Helminths (Rhabditida)

Question 1

What is the only superfamily in the Rhabditoidea order?

Answer 1

Rhabditoidea

The families discussed include Rhabditidae, Panagrolamidae, and Strongyloididae.

Question 2

Which genera are included in the families of Rhabditoidea?

Answer 2

• Rhabditis (genus Rhabditis)
• Halicephalobus (genus Halicephalobus)
• Strongyloides (genus Strongyloides)

Question 3

In cladistic taxonomy, where is Rhabditis located?

Answer 3

Clade V

Question 4

Where do Halicephalobus and Strongyloides appear in cladistic taxonomy?

Answer 4

Clade IV

Question 5

What condition can Rhabditis (Pelodera) strongyloides cause?

Answer 5

Pruritic, hyperemic dermatitis

Question 6

What is commonly associated with dermatitis caused by Rhabditis in dogs?

Answer 6

Damp straw bedding

Question 7

What is the method of diagnosis for Rhabditis strongyloides infection?

Answer 7

Finding nematode larvae with a rhabditiform esophagus in skin scrapings or histologic sections

Question 8

What is the length range of adult Rhabditis strongyloides?

Answer 8

1 to 2 mm

Question 9

What treatment was successful for Rhabditis strongyloides in hounds?

Answer 9

Ivermectin

Question 10

What nematode causes parasitic otitis externa in cattle?

Answer 10

Rhabditis bovis

Question 11

What percentage of Gyr cattle had detectable nematodes in the studies mentioned?

Answer 11

63% and 89%

Question 12

What is the size range of Halicephalobus gingivalis?

Answer 12

250 to 450 by 15 to 20 µm

Question 13

What is unique about the male Halicephalobus gingivalis?

Answer 13

A male of this species has yet to be reported

Question 14

What kind of infections has Halicephalobus gingivalis been reported in?

Answer 14

Fatal human infections

Question 15

What is the primary life stage of Strongyloides that is important for diagnostics?

Answer 15

Filariform third-stage larva

Question 16

What is unique about the female Strongyloides?

Answer 16

It is parthenogenetic and does not have parasitic males

Question 17

What are the two cycles of Strongyloides life history?

Answer 17

• Homogonic cycle
• Heterogonic cycle

Question 18

What is the major mode of transmission for Strongyloides spp.?

Answer 18

Transmammary transmission

Question 19

Which species of Strongyloides is known to affect humans and dogs?

Answer 19

Strongyloides stercoralis

Question 20

What clinical signs may accompany severe S. stercoralis infection in dogs?

Answer 20

Bronchopneumonia and severe watery or mucous diarrhea

Question 21

What phenomenon can lead to chronicity in S. stercoralis infections in humans?

Answer 21

Internal autoinfection

Question 22

What is the primary symptom of S. westeri in foals?

Answer 22

Diarrhea

Question 23

At what age do foals begin to shed S. westeri eggs?

Answer 23

10 days to 2 weeks after birth

Question 24

What can cause hyperinfection in S. stercoralis in immunocompromised individuals?

Answer 24

Reinvasion by infective larvae

Question 25

True or False: Strongyloides is only found in domestic animals.

Answer 25

False

Question 26

What is the typical age range when diarrhea frequently afflicts foals?

Answer 26

Between the ninth and 13th days of life

Question 27

What parasite correlates with foal-heat diarrhea?

Answer 27

S. westeri

Question 28

How long can heavy infections of S. westeri persist in foals?

Answer 28

10 weeks

Question 29

What is the prevalence of S. westeri in Kentucky thoroughbred foals as of recent surveys?

Answer 29

1.5%

Question 30

What treatment is commonly used for S. westeri in foals?

Answer 30

Ivermectin

Question 31

What are the clinical signs of S. papillosus infection in goats?

Answer 31

Dehydration, inappetence, emaciation, weakness, cachexia, diarrhea, anemia, respiratory distress, abnormal stools

Question 32

What is the most susceptible age group for S. papillosus infection in goats?

Answer 32

Kids 6 weeks to 6 months of age

Question 33

What can happen to goats infected with S. papillosus?

Answer 33

Death typically occurred within 9 to 30 days after exposure

Question 34

What was the effect of inoculating live parthenogenetic females of S. papillosus in lambs?

Answer 34

Continuous sinus tachycardia and death due to cardiac arrest

Question 35

What drastic outcomes were observed in calves raised in confinement on sawdust infected with S. papillosus?

Answer 35

Dying in agony due to infections

Question 36

What is S. ransomi and where does the female lie?

Answer 36

A parasite that lies deeply embedded in the mucous membrane of the small intestine

Question 37

How do S. ransomi larvae develop into infective third-stage filariform larvae?

Answer 37

In 2 or 3 days after being shed in feces

Question 38

What is the key to the epidemiology of S. ransomi infection?

Answer 38

Transmammary infection

Question 39

What is the result of piglets being separated at birth from their dam regarding S. ransomi?

Answer 39

They were free of S. ransomi infection

Question 40

What are the symptoms of strongyloidosis of piglets?

Answer 40

Acute enteritis with bloody diarrhea, rapid emaciation, anorexia, anemia, stunting

Question 41

What is the treatment of choice for Strongyloides infections across various species?

Answer 41

Ivermectin

Question 42

What alternative treatments are available for S. ransomi and S. papillosus?

Answer 42

Levamisole and doramectin

Question 43

Fill in the blank: The use of _______ has markedly reduced the presence of S. westeri on many farms.

Answer 43

Ivermectin

Question 44

True or False: Ivermectin treatment is effective in removing larvae from tissues in dogs with S. stercoralis.

Answer 44

False