3. Incidence: affected 29% of cattle
entering eight principal abattoirs in
Scotland during January and February
2004
◦ Sept - Dec 2002 : 65%
Cost: 10 - 15% per finished animal
4. Global warming
◦ warmer
◦ wetter
Recession in agriculture
Farms dose sheep but not cattle
Reduction in veterinary input on farms
◦ will health planning reverse this?
5. Liver Fluke (Fasciola hepatica) : Life Cycle
Minimum duration 4-5 months
6-8 weeks development in snail
Prepatent period 10-12 weeks
7. Availability of snail habitats
Moisture (Summer rainfall: May - Oct)
Temperature
◦ <10 degrees C - no development
◦ >15 degrees C - significant development
Summer infection of snails
◦ leads to build up of infective stage on pasture in theleads to build up of infective stage on pasture in the
autumnautumn
Immunity (cattle)
8. Metabolic disease in
dairy cows
recumbency / milk
fever/staggers
◦ not associated
with calving
Chronic Disease
(Jan - March)
◦ 8 weeks + after infection
◦ adults migrate up bile ducts,
chronic liver damage,
◦ reduced growth
◦ condition loss
◦ milk production/quality
deteriorates
◦ severe cases: anaemia,
oedema (bottle jaw)
10. Faeces for fluke eggs
◦ detects mature adults only
Abattoir returns
blood samples for liver damage
◦ non-specific
Post mortem examination
11. Autumn (Sept-Nov)
To stop immature fluke
migration
◦ prevent liver damage &
clinical disease
Spring & Summer (April-June)
– To prevent eggs being laid on
pasture which could infect snails in
summer
Winter (Dec - March)
To kill adult flukes in
the bile ducts
– prevent liver damage
and ill-thrift during the
winter
!
12. Current:
◦ crude estimates of risk based on diagnostic data
(SAC) and weather data
◦ published in farming press, Novartis ‘fluke monitor’
etc
The Ideal:
◦ funding for scientific analysis of meteorological data
and snail surveys to give accurate forecast
13. Beef Cattle/Dairy Youngstock
◦ Inwintered :
Low Risk : Treat Jan
High Risk: Treat Oct (2 weeks post housing) & Jan
Outwintered
Low Risk : Treat Jan, May & Oct
High Risk: Treat Jan, May, July & Oct
Dairy Cows:
◦ ALL licensed product for lactating cows have
milk withdrawal requirement
preventative treatment at dry-off
Advice will vary annually and from farm to farm
14. Triclabendazole: 2 day old immatures to adults -
broadest spectrum product
But
◦ ! Triclabendazole resistant flukes starting toTriclabendazole resistant flukes starting to
appear!appear!
Closantel : 4 week old immatures to adults
Nitroxynil: 6 week old immatures to adults
Oxyclozanide, Netobimin & Albendazole: Adults
only
15. Triclabendazole resistant flukes reported in Eire,
Scotland (Argyll) and Wales IN SHEEP
Continuing clinical signs following treatment
Faeces samples for fluke eggs to check for possible
resistance
◦ 3-6 weeks after treatment
16. Assess degree of problem
◦ midwinter sampling of cattle and sheep
◦ abattoir data
Examine control options
◦ grazing, fencing, drainage, dosing
National forecast
Establish strategic dosing/grazing plan
◦ review effectiveness annually
Correct choice of flukicide
◦ for time of year
◦ be aware of possible anthelmintic resistance
test faeces 3 weeks post dosing
17. Route
of
admin.
Age of
flukes
when
efficacy
90-100%
(weeks)
Meat /milk
withdrawal
(days)
Effective
against
nematodes
comment
Triclabendazole oral 2 56 no
Nitroxynil s/c inj 9 60 no Stains operator
Clorsulon s/c inj 11 35 yes Only avalable with ivermectin thus
includes efficacy against
ectoparasites
Albendazole oral 14 14 yes Fluke dose higher than worm dose
leading to potential for confusion.
Netobimin oral 11 10 yes Cannot use in 1
st
7 weeks of
pregnancy. Fluke dose higher than
worm dose leading to potential for
confusion.
Oxyclozanide oral 14 28 yes Only available with levamisole
