Treatment and Control Programs for Ruminant Parasites

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Treatment and Control Programs for Ruminant
Parasites
2
Traditional Louisiana Cow-Calf Treatment
Time
Nematodes Flukes CALVES

Pre-weaning
/- (heavy calves) -
Weaning (Oct-Nov)
Feb-Mar

- RETAINED HEIFERS, STOCKERS
Spring
/-
Fall
1st and 2nd CALF
BROOD STOCK
Spring
/- Fall

MATURE gt3-4 YEAR
Spring
Dependent on /-
Fall Herd History

3
Safe Pasture Treat and Move

• Rotate growing stock (and older stock if
  possible) to safe minimally infected pastures 1-3
  days after treatment
• Rest pastures in hot, dry summer-fall for 50-75
  days (larvae are killed by heat and dryness)
• Graze pastures by dry, pregnant cows (very low
  egg shedding rates)
• 3. Overseed cropland with ryegrass or wheat
  that has not been recently used by cattle (eg
  soybeans at defoliation, rice stubble, hay
  fields)

4
Treatment Decisions

• Age/Class (Cow-Calf Stocker, Feedlot)
• Seasonal dynamics of major species present
• Spectrum of drug vs major species present
• Drug delivery systems (drench, paste, injectable,
  pour-on, pasture self treatment blocks, pre-mix,
  top-dress, bolus)
• Cost-Effectiveness (Room to improve body
  condition score Monitor herd fecal egg count to
  estimate parasite burdens)
• NO BLANKET RECOMMENDATIONS. Modify based on
  principles and guidelines. Major variation
  between herds.

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Low Input commercial cow-calf operation
Herd body condition scores of 3-4 in late winter
mean low productivity, room to improve and
likely benefit of parasite control programs
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December calf with nutritionally stressed mother
in March Body condition scores of 4 or below
indicate anestrus and poor mothering ability.
Light calves and prolonged calving interval
result.
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Seasonal transmission patterns
Strategic Control is usually directed against
Ostertagia
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Strategic control program for Coastal LA Direct
at the period that maximum nutritional stress,
maximum Ostertagia burdens and maximum fluke
burdens all coincide (Liebigs law of the
minimum)
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Parasite Herd Monitoring Mailer Kit
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Herd Parasite Monitoring

• Use LAVMDL or similar mailer pouch kits. If
  squeeze all air out of small plastic baggies,
  nematodes do not develop during shipping or
  transport. Refrigerate until examine.
• Sample herds based on local epidemiological
  pattern so that examine feces at time of maximum
  egg shedding by adult worms (GI nematodes winter,
  flukes fall)
• Ten random samples per rectum or fresh from
  pasture. Do quantitative sugar flotation, report
  as mean EPG and prevalence (or mean count if
  composite samples)
• McMaster chamber counts OK, but misses lungworms,
  coccidia, low egg counts.
• Use Flukefinder for Fasciola EP2G counts.

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Winter Wormtest (EPG)
Risk Cows Growing
Stock Low lt5
lt50 Moderate 5-25
50-250 High 25-50
250-500 Economic gt50
gt500 If good control
program, lt1EPG and lt 25 prevalence is attainable
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Fall Fluketest EP2G on cow herd
Risk Prevalence Mean
EP2G Low lt25
lt1 Moderate 25-75
1-3 High 75-90
3-10 Economic gt90
gt10 gt40 flukes at necropsy is economic
level gt200 flukes clinical
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Anthelminthic Classes
Benzimidazoles (Microtubules) FBZ Broad
spectrum drench, paste, feed through, dairy OK
ABZ Broad spectrum flukicide
OxBZ Rumen
injection, paste
TBZ Oldest, seldom used, no L4
efficacy Avermectins/Milbemycins
(GABA inhibition) - long acting endecticides
Ivermectin - Injectable /- clorsulon Pour-on
Bolus Eprinomectin - Pour-on, zero withdrawal
time, dairy OK
Moxidectin - Pour-on,
zero withdrawal time, dairy OK Doromectin -
Pour-on, Injectable Benzenesulfonamides
(Glycolysis) Clorsulon flukes only
Imidazoles (Acetocholine receptor)- Levamisole
No L4 effect
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Control Program Scenario Compare improved
parasite control and potential cost-benefit of a
mid-summer/mid-winter treatment (1 arrow) with
traditional fall/-spring treatment of cows and
growing stock (2 arrow). Evaluate principles
and guidelines of parasite control and the unique
herd situation to make individual herd decisions.
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Stocker Calves
The south produces mainly light calves that
graze on winter pasture as stockers, then go to
feedlot at 800 lb
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Feedlot Calves
Most calves are treated for nematodes and
ectoparasites at receipt. Flukicide and coccidia
prevention given if history indicates
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Ruminant Internal Parasite Checklist
Primary 90
Secondary, Unusual, Minor 10
Ostertagia
Strongyloides
Chabertia Haemonchus
Trichuris
Capillaria Oesphagostomum
Muellerius
Neoascaris Trichostrongylus
Toxoplasma
Protostrongylus Cooperia
Fascioloides
Dicrocoelium Nematodirus
Paramphistomum
Thysanosoma Bunostomum
Giardia
Thelazia Dictyocaulus
Stephanofilaria Fasciola hepatica
Eleophora Eimeria
Seteria Neospora
Sarcocystis Tritrichomonas
Fasciola gigantica Cryptosporidium
Zoonotic importance - consider to be primary
group