This document provides information on tapeworms (cestodes) that infect poultry and other animals. It describes the general characteristics of tapeworms, including their ribbon-like shape and life cycles. Specific information is given on several important tapeworm genera and species that infect poultry (Raillietina, Davainea), dogs (Dipylidium caninum), and horses (Anoplocephala, Moniezia). Key details are provided on the morphology, life cycles, and pathogenesis of these tapeworms. The document also discusses the taeniid tapeworms of humans (Taenia saginata, T. solium) and compares aspects of their morphology and life cycles.

1. VETERINARYVETERINARY
HELMINTHOLOGYHELMINTHOLOGY

2. TAPEWORM/ CESTODESTAPEWORM/ CESTODES
General Characteristics:General Characteristics:
1. ribbon-like and dorsoventrally flattened1. ribbon-like and dorsoventrally flattened
2. most of the show indirect types of life cycle. The exceptional type of2. most of the show indirect types of life cycle. The exceptional type of
life cycle is found inlife cycle is found in Hymenolepis sppHymenolepis spp where direct and indirectwhere direct and indirect
types are found.types are found.
3. they are hermaphrodite3. they are hermaphrodite
4. cysts or bladderworms are intermediate or larval stage of the4. cysts or bladderworms are intermediate or larval stage of the
parasiteparasite
5. the final host gets infection by ingestion of intermediate host or flesh5. the final host gets infection by ingestion of intermediate host or flesh
of intermediate host containing the bladder wormsof intermediate host containing the bladder worms
6. the body can be divided into three broad parts6. the body can be divided into three broad parts

3. Head/ ScolexHead/ Scolex
-very minute as compared to other parts-very minute as compared to other parts
-shape varies which may be roughly triangular,ball shaped or round-shape varies which may be roughly triangular,ball shaped or round
-there is presence of sucker (armed or unarmed ) which is not used-there is presence of sucker (armed or unarmed ) which is not used
for taking food but used as apertures for attachmentfor taking food but used as apertures for attachment
-anteriorly there is structure called rostellum-anteriorly there is structure called rostellum
NeckNeck
-immediately behind the head and without any segment-immediately behind the head and without any segment
-segmentation starts here-segmentation starts here
BodyBody
-area is completely segmented-area is completely segmented

4. Three types of segments are present:Three types of segments are present:
IMMATURE- the reproductive system and eggs are absentIMMATURE- the reproductive system and eggs are absent
MATURE- completely developed reproductive systemMATURE- completely developed reproductive system
GRAVID- reproductive system is replaced by the eggsGRAVID- reproductive system is replaced by the eggs
- either detached from the parasite or its disintegrated and- either detached from the parasite or its disintegrated and
the eggs are expelled outthe eggs are expelled out
Eggs:Eggs:
-have basic structure comprising oncosphere or hexacanth embryo,-have basic structure comprising oncosphere or hexacanth embryo,
a striated shell or embryophore and a delicate membranea striated shell or embryophore and a delicate membrane
-the following are the events which occur during biological-the following are the events which occur during biological
development:development:
a. Eggs are expelled out from the gravid segmenta. Eggs are expelled out from the gravid segment
b. the eggs are ingested by the intermediate hosts and hatchingb. the eggs are ingested by the intermediate hosts and hatching
occurs in the intermediate host or hatch in the environmentoccurs in the intermediate host or hatch in the environment
( Cotyloda)( Cotyloda)

5. -metacestodes / bladderworms / cyst / larval stages are formed in the-metacestodes / bladderworms / cyst / larval stages are formed in the
intermediate hostintermediate host
-final host gets the infection by ingestion of the intermediate host or the-final host gets the infection by ingestion of the intermediate host or the
muscles and flesh containing the cysts or bladderwormsmuscles and flesh containing the cysts or bladderworms

6. Poultry TapewormPoultry Tapeworm
Genus RaillietinaGenus Raillietina
--small to medium-sized tapeworm that inhabit the small intestinesmall to medium-sized tapeworm that inhabit the small intestine
-cosmopolitan in distribution-cosmopolitan in distribution
Species:Species:
R. cesticillus R. demerariensisR. cesticillus R. demerariensis
R. echidnobothridaR. echidnobothrida
R. tetragonaR. tetragona
R. asiaticaR. asiatica
R. celebensisR. celebensis

7. R. cesticillusR. cesticillus
Morphology:Morphology:
1. smaller (4-15 cm) than R. tetragona, R. echidnobothrida1. smaller (4-15 cm) than R. tetragona, R. echidnobothrida
2. broad rostellum which is armed with 400-500 hooks2. broad rostellum which is armed with 400-500 hooks
3. circular sucker is unarmed3. circular sucker is unarmed
4. egg capsule contains single egg4. egg capsule contains single egg
R. echidnobothridaR. echidnobothrida
MorphologyMorphology
1. size is 8.5-22 cm1. size is 8.5-22 cm
2. suckers are circular and surrounded by several rows of hooks2. suckers are circular and surrounded by several rows of hooks
3. rostellum is very small3. rostellum is very small
4. egg capsule contains multiple eggs4. egg capsule contains multiple eggs

8. R. tetragonaR. tetragona
1. 25 cm long and largest tapeworm in poultry1. 25 cm long and largest tapeworm in poultry
2. rostellum is small and possesses one or two rows of hooks2. rostellum is small and possesses one or two rows of hooks
3. egg capsule contains multiple eggs3. egg capsule contains multiple eggs
4. sucker is oval and surrounded by several rows of hooks4. sucker is oval and surrounded by several rows of hooks
LIFE CYLCE:LIFE CYLCE:
eggegg
oncosphereoncosphere
cysticercoid ( infective stage )cysticercoid ( infective stage )
adultadult
Ants and Musca domestica acts as IH of R. tetragona and R.Ants and Musca domestica acts as IH of R. tetragona and R.
echidnobothrida. The beetle acts as IH for R. cesticillusechidnobothrida. The beetle acts as IH for R. cesticillus

9. Pathogenesis:Pathogenesis:
1. nodule formation in the intestine by R. echidnobothrida1. nodule formation in the intestine by R. echidnobothrida
2. enteritis by R. tetragona and R. cesticillus2. enteritis by R. tetragona and R. cesticillus
Genus DavaineaGenus Davainea
D. proglottinaD. proglottina
D. meleagridisD. meleagridis
MorphologyMorphology
1. very small only several mm that’s why it is advised to take1. very small only several mm that’s why it is advised to take
mucosal scraping for its detectionmucosal scraping for its detection
2. has prominent rostellum armed with hammer-shaped hooks2. has prominent rostellum armed with hammer-shaped hooks
3. presence of single set of reproductive organ which alternates3. presence of single set of reproductive organ which alternates
regularlyregularly
4. has 4-9 segments4. has 4-9 segments
5. egg capsule contains single egg5. egg capsule contains single egg

10. Life cycle:Life cycle:
EggEgg
OncosphereOncosphere
Cysticercoid in IH ( infective stage on ants or slugs )Cysticercoid in IH ( infective stage on ants or slugs )
AdultAdult
The gravid segments crawl out of the host. The gravidThe gravid segments crawl out of the host. The gravid
segments are actively motile and crawl onto the grass blade due tosegments are actively motile and crawl onto the grass blade due to
its phototactic nature. The eggs are released during the act ofits phototactic nature. The eggs are released during the act of
crawling. The eggs hatch after ingested by IH and cysticercoid iscrawling. The eggs hatch after ingested by IH and cysticercoid is
formed within a month. The final host gets the infection when theformed within a month. The final host gets the infection when the
infected snails are ingested by the birds.infected snails are ingested by the birds.

11. Family Dipyliidae:Family Dipyliidae:
Dipylidium caninum- double pored tapeworm of dogsDipylidium caninum- double pored tapeworm of dogs
Morphology:Morphology:
1. head or scolex is pyriform in shaped having hooks characteristically1. head or scolex is pyriform in shaped having hooks characteristically
rose-thorn shapedrose-thorn shaped
2. presence of two sets of reproductive system like Moniezia spp2. presence of two sets of reproductive system like Moniezia spp
3. mature segments are cucumber seed shape3. mature segments are cucumber seed shape
LIFE CYCLE:LIFE CYCLE:
eggegg
onchosphereonchosphere
cystercercoid in IH ( flea C. canis, C. felis, T. canis, Pulex spp )cystercercoid in IH ( flea C. canis, C. felis, T. canis, Pulex spp )
adultadult

12. Gravid segments get detached from the adult tapeworm and crawl.Gravid segments get detached from the adult tapeworm and crawl.
During crawling the eggs are released from the gravid segment. TheDuring crawling the eggs are released from the gravid segment. The
IH ingest the eggs and hatched in the gut and oncospheres areIH ingest the eggs and hatched in the gut and oncospheres are
released and these migrate in the body cavity. A cysticercoid withreleased and these migrate in the body cavity. A cysticercoid with
tail appendage is formed within few weeks. Final host gets thetail appendage is formed within few weeks. Final host gets the
infection by ingestion of the infected IH.infection by ingestion of the infected IH.
Pathogenesis:Pathogenesis:
1. sloughing, denudation of mucosa1. sloughing, denudation of mucosa
2. constant irritation of the anal sac resulting to anal pruritus2. constant irritation of the anal sac resulting to anal pruritus
3. intoxication due to absorption of the metabolites released by the3. intoxication due to absorption of the metabolites released by the
parasites which affects the nervous systemparasites which affects the nervous system
Diagnosis:Diagnosis:
1. examination of fecal sample1. examination of fecal sample
2. dragging anus over the ground or any hard objects2. dragging anus over the ground or any hard objects

13. Family Anoplocephalidae: common cestodes of equineFamily Anoplocephalidae: common cestodes of equine
Morphology:Morphology:
1. rostellum and hooks are present1. rostellum and hooks are present
2. segments are noticeably broad2. segments are noticeably broad
3. presence of egg capsule or paruterine organ3. presence of egg capsule or paruterine organ
4. eggs have 3 coverings; the outermost formed by the vitelline gland,4. eggs have 3 coverings; the outermost formed by the vitelline gland,
middle albuminous and inner chitinousmiddle albuminous and inner chitinous
5. eggs of many members bear a pear shaped structure called5. eggs of many members bear a pear shaped structure called
pyriform apparatuspyriform apparatus
Genera:Genera:
Anoplocephala MonieziaAnoplocephala Moniezia
Paranocephala CittotaeniaParanocephala Cittotaenia
PseudanocephalaPseudanocephala

14. Imporant species:Imporant species:
AnoplocephalaAnoplocephala
magnamagna
AnoplocephalaAnoplocephala
perfoliataperfoliata
PseudoanoplocephalPseudoanoplocephal
a mamillanaa mamillana
1. Largest cestode1. Largest cestode
found in the horsefound in the horse
found in SI andfound in SI and
stomachstomach
Small intestineSmall intestine Si and stomachSi and stomach
2. 80 cm long2. 80 cm long 1-8 cm1-8 cm 0.6- 5 cm0.6- 5 cm
3. Testes are3. Testes are
arranged in rows.arranged in rows.
The number of testesThe number of testes
are 400-500are 400-500
250250 100100
4. Pyriform apparatus4. Pyriform apparatus
is not strong andis not strong and
largelarge
Large and strongLarge and strong Large and srongLarge and srong
Lappets are absentLappets are absent presentpresent absentabsent

15. LIFE CYCLE:LIFE CYCLE:
EggEgg
OnchosphereOnchosphere
Cysticercoid in IH ( mite)Cysticercoid in IH ( mite)
AdultAdult
Pathogenesis:Pathogenesis:
A. perfoliata particularly affects the ileocecal orifices and theyA. perfoliata particularly affects the ileocecal orifices and they
produce depressed ulcers which is dasrk in color and may causeproduce depressed ulcers which is dasrk in color and may cause
perforation of SIperforation of SI
A. magna causes hemorrhagic enteritis obstruction of the intestinalA. magna causes hemorrhagic enteritis obstruction of the intestinal
lumenlumen
P. mamillana less significantP. mamillana less significant

16. Family HymenolepididaeFamily Hymenolepididae
H. cariocaH. carioca H. diminutaH. diminuta H. nanaH. nana
dwarf tapewormdwarf tapeworm
1. 3-8 cm1. 3-8 cm 2-6 cm2-6 cm 7-80 cm7-80 cm
2. 500 segments2. 500 segments 500 segments500 segments Few segmentsFew segments
3. testes lie across3. testes lie across
the segmentthe segment
Testes are ovoidTestes are ovoid Testes lie in line andTestes lie in line and
separated by theseparated by the
ovaryovary

17. LIFE CYCLE:LIFE CYCLE:
eggegg
onchosphereonchosphere
cysticercoid in IHcysticercoid in IH
adultadult
Family TaeniidaeFamily Taeniidae
MorphologyMorphology
1. large tapeworm1. large tapeworm
2. proglottids are rectangular2. proglottids are rectangular
3. rostellum may or may not be present3. rostellum may or may not be present
4. segments are longer and broader4. segments are longer and broader
5. uterus has median stem and lateral branches5. uterus has median stem and lateral branches
6. egg capsule is easily lost and the embryo pore is striated in appearnace6. egg capsule is easily lost and the embryo pore is striated in appearnace

18. Intermediate StageIntermediate Stage Intermediate hostIntermediate host
Taenia soliumTaenia solium Cysticercus cellulosaeCysticercus cellulosae pigpig
Taenia saginataTaenia saginata Cysticercus bovisCysticercus bovis cattlecattle
Taenia hydatigenaTaenia hydatigena Cysticercus tenuicollisCysticercus tenuicollis Sheep, ruminantsSheep, ruminants
Taenia pisiformisTaenia pisiformis Cysticercus pisiformisCysticercus pisiformis rabbitsrabbits
Taenia taeniaformisTaenia taeniaformis Cysticercus fasciolarisCysticercus fasciolaris rodentsrodents
Taenia multicepsTaenia multiceps Coenurus cerebralisCoenurus cerebralis Sheep And goatSheep And goat

19. Taenia saginataTaenia saginata Taenia soliumTaenia solium
Host is manHost is man manman
Rostellum is absentRostellum is absent Present armed with hooksPresent armed with hooks
1000-2000 segments1000-2000 segments 800- 1000 segments800- 1000 segments
Ovary is bilobedOvary is bilobed trilobedtrilobed
Oval eggOval egg SphericalSpherical
Uterus has 14-32 branchesUterus has 14-32 branches 16 branches16 branches

20. Taenia soliumTaenia solium
Life cycle:Life cycle:
egg ( hatch after being ingested)egg ( hatch after being ingested)
Onchosphere ( migrates in different organs and tissues)Onchosphere ( migrates in different organs and tissues)
Cysticercus ( infective stage in the pork )Cysticercus ( infective stage in the pork )
Adult ( ingestion of infected ham and pork )Adult ( ingestion of infected ham and pork )
Man gets infection by the ff: waysMan gets infection by the ff: ways
1. ingestion of pork containing cysticercus1. ingestion of pork containing cysticercus
2. ingestion of eggs through the food and cysticercus develops in man2. ingestion of eggs through the food and cysticercus develops in man
3. by autoinfection due to retrosperistaltic movement. The eggs return to the stomach3. by autoinfection due to retrosperistaltic movement. The eggs return to the stomach
and hatchand hatch
Predisposing factors:Predisposing factors:
1. eating habits of people1. eating habits of people
2. large scale implementation of insewcticide2. large scale implementation of insewcticide

21. Pathogenesis:Pathogenesis:
ManMan
1. utilize the nutrition of the host1. utilize the nutrition of the host
2. causes enteritis2. causes enteritis
3. neurocysticercosis3. neurocysticercosis
PigPig
1. measly pork- presence of cysticerci in different organs or tissue1. measly pork- presence of cysticerci in different organs or tissue
Clinical signs:Clinical signs:
Man NeurocysticercosisMan Neurocysticercosis
1. diarrhea 1. encephalitis and meningitis1. diarrhea 1. encephalitis and meningitis
2. abdominal pain 2. epileptic fit and excitement2. abdominal pain 2. epileptic fit and excitement
3. vomiting3. vomiting
4. flatulence4. flatulence

22. Taenia multicepsTaenia multiceps
Life cycle:Life cycle:
eggegg
OnchosphereOnchosphere
Coenurus ( infective stage in the brain of sheep and goat )Coenurus ( infective stage in the brain of sheep and goat )
AdultAdult
Pathogenesis:Pathogenesis:
1.1. Migratory onchospheres care dangerous in the sheep. This causesMigratory onchospheres care dangerous in the sheep. This causes
meningitis and encephalitismeningitis and encephalitis
2.2. Gradually the cyst creates pressure in the brain as per theGradually the cyst creates pressure in the brain as per the
advancement of development of cyst. The brain muscles getadvancement of development of cyst. The brain muscles get
atrophiedatrophied
3.3. The skull gets atrophied and ultimately maybe soft and easily feltThe skull gets atrophied and ultimately maybe soft and easily felt
when touchingwhen touching
4.4. Aside from brain several nerves are also affected ( ocular,Aside from brain several nerves are also affected ( ocular,
auditory )auditory )

23. Clinical signs:Clinical signs:
1. the animal looses the condition and fails to respond to the1. the animal looses the condition and fails to respond to the
environmentenvironment
2. circling movement ( gid ) is an important sign2. circling movement ( gid ) is an important sign
3. sometimes the animals move in straight and keep its head on the3. sometimes the animals move in straight and keep its head on the
hard surfacehard surface
Genus EchinicoccusGenus Echinicoccus
E. granulosusE. granulosus
E.E. vogelivogeli
E. multilocularisE. multilocularis
E. oligarthusE. oligarthus
Morphology:Morphology:
1. very small only few segments are present1. very small only few segments are present
2. terminal segment is the gravid segment2. terminal segment is the gravid segment
3. scolex has the rostellum which is armed with hooks3. scolex has the rostellum which is armed with hooks
4. ovary is kidney shaped4. ovary is kidney shaped

24. Life cycle:Life cycle:
eggegg
onchosphereonchosphere
hydatid cyst in IHhydatid cyst in IH
adultadult
Pathogenesis:Pathogenesis:
1. enteritis1. enteritis
2. pressure atrophy in the vital organs due to pressure of large-2. pressure atrophy in the vital organs due to pressure of large-
sized cystsized cyst
3. functional disturbance3. functional disturbance
Diagnosis:Diagnosis:
1. examination of feces1. examination of feces
2. detection of cysticercus in the tongue and other palpable areas2. detection of cysticercus in the tongue and other palpable areas
3. Casonis Test- hydatid fluid is inoculated in the suspected3. Casonis Test- hydatid fluid is inoculated in the suspected
individual and there would be hypersensitive reaction within 15 minsindividual and there would be hypersensitive reaction within 15 mins
or less in positive casesor less in positive cases

25. Family Mesocestoididae:Family Mesocestoididae:
Genus MesocestoidesGenus Mesocestoides
M. lineatus M. jonesiM. lineatus M. jonesi
M. variabilisM. variabilis
M. tenuisM. tenuis
Morphology:Morphology:
1. head or scolex is devoid of rostellum and hooks1. head or scolex is devoid of rostellum and hooks
2. presence of single set of reproductive system2. presence of single set of reproductive system
3. genital pore is dorsally situated3. genital pore is dorsally situated
4. bilobed ovary and vitelline glands4. bilobed ovary and vitelline glands
5. testes are situated on either side of the excretory canal5. testes are situated on either side of the excretory canal
DH- dog, fox, catDH- dog, fox, cat
IH- 1IH- 1stst
– mites– mites
22ndnd
- birds- birds

26. Developmental stages:Developmental stages:
eggegg
onchosphereonchosphere
cysticercoid in IHcysticercoid in IH
tetrathyridium in birds, lizards, snakestetrathyridium in birds, lizards, snakes
adultadult
*M. corti can asexually multiply in the IH and DH*M. corti can asexually multiply in the IH and DH
Pathogenesis:Pathogenesis:
1. enteritis1. enteritis
2. nervous disorder2. nervous disorder
3. anal priritus3. anal priritus

27. Genus DiphyllobothriumGenus Diphyllobothrium
Species:Species:
D. latumD. latum
D. mansonoidesD. mansonoides
Morphology:Morphology:
1. long and maybe reaching up to several meters1. long and maybe reaching up to several meters
2. thousands of segments are presents2. thousands of segments are presents
3. head is spatula shaped with a deep groove in the middle called3. head is spatula shaped with a deep groove in the middle called
bothriabothria
4. no rostellum4. no rostellum
5. genital organs are situated mid-ventrally5. genital organs are situated mid-ventrally
6. eggs are oval and operculated and have fair resemblance to6. eggs are oval and operculated and have fair resemblance to
trematodestrematodes
7. ovary is bilobed and uterus is rosette-shaped7. ovary is bilobed and uterus is rosette-shaped

28. Life cycle:Life cycle:
EggEgg
Ciliated coracidiumCiliated coracidium
Procercoid (cyclops)Procercoid (cyclops)
Plerocercoid (fish)Plerocercoid (fish)
AdultAdult
PathogenesisPathogenesis
1. enteritis1. enteritis
2. anemia ( B12 def. or Pernicious anemia )2. anemia ( B12 def. or Pernicious anemia )
3. anal pruritus3. anal pruritus
4. epileptic fit4. epileptic fit