ASCARIDS

Question 1

ascarids are nematodes - name some differences they have

Answer 1

no buccal cavity

3 x lips (alae)

no bursatransport and paratenic hosts

cause no mucosal damage

Question 2

what is a paratenic host?

Answer 2

not essential but some development can happen here

Question 3

describe the basic ascarid lifecycle

Answer 3

• adults in SI
• iL2 develpes in egg
• egg ingested
• iL2 hatches and penetrates SI wall
• hepato-tracheal migration
• L3 coughed and swallowed
• L5 in SI

Question 4

name the 2 equid ascarid worms

Answer 4

1. parascaris equorum
2. oxyuris equi

Question 5

what is the PPP for both equid ascarsd (p. equorum and O. equi)

Answer 5

p equorum = 12wks

o. equi = 5mths

Question 6

what is another name for o. equi?

Answer 6

pinworm

• pointed tails (v thin!)

Question 7

what is the pathogenesis of p.equorum?

Answer 7

foals-foal

unthrifty, cough, kg loss

NO DIARRHOEA

Question 8

what are the characteristics of the lifecycle of pinworm?

Answer 8

eggs laid perianal skin

iL3 develops in the egg after shed

larval stages develop in the crypts

adults in the LI!

causes pruritis

Question 9

what is the PPP of toxocara canis ?

Answer 9

4-6wks

Question 10

what differs in the transmission of t. canis, t. cati and toxascaris leonina?

Answer 10

t. canis = T-Placental @ d40; TMammary when drink milk and ingestion of paratenic host results in patent infection

T. cati = paratenic and TP dont migrate so no patent infection. There is no T mammary.

T. leonina = only infections if ingests eggs, paratenic host. there is no migration ever.

Question 11

how do you distinguish the eggs of t. cati, t. canis and t. leonina?

Answer 11

t. leonina has ovoid shaped eggs, other two are round and thick

Question 12

what is the pathogenesis of t. canis/cati?

Answer 12

asympt

no d+

puppies –> pot bellied, unthrifty

Question 13

how can t. canis and t. cati and t. leonina be controlled?

Answer 13

treat adults with MLs and BZs

T-pacental transmission = fenbendazole @ d42

• targets when re-activated and migrating

worming protocol @ 2, 4, 6 wo; 3, 6, mo; 3-6mths after

Question 14

what are the zoonotic risks from keeping dogs and cats as pets and which spp is most highly zoonotic?

Answer 14

NO risk from t. leonina

DZ =

visceral larval migrans from them hatching and migrating (L2)

ocular toxocariasis is migrates to eyes –> blind