Download Parasites of Goats By Page Bishop 12-01-2005

Parasites of Goats
By
Page Bishop
12-01-2005
Parasites
• It is important to realize that each region of the country will have
different parasite problems and potentially different
prevention/treatment programs. Therefore, it is important to involve
a local veterinarian in all parasite control programs. Proper nutrition
is of extreme importance in the control of the effects of parasitism.
Animals in good condition and receiving adequate feed are often
able to establish some resistance to internal parasites. Poorly fed
animals are unable to cope with parasitism, and death losses are
often great. Parasitic disease problems increase with intensification
of production and lack of attention to strict sanitation.
• In general, parasites can be broken into two major categories:
internal parasites (endoparasites) and external parasites
(ectoparasites). Each parasite is then further classified into
additional groups according to their structure, growth, and life
cycles.
Internal Parasites
• Internal parasites may be divided into four (4)
classifications:
• Roundworms - (Nematodes)
• Tapeworms - (Cestodes)
• Flukes - (Trematodes)
• Protozoa - (Coccidia)
Roundworms - (Nematodes)
• The roundworms are by far the most economically
important internal parasites of goats. Flukes produce
damage of economic importance in some geographic
areas, while adult tapeworms are usually of minor
importance.
Roundworms - (Nematodes)
•
Large stomach worm, barber pole worm, twisted worm - Haemonchus
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Brown stomach worm - Ostertagia
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Stomach/intestinal hairworm, small stomach worm – Trichostrongylus
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Thread-necked worm - Nematodirus
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Hookworm - Bonostomum
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Nodular worm – Oesophagostomum
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Large-mouthed bowel worm – Chabertia
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Whipworm - Trichuris
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Large lungworm - Dictyocaulus filaria
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Cooperia
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Strongyloides
Large stomach worm, barber pole worm,
twisted worm
- Haemonchus
• Description: Internal parasite. Adults are
10 – 30 mm long. Males are shorter than
females and have an even, reddish color
and a bursa with an asymmetrical dorsal
lobe and barbed spicules. Females are
identified as barber’s pole worms because
their white ovaries are wound around their
red blood-filled intestine.
• Life Cycle: Eggs laid by adults in the
abomasum are passed in the feces and
hatch on the ground. On pasture they
undergo a typical series of molts, becoming
infective in about 4 – 6 days. Cattle then
ingest the larvae, beginning the infection.
Fertile adults appear in approximately 28
days, but it is important to note that signs of
the disease can appear sooner because
larvae and immature adults, as well as
fertile adults, suck blood.
Brown stomach worm
- Ostertagia
• Description: Internal parasite. Before the
larval forms are ingested, their development in
the environment may have been arrested by
hypobiosis, a survival mechanism in which the
preparasitic stages on-pasture "avoid" adverse
summer and winter conditions. Ostertagia is
one of the most economically significant
parasites of cattle.
• Life Cycle: Adults in the abomasum lay eggs
that pass in feces. Once hatched, larvae
undergo two molds to become infective thirdstage larvae which migrate onto herbage and
are ingested by grazing cattle. Once ingested,
these parasitic larvae grow and molt twice
more to become egg-laying adults. The
prepatent period is 18-25 days, though
hypobiosis affects the process.
Stomach/intestinal hairworm, small stomach worm –
Trichostrongylus
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Description: The adult worm is small (0.5 centimeter long) and hair like.
Predilection sites: Stomach glands, small intestine.
Geographic distribution: Widespread in the US.
Life cycle: Trichostrongylus axei has a direct life cycle typical of nematodes.
Larvae develop to infectivity on pasture in 4 to 6 days under optimal
conditions of temperature and humidity.
• Significance: The stomach hairworm is important primarily in contributing to
burdens of mixed worm species.
• Clinical effects on host: Trichostrongylus is usually part of a mixed
infection, so its results are additive. The hairworm irritates and erodes the
villi of the gut, damaging the capillaries and lymph vessels within these
structures and causing blood loss into the gut. Parasite-induced trauma to
the intestinal lining results in characteristic dark, foul-smelling diarrhea.
Blood loss can cause anemia, edema, and rapid loss of condition.
• Diagnosis: Larvae can be identified by fecal culture – the small egg is not
identifiable by species.
Thread-necked worm -
Nematodirus
• Description: Internal parasite. Adults are up to 25 mm long.
• Life Cycle: Eggs develop slowly; the infective third stage is
reached within the egg in 2 – 4 weeks and may remain within
the egg for several months. Eggs are highly resistant, and
those passed by calves in one season can infect calves the
next. After ingestion of infective larvae, the adult stage is
reached in approximately 3 weeks.
• Geographic Distribution: Worldwide.
• Significance: Heavy infections of Nematodirus can lead to
decreased weight gain, particularly when other parasites are
present. Larval stages are primarily responsible for harming the
host animal. Large numbers of larvae can retard an animal’s
growth and even cause destruction of the intestinal wall.
Hookworm - Bonostomum
• Anterior end is bent toward its
back. The mouth is cup-shaped
and has two cutting plates.
Males are 12-17 mm long;
females are 19-26 mm
• Can cause anemia, edema, and
general unthriftiness. Symptoms
are generally similar to those of
the stomach worm. Adult worms
attach to the intestinal wall and
suck blood. Bleeding often
continues even after the parasite
is gone.
Nodular worm –
Oesophagostomum
• Description: Internal parasite. Adult worms are stout bodied and 14
– 22 mm long.
• Life Cycle: Adults in the intestine lay eggs which are passed in
feces. Larvae pass through a series of molts and reach the infective
third stage in approximately 7 days. When ingested with herbage,
the larvae penetrate the wall of the host animal’s intestine, forming
nodules anywhere between the stomach and the rectum. After 5 – 7
days they return to the intestinal lumen and travel to the colon,
where they undergo a final molt and mature into adults. Eggs appear
in the feces about 41 days after the larvae are ingested.
• Geographic Distribution: Worldwide, particularly in wet, temperate
climates.
• Significance: Infective larvae burrow into the intestinal wall, causing
the formation of pea-sized nodules called granulomas. Granulomas
impair intestinal function, particularly fluid absorption. The result is
black, foul diarrhea which is very debilitating. The disease
oesophagostomiasis is characterized by anemia and edema in
addition to the explosive diarrhea. When worms are present in large
numbers. Young stock in particular are affected seriously and can
die.
Large-mouthed bowel worm –
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Chabertia
General Description: Nematodes with a large oral
opening. Males are 13 to 14mm long, females, 17 to
20mm.
Life Cycle: Direct life cycle. Infection by ingestion of
infective third stage larvae. Prepatent period is about 48 to
54 days.
Location: Colon
Geographical Distribution: Worldwide
Significance: Chabertia is significant only in heavily
infected sheep. Reduced wool growth is the major result.
Effect on Host: Adults ingest plugs of the bowel wall;
some bleeding may occur. The affected part of the
intestine is mildly irritated. Anaemia may occur when
severe infections exist. Replacement of tissue and blood
lost to parasites limits the energy the host may otherwise
use for wool growth. Occasional diarrhoea may be seen.
Diagnostic Information: Strongyle-type eggs appear in
faeces.
Control: Treatment of infected sheep with a suitable
anthelmintic.
Whipworm - Trichuris
• Description: Internal parasites. Long
roundworms; the anterior part is long and thin
while the posterior is much thicker, giving the
appearance of a whip. The male posterior is
curved.
• Life Cycle: Infective larvae develop within eggs
after at least 3 weeks on pasture. The eggs are
resistant to cold temperatures and dry conditions,
and can therefore remain infective for years.
Cattle become infected by ingesting embryonated
eggs. Adults develop in 1 – 3 months.
• Geographic Distribution: Widespread.
• Significance: The effects of whipworm infection
have not been determined, as affected animals
exhibit clinical signs only occasionally. Those that
do, experience typical "parasite worry“ and do not
feed or sleep well. Scratching may produce skin
wounds or bruises, and the coat becomes rough.
Infestations with biting lice are heaviest in winter
when cattle hair coats are thick.
Large lungworm - Dictyocaulus filaria
• White with a dark line running the full length of the worm.
Length of males are 3 to 8 cm and females range from 5 to 10
cm.
• Accumulation of adult worms and eggs can occur in the airways
and cause obstruction. This can cause the lung tissue to
collapse. Suffocation can then occur. Animals can show a
symptoms by coughing and having difficulty breathing.
Cooperia
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Cooperia species are nematodes of the small intestine of ruminants. Species in
domestic animals are usually 5-9mm long and males have a prominent bursa in
relation to their size. Cooperia curticei is easily recognized on microscopic
examination by its coiled appearance that has been described as like a "watch
spring", as shown in the accompanying image of a female.
Cooperia are generally considered to be mild pathogens. They contribute secondary
effects to the primary pathogens Ostertagia and Haemonchus in parasitic
gastroenteritis. However, Cooperia punctata, pectinata and suranabada are believed
to be more pathogenic since they penetrate the mucosa during larval development
causing changes similar to those of intestinal species of Trichostrongylus
Strongyloides
•
Strongyloides stercoralis is an unusual
"parasite" in that it has both free-living and
parasitic life cycles. In the parasitic life cycle,
female worms are found in the superficial
tissues of the human small intestine; there are
apparently no parasitic males. The female
worms produce larvae parthenogenically
(without fertilization), and the larvae are passed
in the host's feces. The presence of nematode
larvae in a fecal sample is characteristic of
strongylodiasis. Once passed in the feces,
some of the larvae develop into "free-living"
larvae, while others develop into "parasitic"
larvae. The "free-living" larvae will complete
their development in the soil and mature into
free-living males and females. The free-living
males and females mate, produce more larvae,
and (as above) some of these larvae will
develop into "free-living" larvae, while other will
develop into "parasitic larvae."
Tapeworms
• Broad tapeworm - Moniezia expansa
• Fringed tapeworm - Thysanosoma
actinioides
• Hydatid cysts - Echinococcus granulosus
• Cysticercosis - Taenia ovis
• Taenia hydatigena
• Gid - Taenia multiceps
Broad tapeworm
- Moniezia expansa
The life cycle of Moniezia expansa involves sheep as the definitive host and soil mites
as the intermediate host. The tapeworm's eggs are passed in the sheep's feces, and
mites are infected when they eat the eggs; the metacestode stage in the mite is called a
cysticercoid. Sheep are infected when then ingest infected mites. This species of
tapeworm is unusual in that each proglottid contains two sets of female reproductive
organs
Fringed tapeworm - Thysanosoma actinioides
• Definitive hosts: ruminants
• Site of infection: small intestine
Typical size: up to 30 cm long
•
Distribution: cosmopolitan
•
Intermediate hosts: cysticercoids
develop in psocid lice; these lice are
ingested along with vegetation
Hydatid cysts - Echinococcus granulosus
• The life cycle of Echinococcus granulosus includes dogs (and
other canines) as the definitive host, and a variety of species of
warm blooded vertebrates (sheep, cattle, goats, and humans)
as the intermediate host. The adult worms are very small,
usually consisting of only three proglottids (total length = 3-6
mm), and they live in the dog's small intestine. Eggs are
liberated in the host's feces, and when these eggs are ingested
by the intermediate host they hatch in the host's small
intestine. The larvae in the eggs penetrate the gut wall and
enter the circulatory system. The larvae can be distributed
throughout the intermediate host's body (although most end up
in the liver) and grow into a stage called a hydatid cyst.
Cysticercosis - Taenia ovis
Taenia hydatigena
• The life cycle of the Taenia tapeworm
starts in the host’s intestine, the host
being a dog or cat. The worm can be
unbelievably long (up to 5 yards for
Taenia hydatigena) and is made of
segments. Each segment contains an
independent set of organs with new
segments being created at the neck
and older segments dropping off the
tail. As segments mature, the
reproductive tract of the segment
becomes more and more prominent
until it consists of a bag of tapeworm
eggs. These segments, called
proglottids, are passed with the feces
into the world where an unsuspecting
intermediate host (mouse, rabbit,
deer, goat etc.) swallows one while
feeding.
Gid -
Taenia multiceps
• The life cycle of this parasite involves warm blood vertebrates
as both the intermediate and definitive hosts.
• Infections with cenuri can cause pathology in the intermediate
host. Human infections (acquired by accidental ingestion of
eggs) have been reported. The cenuri of T. multiceps
(sometimes called Cenurus cerebralis) can infect the brains of
sheep/goats, causing a disease referred to as "gid" or
"staggers." These terms refer to the behavior of sheep/goats
infected with this parasite.
Flukes - Trematodes
• Common liver fluke - Fasciola hepatica
Flukes - Trematodes
• The common name of this parasite, the "sheep liver fluke," is somewhat
misleading since this parasite is found in animals other than sheep
(including cattle and humans), and the parasite resides in the bile ducts
inside the liver rather than the liver itself. This species is a common
parasite of sheep and cattle and, therefore, relatively easy to
obtain. Thus, in introductory biology or zoology courses, it is often used
as "THE" example of a digenetic trematode. This species has been
studied extensively by parasitologists, and probably more is known
about this species of digenetic trematode than any other. The adult
parasites reside in the intrahepatic bile ducts, produce eggs, and the
eggs are passed in the host's feces. After passing through the first
intermediate host (a snail), cercariae encyst on vegetation. The
definitive host is infected when it eats the contaminated vegetation. The
metacercaria excysts in the definitive host's small intestine, and the
immature worm penetrates the small intestine and migrates through the
abdominal cavity to the host's liver. The juvenile worm penetrates and
migrates through the host's liver and finally ends up in the bile ducts
(view a diagram of the life-cycle). The migration of the worms through
the host's liver, and the presence of the worms in the bile ducts, are
responsible for the pathology associated with fascioliasis.
Flukes - Trematodes
Protozoa - Coccidia
• Coccidia (coccidiosis) - Eimeria
Protozoa - Coccidia
• The diseases caused by these parasites
are referred to collectively as coccidiosis,
and they vary tremendously in
virulence. Some species cause diseases
that result in mild symptoms that might go
unnoticed (i.e., mild diarrhea) and
eventually disappear, while other species
cause highly virulent infections that are
rapidly fatal.
Protozoa - Coccidia
•
A host is infected when it ingests oocysts that have been passed in the
feces of another host. The oocyst excysts in the host's small intestine, and
the sporozoites contained within the oocyst are liberated. The sporozoites
penetrate the cells of the host's small intestine and reproduce
asexually. Each generation of asexual reproduction produces multiple
merozoites; the merozoites are liberated from the cell and infect new
cells. It is this stage of the infection that can result in destruction of massive
numbers of cells in the host's small intestine and, ultimately, lead to the
host's death. Some of the merozoites that enter the host's cells transform
into gametocytes. The gametocytes transform into gametes, the gametes
fuse, and the resulting zygote begins to develop into an oocyst. The
developing oocyst escapes from the host's cell, and it is passed in the host's
feces. Typically, when the oocyst is passed in the feces, it is not infective
because it does not contain sporozoites; this is an unsporulated
oocyst. After several days (or weeks, depending on the species) outside of
the host's body, the oocyst completes development and sporozoites are
found within; this is a sporulated oocyst, and it is infective to the next host
Protozoa - Coccidia
A severe
coccidiosis infection
in a small animal
Diagnosis of Internal Parasites
•
Most of these infections can be detected using a fecal egg count. This is
done by collecting a fecal sample and sending it to a local veterinarian for
fecal flotation.
Pictured (left) is the procedure for preparing a
fecal flotation. To perform the test, mix about
1 gram of feces thoroughly with water (about
15ml). Strain the mixture to remove the larger
debris, and then centrifuge for five minutes or
let stand for twenty minutes. Next, pour off
the supernatant and mix the sediment with
sugar water. Place a coverslip on the top of
the centrifuge tube, in contact with the sugar
meniscus, and repeat centrifugation for
another five minutes. Then place the
coverslip on a slide and examine for parasite
eggs or oocysts. The species of the parasite
found will determine the extent of the clinical
significance.
Treatment/Prevention
• To stop intestinal worms from accumulating, do not use the same pastures
for kidding every year.
• Rotate pastures used for grazing every 3-6 months.
• If clean grazing such as stubble is available, goats should be given an
effective broad spectrum de-wormer before they are moved on to it.
• If possible, all animals that are de-wormed should be held in a dry lot for at
least 3 days. This is because most de-wormers do not kill the parasite eggs,
just the adults worms. Waiting 3 days will help the animal eliminate most of
the parasite eggs in the dry lot and not on pasture where other animals may
ingest the eggs.
• Prevent the post-kidding rise in parasite egg production.
• Have a veterinarian perform a fecal egg count to check the effectiveness of
any de-worming or parasite control programs. This should be done 10-14
days after de-worming. Use these fecal egg counts to determine whether
goats need additional de-wormings.
• Avoid resistance problems by not using the same products year after year.
• Select for animals that are parasite-resistant. These are goats that have a
natural resistance to internal parasites. These animals are often identified
through the use of fecal egg counts.
De-worming Program for Internal Parasites
• In colder climates where the animals are moved off of pasture
for the winter, a dose can be given just before the move is
made.
• A second time for de-worming occurs 1 month prior to the
kidding season. De-worming does about 2-4 weeks before
kidding and then moving them to a safe pasture, will prevent
the rise in production of worm eggs after kidding. If the does are
not moved after this dose, additional doses are required at 3
week intervals throughout the kidding season. The final dose
should be given 2-4 weeks after the last kid is born.
• A de-wormer for kids at weaning should also be given. After the
de-worming, the kids should be moved to a "safe" pasture.
• Breeding males are often de-wormed 1 month before the
breeding season
Products Used to Treat Internal Parasites:
*Ivomec Sheep Drench (Ivermectin)
*Tramisol or Levasole (Levamisole)
*Bovatec (Lasalocid Sodium)
*Rumensin (Monensin
*Corid (Amprolium)
*Dectomax (Doramectin)
*Valbazen (Albendazole)
*Panacur (Fenbendazole)
* Many of these products are not labeled for use in goats.
Their use in these cases is considered "extra-label."
External Parasites Common to Goats:
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Lice - Damalinia
Mites - Chorioptes, Psoroptes, Sarcoptes, Demodex
Flies - Lucilia, Calliphora, Chrysomya
Ked - Melophagus ovinus
Ticks
Nasal bot - Oestrus ovis
Lice - Damalinia
Goat lice affect only goats. They may
survive on sheep for about 5 to 7 days,
but not propagate. Lice from cattle do
not affect goats.
Lice spend their whole life on the goat.
Individual adult lice survive for about a
month.
The spread of lice is by direct contact
between goats. Crowded conditions for
goats enable rapid spread. At
shows, spread can occur with shared
grooming equipment, stalls or trailers.
Lice - Damalinia
Mites - Chorioptes, Psoroptes,
Sarcoptes, Demodex
• Mites are barely visible to the naked eye.
The unsegmented abdomen is joined to the
cephalothorax with little or no indication of
separation.
• The adults are found in a wide variety of
locations and under a wide variety of
environmental conditions. Usually, the eggs
are deposited on the soil surface, in
crevices, or in some instances, under the
skin of the host that they infest. The larvae
that hatches (six-legged) seeks a blood
meal and molts to an eight-legged nymph.
More feeding and molting result in adult
mites.
Mites - Chorioptes, Psoroptes,
Sarcoptes, Demodex
Flies - Lucilia, Calliphora, Chrysomya
Flies - Lucilia,
• It is responsible for initiating
over 90 per cent of all
flystrikes. The adult fly is
metallic green/bronze in
colour. Unlike the native
blowflies, Lucilia cuprina
breeds mostly on living sheep.
Females
are attracted to the smell of
fleecerot and lay about 250
eggs in
clusters in damp fleece. Body
length head:abdomen is 9mm.
Calliphora
• Calliphora stygia - the
Eastern Golden Haired
Blowfly - is a native brown
blowfly that prefers cooler
conditions. It occurs in largest
numbers in spring and
autumn, but may be found on
sunny days in winter as well.
It disappears during the heat
of summer. Although this
species mainly breeds in
carcasses, it can be
troublesome in spring especially in does with
kidding stain. Body length
head:abdomen is 13mm.
Chrysomya
•
Chrysomya rufifacies, the green
hairy maggot blowfly, is a secondary
blowfly species. This means it normally
does not strike goats or blow carcasses
until primary maggots, like Lucilia or
Calliphora, are already feeding. The
adult fly is metallic green but can be
distinguished from Lucilia by the broad
bands on its rounder abdomen and by
its black forelegs. The larvae, or "hairy
maggots" appear dark and have sharp
spines over much of the body. These
maggots repel - and will actively feed
on - primary maggots in carcasses. By
doing this they help control Lucilia and
so can be regarded as beneficial flies.
However, on goats, they can cause
extensive damage not only to the skin
but also to the underlying tissue of
struck goats. By the time these larvae
reach full size on goats the animal has
been struck for more than a week initially by Lucilia, but then by
Chrysomya. The very similar, but
smaller, Chrysomya varipes fulfils a
similar role. C. rufifacies is 9mm from
head to abdomen.
Flies - Lucilia, Calliphora, Chrysomya
Ked - Melophagus ovinus
• Description: flat, leathery, reddish-brown insect
about ¼ inch long; resembles a large tick but has
only six legs and is a wingless, bloodsucking fly; a
noticeable piercing mouthpart projects forward from
the head.
• Damage caused: blood loss from keds may cause
anemia in young lambs and reduced rate of gain in
older lambs; keds and their pupae in wool result in
"dirty wool" classification; sheep’s immune response
to keds reduces capillary flow in skin resulting in
reduced quantity and quality of wool; punctures
from feeding cause "cockle" and downgrades hide
value.
• Method of dispersal or infestation: host-to-host
contact facilitated by the sheep’s close herding
behavior and at breeding and nursing; keds move in
great numbers from shorn adults to lambs; some
dispersal between herds is via human handlers and
on shearing equipment.
• Seasonality: numbers are highest during cool
weather, especially on previously uninfested sheep
that have not yet developed a protective immune
response to keds.
Ticks
• The Brown dog tick
seldom attacks animals
other than dogs. It is most
likely found where dogs
are kept in or around the
house. The brown dog tick
is not known to transmit
diseases to humans but
may transmit disease
among dogs.
The American dog tick is
also a common pest of pets
and humans in Florida. Dogs
are the preferred host,
although the American dog
tick will feed on other
warmblooded animals. The
nymphal stages of the
American dog tick usually
only attack rodents.
Ticks
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The female dog tick lays 4000-6500 eggs and
then dies. The eggs hatch into seed ticks in
36-57 days. The unfed larvae crawl in search
of a host and can live 540 days without food.
When a small rodent is found, the larvae
attach and feed for approximately 5 days. The
larvae then drop off the host and molt to the
nymphal stage. The nymphs crawl about in
search of a rodent host, attach to it, and
engorge with blood in 3-11 days. Nymphs can
live without food for up to 584 days.
Adults crawl about in search of dogs or large
animals for a blood meal. Adults can live for up
to 2 years without food. American dog tick
adults and many other species can be found
along roads, paths, and trails, on grass, and
on other low vegetation in a "waiting position."
As an animal passes by the tick will grasp it
firmly and soon start feeding on its host. The
males remain on the host for an indefinite
period of time alternately feeding and mating.
The females feed, mate, become engorged,
and then drop off to lay their eggs.
The American dog tick requires from 3 months
to 3 years to complete a life cycle It is typically
an outdoor tick and is dependent on climatic
and environmental conditions for its eggs to
hatch.
One Host Tick
Two Host Tick
Nasal bot - Oestrus ovis
• Description: Adult flies are _ to 5/8 inch
long, wide-bodied, mottled yellowish to
gray-brown, and quite hairy; mouthparts
are rudimentary. Larvae are grublike
maggots that reach one to one and onefourth inch in length.
• Domestic animals affected: sheep, goats.
• Damaged caused: extreme annoyance
during larviposition; later, during larval
development, a snotty and sometimes
bloody nasal discharge, loss of appetite,
vigorous head shaking, secondary infection
of the sinuses; sometimes death.
• Development: complete metamorphosis:
egg (hatches within female), larval stages,
pupa, adult fly.
• Generational time: typically one year, but
spring larviposition may result in a
complete developmental cycle that
produces adults within 10 to 12 weeks.
Nasal bot - Oestrus ovis
• Upon being deposited in the nostril of a sheep, the larva crawls
onto the mucous membrane of the nasal passage, where it will
remain for at least two weeks. Development of the 1st instar
larva may be delayed, and individuals from the same
larviposition may spend from 1 to 9 months in the 1st instar.
This plays a role in the overwintering cycle.The pupal stage
lasts 1-2 months depending upon temperature
Diagnosis of External Parasites
• Parasites or the signs associated with
infestations an be observed upon routine
examination of the animal.
Treatment/Prevention
•
Most external parasites are controlled on a flock/herd wide basis. This means that
when one animal is diagnosed with external parasites, a dip, dust, or spray is used to
treat the problem that animal as well as the entire flock/herd. The following table
outlines the common products and the treatments used to treat the external parasites
Active Ingredient
Effective Against
**Treatments
*Malathion
Mites, lice, keds
0.5% spray; 4% dust
*Lime-sulfur
Mites, lice, keds
2-5% dip
*Coumaphos
Mites, lice, keds
0.05-0.3% spray or dip; 0.5%-1% dust
*Phosmet
Mites, lice, keds
0.15-0.25% dip
*Methoxychlor
Mites, lice, keds,
ticks
0.5% spray or dip; 5% dust
* These products are not labeled for use in sheep and goats. Their use in these animals is considered "extra-label."
References
• www.Infovets.com
• Texas 4-H Goat Guide