small animal parasites

Question 1

what is a cestode

Answer 1

• tapeworms
• chain of proglottids attached by a head (scolex)
• distal segments full of eggs shed in feces (fecal exam for eggs unreliable)
• distal segment disintegrates and eggs are released
• indirect lifecycle
• immature form is metacestode

Question 2

list common tapeworm species

Answer 2

Question 3

highlight some features of taenia spp anatomy

Answer 3

• suckers and hooks (2 rows) (what causes damage in infection)
• proglottids (segments) with one genital pore
• striated shell (hooks visible within)
• cysticerus

Question 4

which species of taenia are zoonotic

Answer 4

• taenia solium
• taenia saginata

both from eating undercooked meat

Question 5

what is the intermediate and definitive host of taenia taenieaformis

Answer 5

intermediate: rodent
definitive: cat

only feline spp of taenia

Question 6

list taenia spp of dogs and their respecitve intermediate hosts

Answer 6

Question 7

list clinical signs of taeniasis in animals

Answer 7

• perineal irritation, licking and chewing
• scooting
• owner finds segments (look like grains of rice)

Question 8

what is Dipylidium caninum, the IH and DH

Answer 8

tapeworm
- intermediate host = flea/louse
- definitive host = SI of dog and cat

Question 9

what is unique about the proglottids of dipylidium caninum

Answer 9

2 genital pores

Question 10

outline the lifecycle of Dipylidium caninum

Answer 10

Question 11

outline the lifecycle of echinococcus granulosus

Answer 11

Question 12

is echinococcus granulosus zoonotic

Answer 12

yes - significantly so, especially in children
- forms cycts in the liver and lung

Question 13

outline the lifecycle of echinococcus multilocularis

Answer 13

Question 14

list nematodes of small animals and which species they infect

Answer 14

Question 15

outline the lifecycle of toxocara canis

Answer 15

Question 16

how is toxocara cati similar/different to toxocara canis

Answer 16

• lifecycle generally the same
• EXCEPT in utero infection does NOT occur
• kittens can be infected trans-mammary

Question 17

what is toxascaris leonina

Answer 17

• affects dogs and cats
• L2 in egg/paratenic host ingested
• PPP 11 weeks
• develops in GIT only - non-migratory
• signs rare
• zoonotic
• eggs released into environment

Question 18

what are the differences between toxocara canis and toxascaris leonina eggs

Answer 18

T. canis: pitted shell, more round
toxascaris leonina: smooth shell, more transparent, more oval

Question 19

what are the 3 important species of hook worms

Answer 19

• ancylostoma caninum (dogs)
• ancylostoma tubaeformae (cats)
• uncinaria stenocephala (dogs)

Question 20

outline the lifecycle of ancylostomes

Answer 20

Question 21

outline the difference in lifecycle of uncinaria stenocephala compared to ancylostoma spp

Answer 21

• infects dogs
• eggs in feces, L3 in environment
• L3 ingested and establishes infection in SI
• PPP = 2 weeks
• NO pulmonary migration
• larvae penetrate skin
• signs rare (diarrhea and dermatitis)

Question 22

what is trichuris vulpis

Answer 22

canine whip worm

Question 23

how is trichuris vulpis diagnosed

Answer 23

• demonstration of barrel shaped eggs with conspicuous plugs at both ends in the feces

Question 24

how is trichuris vulpis treated

Answer 24

use of anthelmintics such as fenbendazole and oxfendazole

Question 25

in what part of the intestines can you fine adult whipworms

Answer 25

large intestine

Question 26

why would fresh blood in the feces cause a veterinarian to suspect whipworm infection

Answer 26

- similar to hookworms - causes digested blood and black "tarry" appearance in feces

Question 27

why should dogs with whipworms be treated monthly for 3 months as apposed to 2 weeks later as with hookworms

Answer 27

becuase the 3 months prepatent period duriing which immature whipworms are not susceptible to anthelmintics, treatment administration spans 3 months