1

Fluke and WormInfections In

Cattle and Sheep

Fluke and WormInfections In

Cattle and SheepDouglas Gray

Veterinary ServicesAberdeen

2

Organic and Healthy!Organic and Healthy!

3

• 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

4

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?

5

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

6

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?

7

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)

8

Adult Liver Flukes(Fasciola hepatica)Adult Liver Flukes(Fasciola hepatica)

9

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

10

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

11

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

12

Mud snails : Intermediatehost of liver flukeMud snails : Intermediatehost of liver fluke

Untreated BolusTreated

13

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

14

• 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

16

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

17

Acute Liver Fluke : SheepAcute Liver Fluke : Sheep

Untreated BolusTreated

Immature (4-6 week) flukes

Affected ovine liver

18

Adult flukes

Chronic Liver Fluke: Sheep

Bottle jaw

19

Liver Fluke Disease inCattleLiver Fluke Disease inCattle

Untreated BolusTreated

Tracts ofmigratingimmatureflukes

20

Black Disease:Infectious Necrotic HepatitisBlack Disease:Infectious Necrotic Hepatitis

BolusTreated

Affected area

Clostridium novyi (oedematiens)

21

Fluke Control StrategiesFluke Control Strategies

• Drainage to reducesnail habitats

• Fence wettest parts offarm and graze at lowrisk periods

• Strategic treatments• Monitor for fluke

22

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?

23

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

24

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!

25

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

26

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

27

Worms: Safe from harm!Worms: Safe from harm!

28

Roundworm diseases in sheepand cattleRoundworm diseases in sheepand cattle• Parasitic gastroenteritis(PGE)

• Scour and ill thrift– Ostertagia– Trichostrongylus– Cooperia

• Nematodirus• Haemonchus• Lungworms

29

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

30

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?

31

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)

32

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)

33

Have A StrategyHave A Strategy

• Work out a controlstrategy for yourfarm

• Develop a costeffective, reliableand sustainable plan

34

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

35

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

36

Worming Ewes Pre-tuppingWorming Ewes Pre-tupping

• No routine drenchingof fit adult ewes pre-tupping

• Drench immature orlean ewes only

• Use FECs?

LSSC

37

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

38

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

39

Collection of Dung Samples 1Collection of Dung Samples 1

• Hold mob of sheep in corner of field

40

Collection of Dung Samples 2Collection of Dung Samples 2

• Allow sheep to move after ten minutes

41

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

42

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

43

Examples of bioactive foragesExamples of bioactive forages

44

Ewe Grazing Chicory SwardEwe Grazing Chicory Sward

45

Effect of chicory on worm egg output (FEC) inlambs grazing a pure sward

46

47