Anoplocephala spp. (1)

Question 1

What are the intermediate hosts?

Answer 1

Oribatid mite

Question 2

Describe adults

Answer 2

4-80 cm long (depends on species)

Very short proglottids, wide

Anoplocephala perfoliata

 - More common
 - White
 - 4 cm
 - Lappets
 - Large
 - Round scolex with lappet behind each of 4 suckers

Anoplocephala magna

 - Larger
 - 80 cm
 - No lappets

Question 3

Describe the eggs

Answer 3

Triangular shape

50-80 micro m long

Irregular shape

Contain small embryo

Not always seen in fecal

Question 4

What is the larval form?

Answer 4

Cysticercoid

Question 5

Explain the life cycle

Answer 5

PPP: 4-6 weeks

Mature segments pass in feces, disintegrate and release eggs

Ingested by oribatid or forage mites - develop to cysticercoids

Infected mite eaten by horse while grazing
- Mites may be present in bedding, hay, grass

No seasonality

Question 6

What is the site of infection?

Answer 6

Adult A. perfoliata - ileocecal valve, cecum

Adult A. magna - Small intestine

Question 7

Describe the Pathogenesis

Answer 7

Heavy infections of A. perfoliata - ulcerations

 - Can lead to partial occlusion of ileocecal valve
 - Intussusception of terminal ileum and cecum 

Nonpathogenic

Large numbers

 - Ill health
 - Unthriftiness
 - Death

Question 8

How do you diagnose?

Answer 8

Egg detected with centrifugation and flotation

Sedimentation

Antigen ELISA

Question 9

How do you treat?

Answer 9

Praziquantel

Question 10

What are the final hosts?

Answer 10

Equine