Tapeworms of ruminants

Question 1

Which groups of worms do tapeworms belong to?

Answer 1

Platyhelminths - cestodes

Question 2

What are some of the general tapeworm characteristics?

Answer 2

• Adult worms are segmented
• Indirect life cycles – more than one host
• Flatworms
• Adult parasite in definitive host

Question 3

What is the name of the tapeworm when its in the intermediate host?

Answer 3

Metacestode - pathogenic

Question 4

What is the name of the tapeworm body wall?

Answer 4

Tegument

Question 5

Describe the head of a tapeworm

Answer 5

Scolex

• Can contain suckers or barbs
• This is the end of the tapeworm that attaches to the gut

Question 6

How do the segments of the tapeworm change as you move away from the head?

Answer 6

• The newly produced segments called proglottids are behind the head, they get bigger and more mature as you go down the worm

Question 7

What does every mature proglottid contain?

Answer 7

Female and male sex organs

Vitelline glands to produce the egg shell when they are fertilised

Question 8

How is nutrition taken into the tapeworms body?

Answer 8

Through the tegument

Question 9

Describe the general life cycle of a tapeworm

Answer 9

• Adults in small intestine
• Proglottids break off
• Eggs/proglottids shed in faeces
• Eggs immediately infective
• Eggs eaten by intermediate host
• Metacestode develops in intermediate host
• Metacestode eaten by definitive host

Question 10

Which type of metacestode goes on to become the head of the tapeworm?

Answer 10

Cysticercus

Question 11

Lots of different copies of the cysticercus which can all give rise to a tapeworm are called?

Answer 11

Coenurus

Question 12

Development of the Coenurus leads to which type of metacestode?

Answer 12

Hydatid

Question 13

When sheep are the intermediate host, what is the definitive host?

Answer 13

Dogs

Question 14

Which 4 metacestodes are found in dogs?

Answer 14

• Taenia ovis
• Taenia hyatigenia
• Taenia multiceps
• Echinococcus granulosus

Question 15

Which metacestode causes sheep measles?

Answer 15

Taenia ovis - cysticercus in muscles

Question 16

Which metacestode migrates through the liver in sheep?

Answer 16

Taenia hyatigenia

Question 17

What is the effect of Taenia multiceps?

Answer 17

• affects the brain of a sheep

- space occupying lesion

Question 18

Hydatid cysts in the liver and lungs of sheep are caused by which metacestode?

Answer 18

Echinococcus granulosus

Question 19

What can you use to treat adult dogs for tapeworm, what is the dosing interval?

Answer 19

Praziquantel - every 6 weeks

Question 20

When cattle and pigs are the intermediate host, what species is the definitive host?

Answer 20

Humans

Question 21

Name the beef tapeworm metacestode

Answer 21

Taenia saginata

Question 22

Where is the metacestode of cattle tapeworm found?

Answer 22

In muscles

Question 23

Name the pork tapeworm metacestode

Answer 23

Taenia solium

Question 24

Human cysticercosis has what clinical signs/side effects?

Answer 24

Epilepsy, headaches, sub-cutaneous lumps, neuro and ocular cysticercosis

Question 25

Name the long adult tapeworm found in sheep and cattle

Answer 25

Monezia spp

Question 26

Describe the life cycle of Monezia spp

Answer 26

- Metacestode stage (cysticercoid) develops in oribatid mite intermediate host - The whole mite gets ingested when the sheep and cattle graze - Lives in the SI

Question 27

You find a bunch of fluid filled cysts in the peritoneum associated with the liver of a sheep at the abattoir, what are they likely to be?

Answer 27

Taenia hydatigena

Question 28

``` During meat inspection, you find a 1cm diameter cyst in (a) leg muscles of a sheep (b) the masseter muscles of a cow (c) lungs of a lamb. What are they most likely to be? ```

Answer 28

(a) Taenia ovis (b) Taenia saginata (c) Echinococcus granulosus

Question 29

How are sheep infected with T. hydatigena and T. ovis?

Answer 29

Through ingesting eggs shed in dog faeces (dogs are the definitive host, harbour the adult tapeworm, metacestodes found in sheep).

Question 30

An egg of 60um and another egg of 40um are found, which species do each most likely belong to?

Answer 30

``` 60 = Monezia spp, adult tapeworms in the gut of sheep 40 = Taenia spp. or Echinococcus eggs found in faeces of dogs ```

Question 31

How would you differentiate between L1 larvae of Muellerius capillaris and Dictyocaulus filaria in faeces of a sheep?

Answer 31

Df L1 has a cuticular knob on the anterior end. Mc has a spike on the tail.