Non Bursate Nematodes

Question 1

List the superfamilies of non bursate nematodes

Answer 1

Rhabditoidea (threadworms)
Ascaridoidea (round worms)
Oxyuroidea (pin worms)
Habronematoidea ( tight spiral tail things)
Filaroidea (worms in circulatory system)
Trichinelloidea (L1 infective stage)

Question 2

Rhabditoidea

Answer 2

strongyloides (threadworms)
only females are parasite
5-6mn
in SI villi
significant in very young horses, pigs and ruminants

Question 3

Ascardoidea

Answer 3

round worms
in SI
Thick and sticky eggs –> persist in the environment
L3 develops in egg
pathogenesis = ill thrift (slowing growth rate), diarrhoea, respiratory signs from migrating larvae.
can be zoonotic, when embryonic eggs ingested (ocular larva migrans or visceral larvae migrans

Question 4

Oxyuroidea

Answer 4

pin worms; blunt anteriorly, sharp posteriorly
Large intestines
direct life cycle
host specific

Question 5

Habronematoidea

Answer 5

Indirect lifecycle –> arthropod hosts

Males have tight spirally coiled tail

Question 6

Filaroidea

Answer 6

Adults in circulatory system or CTs, mircofilariae taken up by parasite insects
adult makes have loose spiral tail

Question 7

Trichinelloidea

Answer 7

has the whip worm
L1 infectious stage (different to others)
Stichosome or trichuroid oesophagus

Question 8

List the species of Rhabitoidea

Answer 8

Strongyloides ransomi (pig)
Strongyloides Westeri (horse, foals)

Question 9

List Ascaridoidea species

Answer 9

Toxocara canis (dog)
Toxocara cati
Parascaris equonum
Ascaris suum

Question 10

List the species of Oxyuroidea

Answer 10

Oxyuris equi

Enterobius vermicularis

Question 11

List species of Habronematoidea

Answer 11

Draschia Megastoma

Habronema species

Question 12

list species of Filaroidea

Answer 12

Dirofilaria Immitis (canine heartworm)
Dipetalonema reconditi
Onchocerca spp

Question 13

list species of Trichinelloidea

Answer 13

trichuris spp (whip worms)

Question 14

Strongyloides ransomi

Answer 14

pig thread worm
Rhabitoidea
larvae transferred w/colostrum
piglets infected within 24hrs of birth (severe loss)
intestinal disease 2-4wks after infection
good husbandry reduced in clean piggeries

Question 15

Strongyloides Westeri

Answer 15

horse and foal
Rhabitoidea
homogonic stage - pathogenic females in inestine
eaten or penetrate skin

Question 16

Toxocara canis

Answer 16

Dog round worm
Ascardoidea
ILL thrift, vomiting, diarrhoea, intestinal obstructions
pot belly puppies
10-18cm

Question 17

Toxocara cati

Answer 17

Cat roundworm
Ascardoidea
3-10cm

Question 18

parascaris equonum

Answer 18

15-50cm horse round worm

Ascardoidea

Question 19

Ascaris suun

Answer 19

• 20-40cm
  adults in SI
  tracheal migration after eggs ingested
  ascardoidea

Question 20

Oxyuris equi

Answer 20

horse pinworms
oxyuroidea
itching and irritation around anus, eggs laid around the anus

Question 21

Enterobius vermicularis

Answer 21

human pin worms

Oxyuroidea

Question 22

Drachia megastoma

Answer 22

horse
habronematoidea ( has an indirect lifecycle with arthropods)
in colonies within nodes in wall of equine stomach

Question 23

Dirofilaria immits

Answer 23

Canine heart worm
Filaroidea
- adults in pulmonary arteries
12-30cm
congestive heart failure, pneumonitis, renal disease
low worm burdens = no circulating micofilariae can complicate diagnosis

Question 24

Dipetalonema reconditum

Answer 24

Filaroidea in dogs
Adults in body cavity CT or kidneys
not clinically significant

Question 25

Onchocerca spp

Answer 25

cattle and horses
adults in CT, often in nodes
micofilariae in skin
midges - intermediate host
allergic skin reactions in horses, condemnation of carcasses

Question 26

Explain Trichuris

Answer 26

SF Trichinelloidea
whipworms
adults in LI/caecum of dog, pig, ruminants, people
long anterior, short. broader posterior
direct life cycle
Large burden can produce Large intestinal diarrhoea

Question 27

Rhabditoidea general lige cycle

Answer 27

Egg in faeces 
L1 -L2 free living
L3 skin penetration, ingestion (enters blood)
L4 tracheal migration
adult in SI

Question 28

Toxocara canis life cycle

Answer 28

Question 29

Habronema life cycle

Answer 29

Eggs in faeces
L1 eaten by maggots
L3 emerges from fly mouth, goes onto host lips
L4
Adults ingested

Question 30

Dirofilaria immures life cycle

Answer 30

Adult in the heart
produce offspring after 3-4 months
in 6-7mths it develops into microfilariae ( ingested by mosquito)
penetrate bite wound into CT
3-4 days = L4 in CT
2-3 months = adult in the heart