Brainscape's Knowledge GenomeTM

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


See full index

serpent taming > Strongyles 2 > Flashcards

Strongyles 2 Flashcards

1
Q

You find strongyle-type eggs in a foal less than 6 weeks old. What do you suspect?

A

The foal probably swallowed ingested mare feces, and the eggs are just passing through the GI tract.

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

You find strongyle-type eggs in a foal >6wks but <6mo old. What do you suspect?

A

Likely a small strongyle infection.

Recall that the minimum pre-patent period for large strongyles is 6 months.

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

You find strongyle-type eggs in a foal older than 6 months. What type of infection do you suspect?

A

Probably a mixture of large and small strongyles.

Impossible to differentiate between large and small strongyle eggs grossly. To distinguish the two, you can allow the larvae to hatch or run a PCR.

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

What is the scientific term for a small strongyle infection?

A

Cyathostomiasis

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

Which are more susceptible to anthelmintics: large strongyles or small strongyles?

A

Large strongyles.

Resistance to anthelmintics is an increasing problem in small stronglyes.

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

Name 3 common genera of small strongyles.

A
  • Cyathostomum*
  • Cylicocyclus*
  • Cylicostephanus*
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Which small strongyle life stage is infective? Describe this stage.

A

L3

This stage is free-living on vegetation and retains the sheath from the previous molt.

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

What happens to the L3 cyathostome larva once it is swallowed by the equine host?

A

Sheds its sheath, burrows into the mucosa, molts to L4 larva.

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

What factors can contribute to clinical disease in a horse with a small strongyle infection?

A

Crowding, poor nutrition, poor worming program, etc.

For example, if a horse has bad teeth and is not able to obtain proper nutrition, it is more likely to show signs of disease when infected with small strongyles.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the clinical signs associated with a small strongyle infection in horses?

A

Weight loss or decreased weight of gain

Generalized debility/poor doer

Retention of winter hair coat

May have diarrhea, but not necessarily

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

How would you diagnose a small strongyle infection

A

Age

Clinical signs

Large numbers of strongyle-type eggs in the feces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is larval cyathostomiasis?

A

Clinical syndrome caused by mass emergence of larvae from their mucosal cysts. Causes a massive insult to the gut wall.

Often seen in spring when large numbers of hypobiotic larvae emerge.

Not seen in every small strongyle infection.

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

What is a potential concern of quickly killing adult cyathostomes in an equine gut with anthelmintics?

A

Rapid decline in adult numbers may cause a mass emergence of hypobiotic larvae, resulting in larval cyathostomiasis.

Usually occurs within 2 weeks of treatment.

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

What are the clinical symptoms associated with larval cyathostomiasis?

A

Acute onset of fever

Persistent diarrhea (may contain blood and mucus)

Hypoalbuminemia, neutrophilia, hyperglobulinemia

Severe weight loss

Potentially fatal

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

A horse is showing signs of larval cyathostomiasis. How do you diagnose it?

A

Unfortunately, this is usually done at necropsy.

Because the disease results from LARVAL emergence, you usually cannot detect eggs in the feces.

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

How do you treat larval cyathostomiasis?

A

Anthelmintic:

Moxidectin

Supportive care:

anti-diarrheal drugs

corticosteroids to decrease inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

You detect cyathostomes in your horse herd. DEWORM. DEWORM EVERYTHING.

Right?

A

Chill out, bro.

Strategic deworming should be planned on a farm-by-farm basis.

Take into account which horses are showing signs, sanitation, and husbandry practices.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the main goals of SELECTIVE THERAPY in strongyle control?

A
  1. Control populations in order to avoid clinical signs (i.e. reduce eggs on the pasture).
  2. Control/slow the development of resistance.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What husbandry measures can you implement to help control equine strongyles?

A

Remove vegetation growing in paddocks

Feed dry feed only

Keep horses on a sound nutritional program

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Which two major observations is the concept of selective therapy reliant on?

A

Parasites are unevenly distrubeted (overdispursed)

Stroyngyle egg shedding adult horses is consistent over time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

True or False:

If a horse infected with strongyles is a high egg-shedder, it will remain a high egg-shedder over time.

A

TRUE

Egg shedding over time tends to remain consistent in adult horses.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are refugia in parasite populations?

A

Hosts that have been left untreated in order to maintain parasite genes that remain susceptible to anthelmintics.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What happens if you treat an entire population with anthelmintics? Why are refugia important?

A

Treating an entire population will allow only resistant parasites to survive. Leaving some animals untreated leaves resistance genes in the population.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is cross-resistance?

A

Parasites resistant to one drug in an anthelmintic class are usually resistant to all drugs in that class.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Describe the 80/20 rule

A

20% of horses in a population shed 80% of the parasite eggs.

Remember that parasites are unevenly distributed (overdispersed)

26
Q

What is the suggested theshold for egg content in the feces of horses in order to approve treatment?

A

200 eggs per gram (EPG)

27
Q

What test would you use to detect eggs in the feces?

A

Fecal float

28
Q

What test would you use to quantify the number of eggs in a fecal sample?

A

McMaster chamber

29
Q

What test would you use to determine whether your treatment is reducing the parasite load in a host?

A

Fecal Egg Count Reduction Test (FECRT)

30
Q

What is the formula for FECRT?

A

(EPG pre-treatment) - (EPG 14 days post-treatment) x 100

(EPG pre-treatment)

31
Q

Should you use selective therapy on young horses?

A

Lol nope

Only for use in adult horses

32
Q

What is the egg reappearance period (ERP)?

A

Time interval between last effective anthelmintic treatment and the resumption of egg shedding

33
Q

Cyathostomes show widespread resistance to which class of drugs?

A

Benzimidazoles

34
Q

Parascaris shows widespread resistance to which class of drugs?

A

Macrocyclic lactones

35
Q

Based on their respective resistances, which drugs should you use to treat cyathostomes, and which drugs should you use to treat Parascaris?

A

Cyathostomes - macrocyclic lactones

Parascaris - benzimidazoles

36
Q

Describe the deworming schedule for a newborn horse

A

4 treatments total

Treatments 1 and 2 - benzimidazoles to control ascarids

  • at 3 months, 6 months

(At this point, check FEC to monitor parasite loads)

Treatments 3 and 4 - macrocyclic lactones to control strongyles

  • at 9 months, 12 months
37
Q

What kind of worm is Oesophagostomum sp.?

A

Nematode: True Strongyle

Nodular worm

38
Q

Name the four species of Oesophagostomum and the species they infect.

A
  • O. radiatum*: cattle
  • O. columbianum*: cattle
  • O. venulosum*: small ruminants
  • O. dentatum*: pigs
39
Q

This is an adult Oesophagostomum radiatum. Identify the structures pointed to by the arrows.

A

Cephalic vesicle (right arrow)

Cervical vesicle (left arrow)

*These are out-foldings of the cuticle that wrap all the way around the worm.

40
Q

Where do adult Oesophagostomum live?

A

Large intestine

41
Q

What is the infective stage of Oesophagostomum?

What is the pre-patent period?

A

Sheathed L3

6-7 weeks

42
Q

What are the consequences of re-infection with Oesophagostomum?

A

Localized immune reaction around larvae in mucosa (nodules or mini-abscesses), mostly in large intestine.

43
Q

How long can Oesophagostomum larvae persist inside intestinal mucosal nodules?

A

Less than 3 months.

Worm larvae tend to get trapped in the nodules and die. Nodules will eventually caseate and calcify.

44
Q

What are the clinical signs associated with re-infection with Oesophagostomum?

A
  • Nodules interfere with peristalsis and absorption
  • Anorexia, weight loss, diarrhea, poor wool quality, etc.
  • Thin sow syndrome - chronic flare-ups due to hypobiotic emergence around farrowing
  • Nodules may rupture (rare)
    • If rupture into lumen: ulcerative colitis
    • If rupture out of serosa: peritonitis, adhesions, death
45
Q

True or False:

“Large-mouthed bowel worm” makes a great insult for when you get into bar fights.

A

True, I guess?

46
Q

What is the pre-patent period of Chabertia ovina?

A

6 weeks

47
Q

How many teeth does Chabertia ovina have?

A

None. None teeth.

48
Q

Identify this species found in a goat

A

Chabertia ovini

Note the large, bell-shaped buccal capsule with no teeth.

49
Q

Are there clinical signs associated with low-level Chabertia infections?

A

Meh.

You might see some diarrhea, local hemorrhage into the gut, and somesuch.

50
Q

Identify these adult worms found in the perirenal fat of a pig.

A

Stephanurus dentatus

Note the stout appearance with no lips (do not confuse for an ascarid). Poorly developed copulatory bursa.

Also, the host species and location of the worm was a pretty dead giveaway.

51
Q

What are the modes of infection with Stephanurus?

A

Ingestion of L3

Skin penetration by L3*

Ingestion of earthworm paratenic host carrying L3

*Editor’s note: Aaaah! AAAAHHH!

52
Q

Describe the life cycle of Stephanurus after it has been swallowed

A
  • Migrates from gut to liver. Lives there for usually 2-3 months.
    • Can cause extensive liver damage
  • Exits through liver capsule.
  • Migrates retro-peritoneally to kidney wall and ureters
  • Matures to adult in cysts
  • Lays eggs, which are excreted in the urine
53
Q

What is the pre-patent period of Stephanurus?

How long do the adults live?

A

9-16 months

2 years

54
Q

This is a liver lesion caused by Stephanurus dentatus larvae. Can you think of another worm that causes similar lesions?

A

Ascaris suum

55
Q

What are the clinical signs associated with Stephanurus larval migrations?

A

Skin lesions from penetration sites

Liver fibrosis, cirrhosis, abscesses, adhesions

Poor thrift, emaciation, death

Note: adults in renal tissues may be non-pathogenic

56
Q

You tech hands you a sample. A quick perusal under the scope reveals standard strongyle-type eggs.

Fantastic. There are, like, a bazillion species that fit that description.

Then your tech remembers that the sample came from the urine of a pig. What is your diagnosis?

A

Stephanurus dentatus

57
Q

These worms were found in the perirenal fat of a pig. What species is this?

A

Stephanurus dentatus

Note that when fixed, these worms will appear white, not red.

58
Q

Where do you usually find pigs with Stephanurus infections?

A

In pigs raised outdoors and in wild pigs.

Usually found in the SE US because of larval intolerance to cold.

59
Q

A farmer has this crazy idea that feeding his donkeys pig urine is an important first step in creating a pig-donkey hybrid, or “pigonkey.”

Needless to say, the farmer does not believe in deworming.

A few months after starting this madness, one of the donkeys starts showing signs of posterior paralysis. What do you think happened?

A

Stephanurus dentatus can cause larva migrans in accidental hosts.

On rare occasions, the worm can abberantly migrate to the CNS and cause posterior paralysis.

60
Q

What is the pre-patent period of Stephanurus dentatus?

A

~1 year

(very long pre-patent period)

61
Q

What control measures can you take to rid a pig population of Stephanurus infections?

A
  • Raise pigs on concrete or in confinement
    • Separate pigs from urine, L3 larvae, and earthworms
    • Eggs don’t survive well in cold or dry conditions
  • Use gilt-only breeding program for 3-4 generations
    • Breed at 7-8 months of age (shorter than the worm’s pre-patent period)
    • Sell female after first litter is weaned

serpent taming (13 decks)

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