parasitology 6

Question 1

order spirurida life cycle

Answer 1

indirect- arthropod as intermediate host

Question 2

superfamily filarodiea

Answer 2

filarids
not in the GI tract-usually subcutaneous tissue
females ovoviviparous: produce microfilariae (MF)
MF-pre-L1 stage a stage between egg and L1

Question 3

dirofilaria immitis (heartwrom)-life cycle

Answer 3

definitive host-dogs and wild canids
parasite of pulmonary arteries
ingested by mosquitoes-can hold 12 MF at a time
release L3 (infectious stage) at the bite site
PPP 6-7 months
patency 5 years

Question 4

dirofilaria immitis-pathogenesis

Answer 4

damage roughly proportional to worm number-no clinical signs with low numbers
physical obstruction by vessel
worms cause inflammation in vessel wall-progressive fibrosis in vessel (sclerosis)
reduced cardiac output and compensatory right heart disease
potential thromboembolism

Question 5

dirofilaria immitis-clinical signs

Answer 5

asymptomatic
chronic cough-dyspnea and decreased exercise tolerance
syncope, hemoptysis and congestive heart failure
death

Question 6

dirofilaria immitis-diagnosis

Answer 6

annual test recommended
antigen test and microfilaria check

Question 7

dirofilaria immitis-treatment

Answer 7

preventive is better than treatment

Question 8

dirofilaria immitis-abnormal host

Answer 8

cats-less successful in cats
more likely to migrate to abnormal sites than in dogs
most infected cats show no signs

Question 9

habronema and draschia spp

Answer 9

lives in nodules in equine stomach
stable and house fly
L3 can deposited by mistake in other locations-mucocutaneous junction-wounds and larva invade areas and survive but don’t develop
horse ingests fly and L3 goes to stomach
if fly lands on eye and L3 are deposited, it does not complete life cycle but causes granuloma

Question 10

trichuris vulpis-whipworms

Answer 10

dogs, whipshaped, direct life cycle and bipolar eggs passed in feces
embryonated eggs is in the infective stage
PPP: 3 months-impact diagnosis and treatment
many infections asymptomatic
clinical disease: diarrhea and blood: anemia if severe
pigs and ruminants

Question 11

oxyurida-pin worms

Answer 11

small adults in large intestine
species in horses, rodents, ruminants, reptiles and people
not very pathogenic
direct life cycle
eggs have polar plug

Question 12

oxyuris equi

Answer 12

common equine pinworm
infection from igestion of egg
fertilized females migrate from L1 to rectum and onto skin-glue eggs to hairs in the perianal area
causes pruritis, irritation from worm movememnt and egg glue