Symptoms to Look for When Your Animal is Infested with Internal Parasites. Presentation given at Delaware Ag Week, 2024.

1. Show Me the Signs
Symptoms to Look for When Your Animal is Infested with Internal Parasites
SUSAN SCHOENIAN
Sheep & Goat Specialist Emeritus
University of Maryland Extension
sschoen@umd.edu

2. Small ruminants can be infected with many
different kinds of internal parasites. In fact,
they usually harbor MIXED infections.
Helminths “worm-like” parasites
1. Nematodes
Roundworms
Strongyles****
2. Cestodes
Flatworms - Tapeworms
3. Trematodes
Flukes
Single cell protozoa
1. Coccidia****
2. Giardia
3. Cryptosporidium

3. Nematodes - Roundworms
PRIMARY
1. Haemonchus contortus
Barber pole worm****
2. Teladorsagia circumcincta
Brown stomach worm
3. Trichostrongylus colubriformis
Bankrupt or black scour worm
SECONDARY – MUCH LESS IMPORTANT
• Cooper’s worm
Cooperia spp.
• Hookworms
Bunostonum phlebotomum
• Lungworms
Dictycaulus filaria
Muellerius capillaris
Protostrongyles reufescens
• Meningeal worm***
Parelaphostrongylus tenuis
• Nodule worm
Oesophagostumum spp.
• Thicknecked intestinal worm
Nematodirus spp.
• Threadworm
Strongyloides spp.
• Whipworm
Trichuris ovis

4. Haemonchus contortus
Barber pole worm
• Most common worm parasite affecting
small ruminants
• Also, most pathogenic
• Blood sucking parasite that lives and
develops in abomasum.
• Short, direct life cycle
• Ability to survive adverse weather by
going into arrested state (hypobiosis).
• Prolific egg layer
• Thrives in warm, moist weather.

5. Haemonchus contortus
Barber pole worm
DIAGNOSIS
• Clinical symptoms
• Fecal analysis
• Post-mortem
SYMPTOMS
• Can be acute or chronic
• Anemia: blood and protein loss
Pale gums and conjunctiva
FAMACHA© 3, 4, and 5
• “Bottle jaw” (not all animals)
Sub-mandibular edema
• Weakness and debilitation
• Loss of weight and body condition
• Death, sometimes sudden
• Not diarrhea (scours)

6. Trichostrongylus colubriformis
Bankrupt or black scour worm
• One of the three most common worm
parasites affecting small ruminants;
usually part of mixed infection.
• Invisible or small parasites of the small
intestines; difficult to see with naked
eye.
• Live and develop in small intestines.
• Not as prolific as barber pole worm
• Similar life cycle as barber pole worm

7. Trichostrongylus colubriformis
Bankrupt or black scour worm
DIAGNOSIS
• Clinical signs
• Fecal egg analysis
• Post mortem
SYMPTOMS
• Generally asymptomatic
• As part of mixed infections, contribute to symptoms of
animals with barber pole worm infections.
• Attach to the intestinal wall causing abrasion and
destruction.
• Damage the villi of the small intestines
• Reduced nutrient absorption has not been demonstrated
• Severe infections
• Reduced feed intake
• Reduced weight gain
• Reduced milk production
• Death is rare

8. Teladorsagia circumcincta
Brown stomach worm
• One of top-three worms affecting
small ruminants; usually part of
mixed infection.
• Small, reddish-brown worm
• Lives and develops in abomasum
• Not as prolific as barber pole
worm
• Short, direct life cycle
• Similar life cycle as barber pole
worm

9. Teladorsagia circumcincta
Brown stomach worm
DIAGNOSIS CLINICAL SIGNS
• As part of mixed infections,
contribute to symptoms of animals
with barber pole worm.
• Diarrhea (scours)
• Reduced appetite
• Reduced wool and milk production
• Reduced weight gains
• Emaciation
• Sometimes, death
• Clinical symptoms
• Fecal analysis
• Post-mortem

10. Other roundworms
• Hookworms
Bunostonum phlebotomum
• Cooper’s worm
Cooperia spp.
• Nodule worm
Oesophagostumum spp.
• Thicknecked intestinal worm
Nematodirus spp.
• Threadworm
Strongyloides spp.
• Whipworm
Trichuris ovis
https://www.wormx.info/otherworms

11. Other roundworms
• Usually, not very pathogenic
• Usually, part of mixed infections
• Usually, small numbers.
• Can worsen symptoms of animals infected
with other parasites (most likely scenario):
diarrhea and anemia.
• Rarely problems by themselves.
• Diagnosis by fecal analysis.
https://www.wormx.info/otherworms

12. Eimiera spp.
Coccidia
• Single-cell protozoan parasite
• Spread oral-fecal route
• Host-specific: not even sheep and
goats share same coccidia species.
• Not all species of coccidia cause
disease or are as pathogenic.
• Affects mostly young animals, 1-6
months of age.
• Adults mostly immune, but carriers.
• As important as barber pole worm.

13. Eimiera spp. Coccidia
SUB-CLINICAL
• Reduction in
productivity: feed
conversion and
growth
CLINICAL
• Diarrhea (scours)
from green and slimy to bloody
• Straining
(can lead to rectal prolapse)
• Dullness
• Anorexia
• Abdominal pain
• Rough hair coat
• Wasting: loss of weight and body condition
• Sometimes death
DIAGNOSIS
• History/signs/age
• Fecal oocyte analysis
• Post-mortem

14. Moniezia
expansa:
Tapeworms
• Flat, ribbon-like worm.
• Only worm visible in feces.
• Indirect life cycle; requires
intermediate host to complete its
life cycle (pasture mites).
• Immunity developed at early age.
• Adults mostly immune.
• Usually, non-pathogenic.
• Usually, no benefit to treatment.

15. Moniezia expansa: Tapeworms
Diagnosis
• Segments in manure and eggs in
fecal sample mean that animal is
infected, but not necessary that it
requires treatment.
Signs
• Usually, no signs – not even sub-clinical
Clinical
• Pot belly
• Dullness
• Poor growth
• Weight loss
• Diarrhea (scours)
• Colic
• Constipation
• Alter gut mobility and predispose lambs/kids to
enterotoxemia
• Intestinal blockages (death)

16. Parelaphostrongylus tenuis
Meningeal worm, deer
or brain worm
• Parasite of white tail deer.
• Sheep, goats, and camelids are
abnormal hosts
• Indirect life cycle; requires an
intermediate host to complete its
life cycle (snail or slug)
• Small ruminants ingest infective
third stage larvae.
• Mature larvae migrate out of the
stomach to spinal cord (CNS).

17. Parelaphostrongylus tenuis
Meningeal worm, deer or brain worm
DIAGNOSIS
• Fecal exam not useful; dead end host
• Cerebrospinal fluid collection
• Grazing history
• Physical signs
• Post-mortem
SYMPTOMS
• Signs depend on the number and location of
migrating larvae.
• Almost any central nervous system sign is
possible.
• Progressive posterior paralysis is most
common symptom.
• In goats, skin lesions that cause intense
rubbing and biting are common.

18. Lungworms: large and small
LARGE LUNGWORMS
Dictycaulus filaria
• Most pathogenic lungworm
• Different from one that infects cattle
• Not widespread problem in US.
SMALL LUNGWORMS
1. Muellerius capillaris
2. Protostrongyles reufescens
More pathogenic than M. capillaris, but
less than D. filaria
Indirect life cycles; require intermediate
host to complete life cycle (snail, slug).
More common in goats than sheep.
Differentiate species by larvae

19. Lungworms
DIAGNOSIS
• Difficult to diagnose by yourself
• Biosecurity
Can be introduced by other animals
Deer infected by same lungworms
Camelids can be infected by same lungworms
as sheep, goats, and cattle.
• Clinical signs: not every animal that coughs
or has a snotty nose has lungworms
Diagnostic testing (by veterinarian)
• Identify larvae in feces
• Worms found during autopsy
• Nodules on lungs
SYMPTOMS
• In most cases, no outward signs of disease.
• Sub-clinical: reduced milk production, lower
growth rates, and weight loss.
• Only in severe infections, do lungworms
cause disease
• Parasitic (verminous) pneumonia or bronchitis
• Coughing
•
Difficulty breathing
• Secondary bacteria could cause death

20. Fasciola hepatica, Fascioloides magna
Liver fluke
• Problematic in low, lying wet
areas.
• Not common to Mid-Atlantic.
• Indirect life cycle involving
snails.
• Immature flukes migrate
through the liver.
• Adult flukes reside in bile ducts
of the liver

21. Fasciola hepatica, Fascioloides magna
Liver fluke
DIAGNOSIS
• Clinical signs
• Finding eggs in the feces using
sedimentation technique.
• Blood samples
• Post-mortem
SYMPTOMS
• Can be acute, sub-acute, or chronic
• Unthriftiness
• Lethargy
• Weight loss
• Reduced gains
• Poor fleece quality
• Anemia
• Sometimes, bottle jaw
• Sometimes death

22. Using fecal
analysis to
identify
problems

23. Fecal analysis
ROUTINE FECAL ANALYSIS
1. Qualitative
Mix feces with flotation solution
What most veterinarians do (for dogs/cats)
Results are usually positive or negative
Sometimes use +++ signs to indicate
general level of infection.
2. Quantitative
Uses known amount of feces and flotation
solution.
Determines eggs per gram of feces (EPG).
Method, you need to use, whether you do it
yourself or have someone else do it.
LABORATORY TESTS
1. DrenchRite Larval Assay
Pool fecal sample
Determine fecal egg count
(Hatch eggs) - identifies species from larvae
Determine resistance to dewormers
2. Coproculture
Identifies species from larvae
3. Lectin staining
Determines portion of H. contortus eggs

24. Trichostrongylidae
family
1. Haemonchus contortus
Barber pole worm
2. Teladorsagia circumcincta
Brown stomach worm
3. Trichostrongylus colubriformis
Bankrupt or black scour worm
• Fecal egg counts are usually for strongyle-type worms.
• Results are often expressed as % H. contortus + %
Teladorsagia/Trichostrongylus.
• These eggs look similar and must be hatched in order to
accurate identify species (from larvae).
Three main worms
affecting small
ruminants.

25. Less
important
1. Hookworms (similar-looing to trichs)
Bunostonum phlebotomum
2. Cooper’s worm
Cooperia spp.
3. Nodule worm
Oesophagostumum spp.
4. Thicknecked intestinal worm
Nematodirus spp. (large egg)
5. Threadworm
Strongyloides spp.
6. Whipworm (football shaped)
Trichuris ovis
1
3
2
4
5
6

26. Other parasites
1. Tapeworms
Triangular-shaped eggs
Egg packets visible in feces
2. Meningeal worm
Dead end host – NO eggs in feces
Could test spinal fluid
3. Liver flukes
Use sedimentation technique
4. Lungworms
Identify first stage larvae instead of egg
Need to use Baermann technique
1
3
4

27. Eimeria spp. Coccidia
• Can use McMaster technique to
determine fecal oocyte count
(FOC). [small egg]
• Small ruminants can be infected
by many different species of
Eimeria.
• Small ruminants harbor their
own species of Eimeria and there
is no cross-infection.
• Not all strains of coccidia are
disease causing or equally
pathogenic (speciation
warranted).
• A FOC of 5000 with appropriate
signs may be noteworthy, if

28. Two primary parasite concerns
BARBER POLE WORM COCCIDIA

29. Questions?
Comments?
SUSAN SCHOENIAN
Sheep & Goat Specialist Emeritus
University of Maryland Extension
sschoen@umd.edu
www.wormx.info
www.sheepandgoat.com
www.sheep101.info
facebook.com/MDSmallRuminant/