Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Parasitology > Lecture 17 Large and small strongyles of horses > Flashcards

Lecture 17 Large and small strongyles of horses Flashcards

1
Q

what is the usual site for superfamily Strongyloidea

A

large intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

3 features of strongyloidea

A
  • bursa in male
  • large buccal capsule
  • leaf crown
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are the hosts of strongyloidea

A

horses
pigs
ruminants
birds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is the lifecycle of strongyloidea

A 
L1-(L3) -- in faeces
(L3) on -- herbage
L3 migrates -- into int. gland
L4 emerges -- to lumen
final moult in lumen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

can strongyloidea do extra migration and how would this effect the PPP

A

yes, makes PPP longer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what subfamily is known as large strongyles that infect horses

A

strongylinae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what characterizes large strongyles of horses

A

large, globular buccal capsule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the two most important genera of large stongyles in horses

A

strongylus

tridontophorus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What species of Strongylus are there including the one that is not in Australia
what is this generas common name

A 
S. vulgaris
S. edentatus
S. equinus
S. asini (donkey, zebra- not in aus)
- common name- red worms or blood worms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where are large strongyles of horses located?

A

cecum and colon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the life cycle of the large strongyle in horses

A

Eggs passed out in feces

  • eggs in feces develop into L1, L2, L3 stage larvae
  • L3 move to the grass
  • L3 ingested
  • L3 penetrates intestinal wall->abdomen at L4->back into intestine
  • L4->adult and lays eggs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What problems can L4 of large strongyles in horses cause when they are migrating in the abdomen

A

can cause colic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is an identifying factor of Strongylus vulgaris and is it a large or small strongyle

A

two dorsal lobed or ear shaped teeth

large strongyle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the life cycle of Strongylus vulgaris? direct or indirect?

A

• L1 and L2 develop in faeces, feed on bacteria
• development to L3 stops below 8oC
• L3 exsheaths (L2 sheath) in small/large intestine
• migrates into intestinal wall
• migrates in wall of arteries and ascends
to root of cranial mesenteric arteries
• remains for several weeks
• returns to gut in blood stream
• enters lumen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what is the PPP for strongylus vulgaris

A

6 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what do adult strongylus vulgaris feed on

A

mucosa of gut and blood

1 female can ingest 10ml of blood an hour

17
Q

What are 3 effects that strongylus vulgaris have on the horse host?

A
  • Migration within arteries damages intima-> thrombi.
  • Inflammation in walls of vessels-> deposition of fibrous tissue, thickening of
    vessel walls and narrowing of lumen.
  • verminous arteritis
  • Thrombi may occlude vessels, cause intermittent colic or severe ischaemia leading
    to infarction and gangrene.
  • Adults can cause anaemia, elevated white cell count, eosinophilia.
18
Q

3 points of epidemiology of strongylus vulgaris of the horse

A
  • prevalence in Victoria has been reduced (85->25%)
  • Larvae most abundant in spring killed in summer, winter stops development
  • peak egg laying 10 mo after infection
  • foals develop immunity
19
Q

What are 3 features of Strongylus edentatus

A
  • buccal capsule is wider anteriorly than posteriorly
  • no teeth in buccal capsule
  • very common species
  • larger than S. vulgaris (2.3-4.4 cm)
20
Q

what is the life cycle of strongylus edentatus

A
  • L3 exsheaths in caecum
  • burrows into gut wall
  • enters portal veins
  • migrates to liver
  • spends 8 weeks in liver
  • migrates to sub-peritoneal tissues
  • returns to gut via mesentery
21
Q

how long is the PPP for strongylus edentatus

A

10 months

22
Q

what is the effect on the horse host of strongylus edentatus

A
  • Aberrant larvae found in kidney, lung, testes.
    • migrating larvae cause lesions
  • feed on blood
    • adults cause anaemia (normocytic normochromic)
23
Q

What are 3 features of strongylus equinus and is it a small or large strongyle

A

• 3 teeth in buccal capsule
• deepest buccal capsule
• tropical species- low prevalence in australia
-large strongyle

24
Q

what is the life cycle of strongylus equinus

and what is the effect on the horse host?

A 
• L3 exsheaths in caecum
• L3 migrates into gut wall,
• peritoneal cavity & liver
• spends 6-7 weeks in liver
• migrates via pancreas to gut
- anemia
25
Q

what is the PPP of strongylus equinus and what do the adults feed on (think of strongylus common name)

A

8 months

blood- common name is red or blood worms

26
Q

what is another important genera in the subfamily stongylinae (large strongyles) other than strongylus
what is the main feature of this genera

A

triodontophorus
3 teeth

also oesophagus and craterostomum

27
Q

what is the lifecycle of triodontophorus

A 
• L3 exsheaths in caecum
• L3 migrates into gland
• moults to L4
• L4 emerges into lumen
• final moult in lumen
NO EXTRA INTESTINAL MIGRATION
28
Q

Because triodontophorus has no extra intestinal migration what is the PPP

A

9 weeks

shorter than strongylus that has extra intestinal migration

29
Q

what is the effect of tridontophorus on the horse host and is it a large or small strongyle

A

• graze on epithelial lining of gut
• occur in groups
• cause ulceration & blood loss
- large strongyle

30
Q

what subfamily is considered the small strongyles of horses

A

cyathostominae

31
Q

what is characteristic of cyathostominae

A

all have cylindrical buccal capsule (not globular like large)
occur in large numbers (15000) but won’t show symptoms until 1-200000

32
Q

what is the lifecycle of the genus cyathostomum

A 
• L3 exsheath in caecum
• enters caecal glands
• moults to L4
• L4 re-emerges to lumen
• final moult in lumen
-no extra intestinal migration
33
Q

what is the PPP of cyathostomum and is hypobiosis important

A

5 weeks minimum

yes hypobiosis is important- seasonal pattern and if adults are removed emergence may be synchronus

34
Q

at what stage and where would hypobiosis occur in cyathostomum (small strongyle of horse)

A

stage L4 in the intestinal mucosa

risk of damage if high number of encysted L4 emerge from hypobiosis at the same time

35
Q

what is the effect on the host of cyathostomum

A
  • adults feed on gut content
  • not pathogenic
  • very large numbers (1x106) cause diarrhoea
  • normally 115,000 larvae encysted
  • visible from external surface
  • massive emergence causes severe diarrhoea
36
Q

how could you diagnose cyathostomum

A
  • find eggs in faeces
  • use McMaster chamber
  • > 300 epg pathogenic
  • larval culture to identify genera

Parasitology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions