1. Sustainable Integrated
Parasite Management
(sIPM) in Small Ruminants
SUSAN SCHOENIAN
Sheep & Goat Specialist
University of Maryland Extension
sschoen@umd.edu – sheepandgoat.com
sheep101.info - wormx.info
2. American Consortium for Small Ruminant
Parasite Control (ACSRPC)
Southern Consortium for Small Ruminant
Parasite Control (SCSRPC) was formed in
2003 in response to the critical state of the
small ruminant industry associated with the
emergence of anthelmintic-resistant worms.
As membership expanded, the name was
changed to the American Consortium for
Small Ruminant Parasite Control (ACSRPC).
The ACSRPC is a group of scientists, veterinarians, and extension specialists devoted to:
1) Developing novel methods for sustainable control of gastro-intestinal nematodes in small ruminants.
2) Educating stakeholders in the small ruminant industry on the most up-to-date methods and recommendations
for control of gastrointestinal nematodes.
South Africa 2015
5. Gastro-intestinal parasites in small ruminants
Primary health problem affecting small ruminants in
warm, moist climates, especially during periods of
summer rainfall.
There are many reasons why sheep and especially
goats are more susceptible to internal parasitism
than other farm livestock.
Worms have developed resistance to all dewormers
and dewormer “chemical” classes.
Few dewormers are FDA-approved for goats. No
combination dewormers are available in US and no
new dewormers have been introduced in 20 years.
6. All small ruminants have parasites. It is normal!
However, risk of clinical parasitism varies.
ANIMAL DIFFERENCES
Species
Breed
Genetics
Age
Reproductive status
ENVIRONMENTAL EFFECTS
Geography
Climate
Nutrition
Production practices
7. Effects of age, production status, and plane
of nutrition on immunity (to parasites)
Source:
Understanding the Risk
Factors by Dr. Richard
Ehrhardt, ACSRPC,
http://www.wormx.info/ris
kfactors
9. Sheep and goats can be infected simultaneously
with many different kinds of internal parasites.
MULTI-CELLULAR (HELMINTHS)
1) Nematodes
Roundworms
Strongyles
2) Cestodes
Flatworms
Tapeworms
3) Trematodes
Flukes
SINGLE CELL PROTOZOA
1) Coccidia
2) Giardia
3) Cryptospordia
11. Nematodes of primary importance
1) Haemonchus contortus
Barber Pole Worm
2) Trichostrongylus spp.
Black scour worm (bankrupt worm)
3) Teladorsagia (formerly Ostertagia)
Brown stomach worm
Eggs look the same. You need to hatch the eggs to differentiate species from larvae stage. 2
& 3 are often not differentiated even when doing larvae ID.
Strongyle
eggs
12. Life cycle of roundworms
Short and direct with no intermediate host
L3
L2 L1
L4, adult
13. Clinical signs of infection with strongyles
BARBER POLE WORM
Anemia
Blood and protein loss
Low packed cell volume (PCV)
“Bottle jaw”
Sub-mandibular edema
Swelling directly under jaw
Loss of weight and body condition
Diarrhea (scours)
Weakness
Anorexia
Death
Acute haemonchosis can cause sudden death.
TRICHOSTRONGYLES/TELADORSAGIA
Hypersensitivity of gut
Damage and inflammation of gut
Diarrhea (scours)
Loss of weight and condition
Slow growth
Lethargy
Death (sometimes)
Effects are usually additive due to lower
pathogenicity and mixed infections with H.
contortus.
15. Meningeal worm
(Parelaphostrongylus tenuis)
Parasite of white tail deer
(non-pathogenic in deer)
Sheep, goats, and camelids are
abnormal, aberrant hosts for parasite.
Parasite has indirect life cycle: snail or slug
required as intermediate host.
Small ruminants get infected when they
consume snail, slug, or slime stream
(on vegetation) containing L3 (larvae).
Larvae travel from intestinal tract
to spinal cord to brain, causing nerve damage
and inflammation.
16. Meningeal worm
(Parelaphostrongylus tenuis)
No definitive diagnostic in live animal
Diagnosis is usually based on clinical signs and history.
Parasite is difficult to locate in necropsy.
Symptoms: lameness, hind end weakness, gait abnormality,
constant itching, paralysis (extreme)
and death (rare).
Animals typically maintain appetite.
No proven or FDA-approved treatment.
Cornell University has been evaluating treatment protocols
and potential for vaccine.
Cornell University image
17. Treatment protocol for meningeal worm (ELDU, Rx)
Cornell University (14 farms: 38 goats and sheep)
Not pregnant Late Gestation
Fenbendazole (SafeGuard®)
25 mg/kg orally for five days (1 1/3 cc/10 lbs.
[Meat WD: 28 d, goats; 80 d, sheep]
Dexamethasone
0.2 mg/kg IM for first 3 days (½ cc/10 lbs.)
0.1 mg/kg IM for next 2 days (¼ cc/10 lbs.)
Banamine
1.1 mg/kg orally for 5 days
(1 cc/100 lbs.)
Treatment A Treatment B
Ivermectin 1% injectable
0.5 mg /kg SQ for 5 days (¼/10 lbs.)
[Meat WD: 96 d, sheep and goat]
Ivermectin placebo
¼ cc/10 lbs. SQ for 5 days
https://nydairyadmin.cce.cornell.edu/uploads/doc_392.pdf
It is not known if
ivermectin
improves
outcome;
however, it
increases meat
withdrawal to 96
days.
Theoretically,
ivermectin
cannot pass
through the
blood-brain
barrier.
18. Tapeworms (Moniezia expansa)
Diagnosed by seeing segments in feces or passage of
worm.
Only worm that is visible in feces or outside of animal.
Parasite has indirect life cycle; pasture (grass) mite
serves as intermediate host.
Tend to be non-pathogenic;
immunity develops at an early age.
Almost all research (in sheep) shows no benefit to
treating for tapeworms.
19. Tapeworms (Moniezia expansa)
Heavy infestations
1) Mild unthriftiness and GI disturbances
2) Intestinal blockages (rare)
3) Can alter intestinal function and affect gut motility, causing
predisposition to enterotoxemia (occasional).
Treatment
1) SafeGuard® (2x dose, Rx)
2) Valbazen® (Rx, goats)
3) Praziquantel [Rx] via Quest Plus®, Equimax®, or Zimecterin
Gold® (or combo drugs from other countries)
Sheep and goats can be intermediate hosts for tapeworms
that infect dogs. Called sheep measles (causes cysts in
meat).
Intestinal blockage
20. Coccidia (Eimeria spp.)
Single cell protozoa
Host-specific
Not all Eimeria spp. are
pathogenic
Direct life cycle, but more
complex than stomach worms.
Other major parasite concern in
small ruminants.
21. Coccidiosis
Most commonly seen in lambs and kids just before weaning.
Most commonly observed in intensively-managed operations,
but outbreaks can occur in pasture-rearing environments.
Most commonly associated with poor hygiene, wet conditions,
overcrowding, and stress.
Sheep develop strong and lifelong immunity; coccidiosis is
rare in adult sheep.
Goats don’t develop as strong immunity; coccidiosis can
occur in goats of any age.
Adults harbor small numbers of coccidia and are source of
infection for their offspring.
22. Signs of clinical coccidiosis
Sub-clinical coccidiosis may be more costly.
Diarrhea (scours) – not always
Brown, liquid, foul-smelling
Sometimes containing blood or mucous
Dirty hocks, tail
Hollow flanks, hunched up appearance
Open fleece
Depressed
Anorexia
Dehydration
Anemia
Death (some cases)
Fecal oocyst counts are not overly reliable as a diagnostic
tool.
Animals that recover may experience more subtle
and long-lasting effects.
23. Prevention of coccidiosis
COCCIDIOSTATS (IONOPHORES)
ANTI-COCCIDIA DRUGS
Feed or mineral
1) Bovatec® (sheep, Rx goats)
Lasalocid sodium
2) Rumensin® (goats, Rx sheep)
Monensin
3) Deccox® (sheep, goats)
Decoquinate
Water
1) Corid® (Rx, OTC)
Amprolium
NATURAL
Prevention starts with good hygiene,
management, and nutrition.
Sericea lespedeza pellets
Oregano oil (?)
Rumensin® is toxic to equines. Bovatec® and Deccox® should not be fed to equines.
24. Treatment of coccidiosis
1) Corid® (Rx, OTC)
Amprolium
2) Sulfa drugs (Rx)
a) Sulmet®
Sulfamethazine
b) Sulfadimethoxine
Di-methox®
As part of the new Veterinary
Feed Directive (VFD), water
soluble antibiotics transitioned
from OTC to Rx. You need to
get from veterinarian.
Though rare, treatment with
amprolium may cause
polioencephalomalacia
(thiamine deficiency)
26. There are three “chemical” classes of dewormers.
There is cross resistance with drugs in same class.
GROUP 1
Benzimidazoles
(BZ)
GROUP 2
Macrocylic lactones (ML)
GROUP 3
Nicotinic agonists
Avermectins Milbemycins Imidazothiazoles Tetrahydropyrimidines
Fenbendazole
SafeGuard®
Ivermectin
Ivomec®
Moxidectin
Cydectin®
Quest®
Levamisole
Prohibit®
Leva-Med®
Tramisol®
Levasol®
Morantel
Rumatel®
Albendazole
Valbazen®
Doramectin
Dectomax® Pyrantel
Strongid®
Oxfendazole
Synanthic®
Eprinomectin
Eprinex®
27. Anthelmintics FDA-approved for sheep
1
Benzimidazoles
Albendazole
Valbazen®
2a
Avermectins
Ivermectin
Ivomec® sheep drench
2b
Milbimycins
Moxidectin
Cydectin® sheep drench
3
Levamisole
Prohibit® Leva-Med®
Adult worms X X X X
Larvae (L4) X X X Limited
Hypobiotic larvae X X X Limited
Lungworms X X X X
Tapeworms X
Liver flukes Adult stage
Coccidia
External parasites
Some
labeled for bot control
Some
Not labeled
Persistent activity X X
Safety
10x
pregnancy restriction
20x 5x 3x
Dosage 3 ml/100 lbs. 3 ml/26 lbs. 1 ml/11 lbs. Depends on dilution
Meat withdrawal 7 days 11 days 7 days 3 days
28. Anthelmintics FDA-approved for goats
1
Benzimidazoles
3b
Morantel
Fenbendazole
SafeGuard®
Albendazole
Valbazen®
Feed premix
Rumatel
Adult worms X Not approved X
Larvae (L4) X Not approved sporadic
Hypobiotic larvae X Not approved
Lungworms X Not approved
Tapeworms X Not approved
Liver flukes Adult stage
Coccidia
External parasites
Persistent activity
Safety wide 10x (sheep)
pregnancy restriction
~20x (sheep)
Dosage 1.2 ml/50 lbs. 4 ml/100 lbs. Varies by product
Meat withdrawal 6 days 7 days 30 days
Milk withdrawal 0 days
29. Extra-label anthelmintics for goats
1
Benzimidazoles
2a
Avermectins
Ivomec®
sheep drench
2b
Milbimycins
Moxidectin
Cydectin® sheep drench
3a
Levamisole
Prohibit®
Leva-Med®
Fenbendazole
SafeGuard®
Albendazole
Valbazen®
Adult worms X X X X X
Larvae (L4) X X X X Limited
Hypobiotic larvae X X X X Limited
Lungworms X X X X X
Tapeworms X X
Liver flukes Adult stage
Coccidia
External parasites Some
label for bot control
Some
Not labeled
Persistent activity X X
Safety wide 10x
pregnancy
restriction
20x 5x 3x
Dosage 1.1 ml/25 lbs. 2 ml/25 lbs. 6 ml/25 lbs. 4.5 ml/25 lbs. Depends on
dilution
Meat withdrawal 16 days
(1 day for each additional day used)
9 days 14 days 17 days 4 days
Milk withdrawal 4 days
(1 day for each additional day used)
7 days 9 days 8 days 3 days
30. Coccidiostats and anti-coccidia drugs
Tradename Ingredient FDA approval Administration Dosage Withdrawal Prevention Treatment
Bovatec® Lasolocid sodium Sheep, confinement
Feed
Mineral
30 g/ton feed 0 days X
Rumensin® Monensin Goats, confinement
Feed
Mineral
15 g/ton feed
(sheep)
20 g/ton feed (goats)
0 days X
Deccox® Decoquinate
Sheep and goats,
young, not lactating
Feed
Mineral
22.7 mg/100 lbs. of
BW per day
Varies by product
0 days X
Corid® Amprolium ELDU, OTC
Feed additive
Drinking water
Oral drench
Not labeled 2 days X X
DiMethox® Sulfadimethoxine ELDU, Rx
Drinking water
Oral drench
Not labeled NA X
Sulmet® Sulfamethazine ELDU
Drinking water
Oral drench
Not labeled NA X
Vecoxin Diclazuril NA Oral drench
1 ml/5.5 lbs.
Single
administration
0 X X
32. Anthelmintic resistance
Worms have varying degrees of resistance to all dewormers
and dewormer “chemical” classes.
Resistance varies by geographic region and farm and is
based on past deworming and management practices.
Resistance worms pass their resistant genes onto the next
generation of worms.
Resistance is different with levamisole; it is homozygous
recessive.
Resistance is/was inevitable; no treatment will kill 100% of
worms.
Resistance is defined as failure to reduce fecal egg county
by 95% or more.
As resistance increases, treatment becomes less effective;
at 50% resistance, drug is no longer effective as sole
treatment.
33. Two ways to test for anthelmintic resistance
FECAL EGG COUNT
REDUCTION TEST (FECRT)
“Gold Standard” for determining dewormer
resistance.
Old protocol
Compare post-treatment fecal egg counts to
untreated group (controls)
New protocol
Compare pre- and post-treatment fecal egg counts.
Need 15 animals per group
Need minimum egg counts.
Labor intensive. Cost varies.
Results: % fecal egg count reduction (FECR)
DRENCHRITE®
LARVAL DEVELOPMENT ASSAY (LDA)
Labor-intensive in-vitro test that determines
resistance to all dewormers simultaneously from a
single pooled fecal sample.
Sample 10-15 animals.
Minimum FEC of 500 epg
Includes larvae ID
$450 per sample
Dr. Ray Kaplan’s lab at University of Georgia is only
US lab that does test.
Results: Susceptible, Suspected Resistance, and
Resistant (<95% FECR)
34. Determining anthelmintic resistance on
sheep farms in the southeastern US
Objective:
Determine anthelmintic (dewormer) resistance on 30
commercial sheep farms (mostly 100+ ewes) in
Maryland, Virginia, and Georgia.
Project funded by ASI’s Let’s Grow Program.
1) University of Maryland (1-10)
2) Virginia State University (11-16)
3) Fort Valley State University (17-26)
Cost-share DrenchRite® test (larval development
assay; $450) to determine anthelmintic resistance.
Tests conducted by University of Georgia College of
Veterinary Medicine (Dr. Ray Kaplan’s lab).
35. Percent farms with anthelmintic resistance
Less than 95% FECR
0
10
20
30
40
50
60
70
80
90
100
Benzimidazoles Ivermectin Levamisole Moxidectin
Maryland Virginia Georgia
37. Levels of resistance to benzimidazoles
Number of farms (n=26)
0
5
10
15
20
25
30
Susceptible Suspected resistance Low to moderate
resistance
Moderate to high
resistance
Full resistance
Georgia
Virginia
Maryland
38. Levels of resistance to ivermectin
Number of farms (n=26)
0
2
4
6
8
10
12
Susceptible Suspected Resistance Low resistance Moderate to high
resistance
Full resistance
Georgia
Virginia
Maryland
39. Levels of resistance to moxidectin
Number of farms (n=26)
0
2
4
6
8
10
12
14
16
Susceptible Suspected resistance Low to moderate
resistance
Moderate to high
resistance
Georgia
Virginia
Maryland
40. Levels of resistance to levamisole
Number of farms (n=26)
0
2
4
6
8
10
12
14
16
Susceptible Suspected
resistance
Low resistance Moderate
resistance
High resistance
Georgia
Virginia
Maryland
42. Natural or alternative “dewormers”
Many natural compounds are purported to have “anthelmintic-like”
properties; in fact, the list is overwhelming!
However, studies are generally lacking, inconsistent, and/or not
repeatable.
There is no consistency as to if and how alternative dewormers
have been evaluated or reported in the scientific literature.
Moreover, some natural “anthelmintics” are potentially toxic to the
animal, e.g. copper sulfate, nicotine sulfate.
Considerable research is being done on alternative or natural
“dewormers.”
43. Natural or alternative “dewormers”
(Susan’s current opinion)
Alternative dewormers are not likely to replace commercial
anthelmintics.
However, they may complement commercial dewormers by:
+ Disrupting the free-living stage of the parasite
(e.g. inhibit egg hatching or larvae development)
+ Improving natural immunity of animal
+ Improving overall management of the flock/herd
= Reducing the number of animals that
require treatment with a commercial dewormer.
It’s okay to use alternative dewormers, even unproven ones, so long as you continue to regularly
monitor animals for clinical signs of parasitism and deworm those showing clinical signs.
44. Copper oxide wire particles (COWPs)
A slow release form of copper.
Poorly absorbed as compared to copper sulfate;
thereby, reducing risk of copper toxicity, especially
to sheep.
Sold as a copper supplement for cattle (12.5 g) and
goats (2 and 4 g).
Can (should) repackage cattle product into smaller
doses for sheep and goats: 0.5 to 1 g for lambs and
kids; 1-2 g for mature animals. Selectively treat,
especially sheep.
Administer using small balling gun or PVC pipe with
wooden dowel.
Should determine copper status of animals before
using in sheep.
50. Birthing and weaning management
You can manage lambing/kidding to lessen parasite
problems.
Optimal time to lamb/kid will vary by climate and other
factors.
In Mid-Atlantic region, producers who lamb/kid in winter
and fall report less parasite problems than those that
lamb/kid in spring.
Can keep animals indoors during late gestation/early
lactation to minimize effect of periparturient egg rise.
Weaning age will affect susceptibility to parasites.
There are pros and cons to different weaning ages. Females suffer a temporary loss of
immunity around the time of parturition
Called “periparturient egg rise”
51. Nutritional management
Sheep/goats in better body
condition and on a higher plane
of nutrition are better able to
cope with parasite infections.
Sheep studies have shown
that protein (especially by-pass)
supplementation (above NRC
requirements) in late pregnancy
can reduce fecal egg counts in
periparturient ewes.
In the Mid-Atlantic region, pastures are usually deficient in energy.
53. Zero grazing: pen vs. pasture studies
Fecal egg counts, EPG
2013 2014
0
500
1000
1500
2000
2500
d (-12) d-0 d-14 d-28 d-42 d-56 d-70 d-84
Pen Pasture
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
d (-6) d-0 d-14 d-28 d-42 d-56 d-70 d-84
Pen Pasture
No pen goats required deworming. Pasture goats were dewormed 28 and 5 times, respectively, in 2013 and 2014.
54. Genetic selection
Goats are more susceptible to parasites than sheep.
There are documented differences in breeds with regards
to parasite resistance.
Sheep: Gulf Coast Native, hair sheep with Caribbean (West
African) origins, Texel (?)
Goats: Myotonic, Kiko, Spanish
There is as much genetic variation within a breed as
between breeds.
Parasite resistance (fecal egg counts) is a moderately
heritable trait, 20-40%. It is possible to select for parasite
resistance. One of bucks showing
resistance in 2015 test.
55. Within breed differences
Fecal egg counts are
not evenly dispersed
in a flock or herd.
80-20 rule
Approximately
20-30% of the
flock/herd is
responsible for 70-
80% of the pasture
contamination (egg
deposits).
57. Genetic selection via on-farm evaluation,
central performance tests, and EBVs
RAMS AND BUCKS
Select the best
EWES AND DOES
Get rid of the worst
Never requires deworming
Low egg shedder
Requires frequent deworming
Heavy egg shedder
59. Targeted Selective Treatment (TST)
Only deworming animals which require treatment or
would benefit from treatment.
Never treating the whole group of animals.
Increases refugia
Slows drug resistance
Helps to identify susceptible and resistant animals
Refugia are worms (in animal and on
pasture) that have not been exposed to drug,
thus remain susceptible.
67. 2. BACK: Body condition scoring
BODY CONDITION
Many parasites cause a loss of body
condition.
Poor body condition can also be a sign of
age, poor nutrition, or other diseases.
Animals vary in their ability to hold body
condition.
Body condition scores range from 1-5, with 1
being emaciated, 3 being average and 5
being obese. Half scores are used.
BODY CONDITION SCORING
Is used to assess how fat or thin an animal is.
Cannot be determined simply by looking at
animal.
Is accomplished by feeling for the amount of
fat and muscle over the back, ribs, and loin
edge.
Is one of the most useful management
practices for a livestock producer
Should be done on a regular basis.
68. Score Spineous process Rib cage Loin eye
1 Very thin Easy to see and feel, sharp Easy to feel and can feel under No fat covering
2 Thin Easy to feel, but smooth
Smooth, slightly rounded, need to
use slight pressure to feel
Smooth, even fat cover
3
Good
condition
Smooth and rounded Smooth, even feel Smooth, even fat cover
4 Fat
Can feel with firm pressure,
no points can be felt
Individual ribs cannot be felt, but
can still feel indent between ribs
Thick fat
5 Obese
Smooth, no individual
vertebra can be felt
Individual ribs cannot be felt. No
separation of ribs felt.
Thick fat covering, may
be lumpy and “jiggly”
Source: www.smallstock.info
69.
70. 3. Tail. Fecal soiling. Dag score
The hindquarters of the
animal are assessed to
determine dag score or
degree of fecal soiling.
Many parasites can cause
scours (diarrhea).
Stress and diet are other
causes of diarrhea.
What is a dag? Dried feces left dangling on
the wool on a sheep’s rear end.
71. Score Description Action
0
No fecal soiling at all. No indication for
treatment/action.
None
1 Very slight soiling on edge of tail/on each side None
2 Slight soiling on edge of tail/on each side Usually none
3 Moderate soiling, dag formation Consider treatment/action
4 Severe soiling, severe dag formation Treatment recommended
5
Very severe, watering diarrhea extending to
hocks.
Treatment essential
Source: University of Pretoria, South Africa
72.
73. 4. Jaw: “bottle jaw”
submandibular subcutaneous edema
An accumulation of fluid (swelling)
under the lower jaw of a sheep, goat,
or calf.
Usually a result of anemia (blood loss).
Occurs primarily due to the infestation
of barber pole worms (Haemonchus
contortus) or other blood-feeding
parasites.
Can also be caused by coccidiosis and
other parasites.
74. 5. Nose or coat condition
SHEEP: NOSE
Nasal discharge: for nasal bots
GOAT: COAT CONDITION
The condition of a goat’s hair coat can be indicative
of its overall health and thriftiness.
Diet (nutrition) also has a large effect on coat
condition.
75. The Happy Factor™
“A happy sheep is a healthy sheep.”
Developed in Europe and New Zealand,
where barber pole worm is not the
primary parasite, but “scour” worms are.
Performance-based model; deworm
when animals fail to meet performance
targets.
Live weight gain
Milk production
Will be most practical with use of
individual electronic ID and automatic
weighing platforms.
More information/research needed. Not tested for barber pole worm: will it work?
76. Other factors to consider when deciding to
deworm an animal
Fecal egg count
Fecal consistency
Scores of other animals
Previous scores
Risk of re-infection
Plane of nutrition
Frequency of checking
Performance
77. When deworming is not enough
Remove from contaminated pasture to avoid
re-infection and minimize environmental
stress.
Give supportive therapy.
Electrolytes
Protein/energy supplements
Vitamin/mineral supplements
Provide high protein feed that is palatable.
80. Why give a combination treatment?
Research has shown that combination treatments
are the best approach.
Unlike rotating dewormers, you get an additive
effect.
By achieving a higher efficacy, there are fewer
resistant worms surviving treatment.
The sooner you start using a combination, the
better off you will be.
When combined with other “best management
practices,” combination treatments increase
refugia, prevent resistance from developing
further, and may result in a reversion back to
susceptibility.
Drug 1 Drug 2 Drug 3 Combo12 Combo123
80% 80% 80% 96.00% 99.20%
90% 90% 90% 99.00% 99.90%
60% 95% 98.00% 98.00%
60% 60% 95% 84.00% 99.20%
99% 99% 99.99% 99.99%
60% 60% 60% 84.00% 93.60%
50% 50% 50% 75.00% 87.50%
40% 40% 40% 64.00% 78.40%
95% 80% 20% 99.00% 99.20%
81. Recommended combination treatment
Valbazen® Cydectin® Prohibit®*
Sheep 1.5 ml/50 lbs.
[7 days]
4.5 ml/50 lbs.
[7 days]
Depends on dilution
[3 days]
Goats 4 ml/50 lbs.
[9 days meat]
[7 days milk]
9 ml/50 lbs.
[17 days meat]
[8 days milk]
Depends on dilution
[4 days meat]
[3 days milk]
83. Using copper oxide wire particles
(COWPs) to increase dewormer efficacy
Treatment
(10-23 lambs per Tx group)
Efficacy
(%FECR)
No treatment (control) Increase
Valbazen® (3 ml/50 lbs.) 20%
COWP (2 g, Ultracruz™) 58%
COWP (2 g, Copasure®) 12%
Valbazen® + COWP 99%
Similar results would be
expected if COWPs were
combined with other
dewormers (e.g. Prohibit®).
USDA ARS (Booneville, AR) Study, Published 2016.
85. Fecal egg counting
Determine efficacy of treatment
Fecal egg count reduction test
Monitor pasture contamination
Identify resistant/susceptible animals
By themselves, fecal egg counts are not a
reliable diagnostic tool for determining the
need to deworm an individual animal.
86. What you need to do your own fecal egg
counts
Microscope
100x magnification (10x10=100x)
Mechanical stage useful
McMaster egg counting slide
Flotation solution
Gram scale
Cups or vials
Craft stick or tongue depresser
Cheese cloth or tea strainer
Pipettes or syringes
Gloves
87. Modified McMaster Procedure
1) Weigh out 4 g of feces
2) Add 26 ml of flotation solution
3) Crush and mix feces using stick
4) Drain solution through cheese cloth or tea strainer into a clean cup
5) After stirring solution, draw up solution from top of mixture
6) Fill both sides of slide chamber.
7) Allow slide to sit for 5-10 minutes
8) Place slide on microscope
9) Focus on grid
10) Count strongyle-type eggs inside of and under grid lines
11) Record number of eggs for each grid.
12) Multiply their sum by 25 to get EPG
Note: If using 2 g of feces, add 28 ml of flotation solution and multiple number of eggs in both chambers by 50.
88.
89. Limitations of fecal egg counts
Not a highly accurate test, especially at low numbers.
Parasites vary in their egg producing capacity.
Immature worms (L4s) suck blood, but do not lay eggs.
Inhibited larvae do not lay eggs.
There is a day-to-day variability in counts, even in stable
worm populations.
Eggs are not always evenly distributed in manure.
Loose stools (diarrhea) may underestimate egg counts.
Some eggs look the same and cannot be differentiated at
the egg stage (e.g. Haemonchus vs. Trichostrongylus)
Not all parasites (or strains) are pathogenic.
There are different procedures for doin g fecal egg counts.
The possibility of human error.
Snapshot in time: not useful without other information.