NEMATODES: Oxyuriodea spp.

Question 1

What is the common name for Oxyuris equi?

Answer 1

Large pinworm

Question 2

What type of life cycle does Oxyuris equi have?

Answer 2

Direct

Question 3

Who are the hosts for Oxyuris equi?

Answer 3

All equids

Question 4

What distinguishing characteristic can be used to differentiate Oxyuris equi infections from Trichuris spp. or Capillaria (Eucoleus) spp. infections in equids?

Answer 4

Oxyuris equi has only a single operculum, while Trichuris and Capillaria (Eucoleus) spp. have two polar plugs

Question 5

What gender of adults will be seen in Oxyuris equi infections in equids? Why?

Answer 5

Females, as they emerge out the anus to lay their eggs

Question 6

What is predliction site for Oxyuris equi?

Answer 6

Dorsal colon

Question 7

What is laid with the eggs of Oxyuris equi?

Answer 7

A gelatinous substance that is an irritant

Question 8

What pathogenesis is associated with Oxyuris equi infections?

Answer 8

• Pruritis
• Peri-anal irritation
• Broken hair/ areas of no hair

Question 9

What diagnostic method is needed for Oxyuris equi infections?

Answer 9

Tape method, or perianal scrapings

Question 10

Why is reinfection quite common with Oxyuris equi infections?

Answer 10

They will display behaviors associated with rubbing irritated areas against foreign objects, etc. which can further contaminate areas

Question 11

What pinworm is associated with people, especially young children as a result of poor hygiene, etc.?

Answer 11

Enterobius vermicularis

Question 12

When is Enterobius vermicularis active?

Answer 12

At night

Question 13

A member of Filaroidea, Dirofilaria immits will have what type of life cycle?

Answer 13

Indirect

Question 14

Who are the final hosts of Dirofilaria immitis?

Answer 14

Dogs, cats, and other mammals

Question 15

True or False: Members of the super family Filaroidea will inhabit the small intestine, and other areas along the alimentary canal.

Answer 15

False, they are unique in that they do not inhabit the alimentary canal

Question 16

Is Dirofilaria immitis zoonotic?

Answer 16

Yes

Question 17

Who is the IH for Dirofilaria immitis?

Answer 17

Mosquitoes

Question 18

What can be seen in a blood smear for dogs infected with D. immitis?

Answer 18

Microfilaria (L₁’s)

Question 19

What technique is often used for microfilaria infections?

Answer 19

Modified Knot’s Technique

Question 20

True or False: Microfilariae are at an earlier developmental stage than first-stage larvae, and do not contain a digestive tract.

Answer 20

True

Question 21

True or False: The mosquito, which serves as an intermediate host for D. immitis, can support multiple stages of D. immitis (L₁ to L₃) at one time.

Answer 21

True

Question 22

How long can it take for D. immitis L₃’s to molt into L₄’s?

Answer 22

2 - 3 days

Question 23

How long does it take for L₄’s to molt into Immature adults of D. immitis?

Answer 23

2 - 3 months

Question 24

Where do Dirofilaria immitis L₄’s migrate to once in the host?

Answer 24

They travel within the SQ tissues of the thorax and abdomen

Question 25

Where do *D. immitis* L₄'s mature into adults?

Answer 25

In the heart, as they get lodged into the distal part of the pulmonary aa.

Question 26

As a result of increased burdens of *D. immitis*, where can they also be located, aside from the pulmonary aa.?

Answer 26

Right ventricle and atria, and vena cava

Question 27

What pathogenesis is assocaited with heartworms?

Answer 27

* Endothelium is destroyed * Fluid leakage * Thrombus * Tortuous arteries * Increased resistance * Post-caval syndrome

Question 28

What bacterium is associated with *D. immitis?*

Answer 28

*Wolbacchia spp.*

Question 29

As *Wolbacchia spp.* are needed for the overal function of *D. immitis*, what antibiotic can be administed to treat against *Wolbacchia spp.?*

Answer 29

Doxycycline

Question 30

True or False: Severity of clinical disease is not determined by pulmonary blood flow.

Answer 30

False, it is

Question 31

What common signalment is associated with *Dirofilaria immitis?*

Answer 31

Large breeds, Males, Over 6 months of age

Question 32

While ________ tests can be used to confirm infection of *D. immitis,* though it requires at least 3 sexually mature females present in the host, a ______ \_\_\_\_\_\_ can be use as well to identify any mirofilariae.

Answer 32

**Antigen** **Blood smear**

Question 33

What are occult infections?

Answer 33

Adult parasites are present, but there are no seen eggs or young larvae present

Question 34

True or False: Adult dogs should be tested for *D. immitis* prior to beginning prevention.

Answer 34

True

Question 35

Monthly preventatives are directed and used for the elimination of what stages of *Dirofilaria immitis*?

Answer 35

L₃ and early L₄'s

Question 36

While feline infections are uncommon, why are they more fatal?

Answer 36

* High risk of complications * Stronger immune response to infections * Infections occur in the lungs, rather than in the aa. * No approved treatment

Question 37

What type of life cycle is associated with *Acanthocheilonema reconditum*?

Answer 37

Indirect life cycle

Question 38

What IH's are associated with the life cycle of *Acanthochelionema reconditum*?

Answer 38

Fleas, ticks, and lice

Question 39

Where are adult *Acanthocheilonema reconditum* found? Where are the microfilariae?

Answer 39

**Adult:** Subcutis **Microfilariae:** Blood

Question 40

The end of *A. reconditum* or *D. immitis* is blunter than the other?

Answer 40

*A. reconditum* has a blunter anterior end than that of *D. immitis*

Question 41

*Setaria equina* has what type of life cycle? Is there an IH?

Answer 41

Indirect life cycle **IH:** mosquito

Question 42

Where will adult *Setaria equini* be found in equids? Microfilariae?

Answer 42

**Adult:** Peritoneal cavity **Mff:** Blood

Question 43

*Onchocerca cervicalis* is associated with what disease in people?

Answer 43

River blindness

Question 44

What IH is required for *Onchocerca cervicalis?*

Answer 44

*Cuilcoides spp*. aka Biting midges

Question 45

What is the predilection site for *Onchocerca cervicalis*?

Answer 45

**Adults:** CT **Microfilariae:** Tissue spaces of skins

Question 46

What diagnostic test is associated with *Onchocerca cervicalis*?

Answer 46

As a result of skin infections, a skin biopsy can be used for diagnosis