups• Can use strategically if needed
(eg lambing ewes)• Avoid development of AR
(SCOPS guidelines)
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Four Groups of WormersFour Groups of Wormers
Broad spectrumwormers
Group 1 (BZ)Benzimidazoles
(White drenches)
Group 2 (LV)Levamisol
(Yellow wormers)
Group 3 (ML)Ivermectin etc.
(Clear wormers)
Group 4 (AD)Monepantel
(Orange drench)
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Have A StrategyHave A Strategy
• Work out a controlstrategy for yourfarm
• Develop a costeffective, reliableand sustainable plan
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Treat Sheep in QuarantineTreat Sheep in Quarantine
• Apply to all introducedsheep and goats
• Treat with an ML andan LV sequentially
• Hold off pasture (yard)for 24-48 hours
• Turn out on to dirty(contaminated) pasture
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Worm Only if NecessaryWorm Only if Necessary
• Lambs- treat only when
necessary- extended intervals
between dosing• Ewes at tupping• Ewes at lambing• Use of faecal egg
counts (FECs)
LSSC Ltd
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Worming Ewes Pre-tuppingWorming Ewes Pre-tupping
• No routine drenchingof fit adult ewes pre-tupping
• Drench immature orlean ewes only
• Use FECs?
LSSC
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Worming Ewes at LambingWorming Ewes at Lambing
• Strategic use toreduce egg output?
• Fit ewes and thoserearing singles do nothave raised worm eggoutputs
• A high protein rationalso reduces eggoutput in twin bearingewes
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Faecal Egg Counts (FECs)Faecal Egg Counts (FECs)
• FECs can give a useful guide to the wormburden in a group of sheep
• At least 10 animals should be sampled pergroup
• A “group” is a mob of sheep of the same sex,age, reproductive status and treatment history,grazing the same field
• The faeces from 10 sheep may be pooled(bulked), but only at the laboratory
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Collection of Dung Samples 3Collection of Dung Samples 3
• Collect ten fresh samplesinto individual pots orbags
• Use gloves• Store samples in cool
place• Post samples as soon as
possible or deliver toyour vet or lab
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WORMSCANWORMSCAN
• A farmer sampling kit forcollecting 10 samples
• Approved packaging andpre-paid postage
• Results to vet & farmer• Used to monitor fluke
and worm• Used to check wormer
efficacy