Nematodes Small Animal

Question 1

What is a nematode?

Answer 1

Round worm (hookworm, whipworm, heartworm, lungworm)

Question 2

What is the general morphology of nematodes?

Answer 2

Unsegmented, round in cross section

Question 3

Which nematodes effect the GI system?

Answer 3

Toxocara canis/cati
Ancylostoma spp
Trichuris spp

Question 4

Which nematodes effect the circulatory system?

Answer 4

Dirofilaria immitus

Question 5

Which nematodes effect the respiratory system?

Answer 5

Eucoleus spp

Question 6

Which nematodes effect the urogenital system?

Answer 6

Dioctophyma spp

Question 7

Which nematodes effect the optic system?

Answer 7

Thelazia spp

Question 8

Which nematodes effect the integumentary system?

Answer 8

Rhabditis spp

Question 9

Where can Toxocara spp be found in the body?

Answer 9

Primarily small intestine. Also stomach

Question 10

How to diagnose Toxocara spp

Answer 10

Fecal floatation or direct fecal smear

Question 11

What is the general life cycle for Toxocara spp?

Answer 11

Egg is passed by the initial host and ingested by the next host. Egg hatches in the new host and larva enters the blood. Larva migrates (coughed up and reswallowed) to the lungs. Matures in small intestine

Question 12

What is the prepatent period for Toxocara canis?

Answer 12

3-5 weeks

Question 13

What is the prepatent period for Toxocara cati

Answer 13

~8 weeks

Question 14

Who is the paratenic host for Toxocara cati

Answer 14

Mouse. Mouse is infected then cat eats the mouse

Question 15

What type of worm is Ancylostoma spp?

Answer 15

Hookworm

Question 16

Where does Ancylostoma spp attach?

Answer 16

Mucosa of the small intestine. Cuts into tissues and feeds on blood

Question 17

T/F Ancylostoma spp can be via penetration or ingestion

Answer 17

True

Question 18

Zoonosis potential of Ancylostoma spp

Answer 18

Migrates into dermis & creates red migration tracts. Severe pruritis. Human in abberant host and life cycle cannot be completed

Question 19

Life cycle of Ancylostoma spp

Answer 19

Eggs are passed from initial host 2-4 weeks after infection. Egg Matures into infective larva in the ground, and are reingested or can penetrate through unprotected skin. Immature worms migrate to small intestine & mature

Question 20

What are the different species in Ancylostoma spp?

Answer 20

Ancylostoma caninum (canine)
Ancylostoma tubaeforme (feline)
Ancylostoma brazilienze (canine/feline)
Ancylostoma stenocephala (canine)

Question 21

Diagnosis of Trichuris vulpi

Answer 21

Fecal float. Longer float times because ova doesn’t float well

Question 22

What is the lifecycle of Trichuris vulpi

Answer 22

Egg passed by the initial host q3 days. Larvates in environment. Egg is ingested by new host and hatches, Matures in small and large intestine. Attaches to cecum/colon and head threads through mucosa and perforates small vessels

Question 23

General anatomy of Trichuris vulpi

Answer 23

Thin, anterior section is head
Thick, posterior section is reproductive
Feeds on blood

Question 24

Who are the hosts for Dirofilaria immitus

Answer 24

Definitive: canine
Intermediate: mosquitos
Incedental: human
Cats & ferrets can be infected, but not an infection source

Question 25

Where does Dirofilaria immitus reproduce in canines?

Answer 25

Right ventricle & pulmonary arteries

Question 26

Dirofilaria immitus lifecycle

Answer 26

Adults reproduce creating microfilaria. Mosquito picks up microfilaria through blood meal, and deposits on new host vis puncture site where mosquito feeds. Larva develops during migration to the heart

Question 27

What is Dirofilaria immitus prepatent period

Answer 27

6 months

Question 28

Dirofilaria immitus diagnosis

Answer 28

ELISA antigen/antibody test Modified knott's test Buffy coat layer evaluation

Question 29

Eucoleus spp

Answer 29

lungworm

Question 30

Eucoleus spp prepatent period

Answer 30

40 days

Question 31

Eucoleus spp lifecycle

Answer 31

Passed in feces, larva becomes infectious while still w/I egg Egg ingested & hatches in small bowel where it penetrates and enters blood vessels. Migrates to lungs where it penetrates alveoli and migrates to larger airways. Coughed up & reswallowed

Question 32

Eucoleus spp diagnosis

Answer 32

Fecal float or sputum smear

Question 33

Eucoleus spp zoonosis

Answer 33

Ingestion of ova

Question 34

Dioctophyma renale

Answer 34

Urogenital nematode

Question 35

T/F Dioctophyma renale is the largest parasitic nematode?

Answer 35

True

Question 36

Dioctophyma renale prepatent period

Answer 36

18 weeks

Question 37

Dioctophyma renale diagnosis

Answer 37

Urine sediment

Question 38

Dioctophyma renale lifecycle

Answer 38

Unembryonated eggs are passed via urine & embryonate in water. Eggs are ingested by intermediate host (earthworms). Worm +/- being eaten by paratenic host. Definitive host eats worm or paratenic host

Question 39

Dioctophyma renale hosts

Answer 39

Definitive: canine Intermediate: earthworms Paratenic: fish/frogs

Question 40

Dioctophyma renale zoonosis

Answer 40

Human is incidental host. Ingest paratenic host via undercooked fish

Question 41

What is a nematode?

Answer 41

Roundworm

Question 42

What is the general morphology of nematodes?

Answer 42

Unsegmented, round in cross section

Question 43

Which nematodes effect GI?

Answer 43

Toxocara canis/catis Ancylostoma spp Trichuris spp

Question 44

D:

Answer 44

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Question 45

Which species is known as a whipworm?

Answer 45

Trichuris vulpi