2. Life Cycle Gastrointestinal Nematodes
Short life cycle. On average
2 to 3 weeks, and as short
as 7 days
Has a direct life cycle. No
intermediate host is required
L1
L2
L3
4. The Barber Pole Worm is the parasite of
primary concern in the U.S.
Barber Pole Worm
5. Haemonchus contortus
• Common names: barber
pole, wire worm, large
stomach worm.
• Blood-sucking roundworm
that pierces the mucosa of
the abomasum, causing
blood and protein loss to
the host.
6. Haemonchus contortus
• Needs warm (60°F), moist
conditions to complete its
life cycle.
• Pasture is the primary
mode of transmission.
–It is estimated that 80%
of the worm larvae is
found in the first two
inches of grazing
vegetation.
8. Barber Pole Worm Control
• Is a prolific egg producer.
Has been estimated that 30% of the
flock is responsible for 70% of the egg
output
• Is very adaptable.
Can go into a hypobiotic (arrested)
state in the animal to survive poor
environmental conditions
11. Barber Pole Worm Control
• Is very resilient
Can survive on pasture for a long time
60 days pasture rest is needed to reduce
pasture contamination to a low level
Some larvae survive over winter
Has become resistant to most anthelmintics
THE PROBLEM TODAY!
13. Symptoms of Barber
Pole Worm
Infection…
• Death
• Loss of Body Condition
• Anemia (pale mucous
membranes)
• Edema – “bottle jaw”
accumulation of fluid under jaw
15. What is FAMACHA???
• A novel system for monitoring
barber pole worm infection in
small ruminants
• Developed in South Africa due
to the widespread emergence
of drug resistant worms
• Originally developed for South
African sheep, but has been
validated for sheep and goats
in the United States
18. What FAMACHA does…
Reduces the number of
animals dewormed (though
some may need treating more
often)
Saves money on drugs
Reduces drug use
Reduces selection for resistant
worms, by increasing refugia:
(worms not exposed to drugs)
Prolongs effectiveness of anthelmintics
19. What FAMACHA does…
Identifies susceptible and resistant animals in
the flock (parasite resistance is moderately
heritable)
Assists with selection and culling decisions
Adds value to breeding stock
20. How to make FAMACHA work
• Always use the card
• Do not use a copy of the
card
• Keep card in location where
it will not fade
• Check flock often (every 2-3
weeks during the “worm”
season)
• Have an easy way to handle
your animals
21. What FAMACHA will not do...
1)Eliminate the need for other
parasite control practices
2)Save you time
–You may deworm less frequently,
but you’ll spend more time
checking your animals
3)Help with other potential parasite
problems
–Other GI worms
–Coccidia, etc.
23. Classes of Dewormers
The three general classes of dewormers are
benzimidazoles, Levamisole and Macrolytic
Lactones
24. Classes of Dewormers
I-Benzimidazole - Fenbendazole (Safeguard, Panacur) and
Albendazole (Valbazen)
II-Levamisole - Levisol, Tramisol and Morantel Tartrate
(Rumatel)
III-Macrolytic Lactones - Ivermectin (Ivomec) and Moxidectin
(Cydectin)
Only Fenbendazole, Albendazole and Morantel Tartrate
were approved for use in small ruminants. Others have been
used as extra-label. A number of dewormers have gone off-
patent now and are marketed under different generic names
25. Resistance
The major problem in controlling parasitism in small
ruminants is genetic resistance to most all dewormers
Resistance has developed primarily due to dewormers
being used and rotated too frequently. Many times
under-dosing occurs
Continued rotation of dewormers will increase selection
of more resistant worms in animals which will result in a
population of "superworms" that can not be controlled
with drugs
26. Resistance
Resistance is genetically controlled, and once
established, set in the population. Those dewormers
can no longer be used effectively.
Only change dewormers when one does not work, then
change between classes of dewormers.
*New research has
Indicated use of two
products at once may
be more effective*
27. We are currently seeing that
worms have become resistant
to most of the anthelmintics.
As a rule of thumb, 70% of
parasite infection comes from
30% of the flock. Identify
resistant genetics in your
flock! Cull parasite carriers!
Resistance to Anthelmintics
28. Only 3 drug families!
Benzimidazoles
Levamisoles
Macrolytic Lactones
Resistance occurs
when anthelmintic
treatment fails to
reduce worm egg
count by 90%.
Severe resistance
exists when
anthelmintic reduces
egg count by less
than 60%
Resistance to Anthelmintics
29. New research indicates
that use of two different
type of dewormers at the
same time can increase
the effectiveness of both
and eliminate more
resistant parasites as a
result.
Use of Two Dewormers….
30. If two drugs each with 90% efficacy are used in
rotation, then each time animals are treated,
10% of the worms survive (the resistant
ones). In contrast, if these same two drugs are
used in combination at the same time, then the
efficacy increases to 99%.
Use of Two Dewormers….
31. Administration of Dewormers
Oral administration is preferred; and with
drenches, it is very important to make sure the
product is delivered over the base of the tongue
By doing so, the dose is
delivered to the rumen
and then distributed
evenly throughout
the gastrointestinal tract
32. Administration of Dewormers
The other form of oral administration is in feed
products.
This does not ensure
that all animals will
receive an effective
dose because
Individual animals
utilize these products differently
34. Sustainable parasite control
&
Integrated parasite control
Sustainable parasite control: minimize animal production loss, preventing
parasitic diseases, avoiding anthelmintic resistance (Besier, 2012). Uses the
REFUGIA concept.
Integrated Parasite control: somehow is a sustainable parasite control that
integrates chemical and nonchemical options (Kahn and Woodgate, 2012).
Smart use of anthelmintics includes knowledge on host physiology,
anthelmintic pharmacokinetics, parasite biology, and the status of anthelmintic
resistance on the farm. This increases the efficacy of treatments, and reduces
the drug resistance (Kaplan, 2004)
36. Strategic Parasite Control
Prevention is the best method for controlling parasites
Successful parasite control means reducing or
eliminating
environmental
contamination:
37. Strategic Parasite Control
Steps should include several key goals
1) Animals should be as free of parasites during periods of low or
reduced nutrition such as during the wintertime
2) The females should be free of parasites at kidding/lambing time
3) Recontamination of spring pastures should be eliminated for
the first three months of the grazing season
38. Keep in mind that
regularly deworming all
of your flock is not a
sustainable practice.
You need to be
selectively deworming
your goats and sheep.
Sustainable Practice
39. • Pasture rest/rotation
• Safe pastures
• Multi-species grazing
• Management of grazing height
• Alternative forages/treatments
• Nutritional supplementation
• Zero grazing
• Fecal egg analysis
• Proper anthelmintic use
• Selective deworming
Integrated Parasite Management
(IPM)
40. Targeted selective treatment
TST is deworming only those animals that really requires
being dewormed, uses productive performance (milk
production) (Hoste et al., 2002) or daily gain weight, other
indicators such as anaemia (van Wyk and Bath, 2002)
(FAMACHA) and body condition.
TST keeps REFUGIA: population of parasites not exposed
to anthelmintic that survive and “dilute” in the environment
those resistant parasites that survived treatment. Avoiding
only resistant parasites to infect most of the flock.
50. Parasite Control…
Control and prevention need to be planned
–Select animals for parasite resistance
–Grazing management
• Don’t let grass get lower than 4”
• Longer rest periods help break the cycle
(>40 days)
–Strategic deworming program
–FAMACHA
51. Other Parasites…
“Cousins” of the barber pole worm cause
digestive problems, e.g. scouring
–Teladorsagia circumcincta
–Trichostrongylus spp.
–Nematodirus
Tapeworms-
Only worm that is
visible in the feces
55. Predator Control…
Guard dog and fencing that is 5 - 8 wire high
tensile power fence or net wire with wider mesh.
56. Fencing…
High Tensile electric/power
–5-8 wire perimeter at least 40”-42” tall, the
bottom wire 6”-8” from the ground and 6”-
12” spacing between wires
–2-6 wire interior
–Ground rods every 1,300’-2,600’
58. Fencing…
Woven Wire
(Galvanized high tensile is available)
–39” tall and at least 1 barbed strand
–6”x12” mesh is preferred to minimize horns
being caught
–May run an electric offset wire 12”-15” from
the ground to reduce animals getting
caught or climbing on fence
63. Utilize Proper Stocking Rates…
Lower stocking rates and higher residuals will
generally have less of a parasite build up in the
pasture
64. How Many Per Acre?
Stocking rates vary by:
–Pasture quality
–Rainfall
–Forage species
–Time of year
–Soil fertility
–Amount of supplementation
–Grazing management (continuous, rotational
or intensive)
65. Stocking rate…
6-8 head per acre is usually a safe stocking rate
on well managed pastures for small ruminants
66. Grazing Preferences…
Goats
–Prefer browse over grass
–Prefer forbs over grass
–Prefer grass over clover
–Prefer taller plants
–Tend to graze perimeter
before center of pasture
–Graze from the top down
69. Utilize Grazing Behavior…
Higher from the ground animals graze, the less
likely they are to pick up parasite larvae
High tannin diets reduce reproduction of internal
parasites
70. Utilize Grazing Behavior…
Plants with high tannins or compounds that help
control internal parasites
Sericea lespedeza Annual Lespedeza
Birdsfoot trefoil Arrowleaf Clover
Berseem Clover Crown Vetch
Chicory Oak Leaves
Walnut Leaves Mulberry
Mimosa Acacia
Autum Olive Multiflora-Rose
71. Spring Grazing…
Keep pasture vegetative
Rotate frequently to increase the intake of high-
quality plants and prevent regrowth from being
eaten too soon
Rest pastures 20-30-days to allow plants time to
recover
72. Summer Grazing…
Try to have cool season pastures fully utilized by
the end of June and then rest all summer if
possible
Graze warm season grasses such as lespedeza,
chicory, etc.
73. Fall/Winter Grazing…
Start using cool season pastures
–By this time they have had 60-90 days of rest
during the summer
–Defer grazing on some pastures to stockpile
for winter grazing
74. Fall/Winter Grazing…
Allow warm season pastures to rest all winter
Rotate similar to spring but stay in each pasture a
little longer to give a longer rest period (35-40)
days
–Forage quality won’t drop as quickly in the fall
Utilize stockpiled grasses for winter feeding
–Strip graze to improve utilization
Refugia-based strategies for sustainable worm control: Factors affecting the acceptability to sheep and goat owners
Besier, R.B.
Integrated parasite management: Products for adoption by the Australian sheep industry
L.P.Kahn, R.G.Woodgate, 2012
Responding to the emergence of multiple-drug resistant Haemonchus contortus: Smart drenching and FAMACHA®
R.M. Kaplan, 2004
NO ROTATION OF DEWORMERS because you Will be exposing worms to all the compounds
5 POINT CHECK
BIOWORMA
.By minimising exposure to drug, refugia-based control strategies aim to conserve susceptible alleles within the parasite population. The resulting mixture of resistant and susceptible genotypes on pasture should then allow the potential for cross-breeding and/or dilute the frequency of resistant genotypes within a population
IN PRACTICE 91 . MAY 1984
Farm Practice
Body condition scoring
of sheep
by Angus Russel
Nematode species
H. contortus (abomasum),
T. circumcincta (abomasum) and
T. colubriformis (small intestine)
All are from the superfamily Trichostrongyloidea.
Understanding