Lecture 3: Nematodes (part 1) Flashcards Preview

Parasitology 2018 > Lecture 3: Nematodes (part 1) > Flashcards

Flashcards in Lecture 3: Nematodes (part 1) Deck (78):
1

canine ascarid (roundworm)

toxocara canis

eggs, thick shell with dark morula

2

ascarid of cat

toxocara cati

3

ascarid of both dogs and cats

toxascaris leonina (lighter, outer shell is smooth, not dark and rough like other ascarid eggs)

4

what morphological feature can help ID ascarid adults

alae (cuticle) differs by spp

5

ascarids discussed

t. canis
t. cati
toxascaris leonina
baylisascaris procyonis

6

infective stage of T. canis

egg with L2 larvae

7

possible routes of transmission to DH for T. canis

ingestion (direct trans)
transuterine
lactogenic
ingestion of paratenic host

8

direct transmission (fecal) in dogs less than 3 mo old with toxocara canis

"tracheal migration"
ingests L2
larva hatches in SI, penetrates SI and goes to LN, liver, heart, pulmonary arteries, lungs
molts to L3 in alveoli and is coughed up/swallowed
matures in SI to L5

9

direct transmission (fecal) in dogs older than 3 mo old with toxocara canis

"somatic migration"
ingests L2
hatches in SI, penetrates SI and enters cystemic circulation (doesn't penetrate alveoli)
L2 larvae encyst in tissues
NO MATURATION occurs (IS of host stops development)

10

how do puppies get infected with toxocara canis in utero

the hypobiotic L2 larvae mobilize around d42 pregnancy and migrate to fetuses

migrate to liver and molt to L3 and migrate to lungs at birth

11

when can eggs be found in puppy feces infected transuterine by toxocara canis

23-40d old

12

lactogenic transmission of toxocara canis

L2 larvae in mammary tissue passed to pupppies, NO MIGRATION

13

Toxocara canis infection via paratenic host

ingest PH with encysted L2s (rodents). NO MIGRATION

14

routes of infection that do not involve migration in the DH for toxocara canis

lactogenic, paratenic host ingestion

15

toxocara cati direct transmission has __ migration vs the somatic migration seen with toxocara canis

tracheal migration

16

most common route a cat is infected with toxocara cati

ingestion of paratenic host (rodent, cockroach, earthworm)

17

is there migration with direct transmission of toxascaris leonina

no! migration with other spp via direct transmission

18

pathologies caused by ascarides (roundworms)

more problems seen in young with heavy infections

death (rare)
pneumonia
intestinal obstruction V/D
pot belly
Neurologic disorder

19

diagnosing ascrids

fecal float, eggs float nicely and there will be a ton of them. can also see adults in feces

20

treating ascarids

treat mother and litter!
fenbendazole dogs and bitches
selamectin for cats
remove feces daily, rodent and PH control

21

is toxocara canis zoonotic

yes, causes visceral larval migrans
chronic granulomatous lesions in liver, lungs, brain, eye

22

dirt eating childeren may get

toxocara canis, they are a paratenic host

23

ascarid with DH being raccoons, kinkajous, and dogs

baylisascaris procyonis

24

infective stage of baylisascaris procyonis

egg with L3

25

paratenic host for baylisascaris procyonis

mice, rabbits, birds, humans

26

how can humans get baylisascaris procyonis

ingest larvated eggs in contaminated food/water/environment
consuming raw meat

27

CS in paratenic hosts of baylisascaris infections

visceral larval migrans causing neurologic disease
severity of disease depends on number of larvae and spp
rodents, rabbits, birds, primates have high susceptibility

28

CS in paratenic host for baylisascaris infections

low numbers = none
high numbers migrating = respiratory distress, granulomas, invasion of spinal cord, brain, death

29

infective stage of baylisascaris

L2 in egg

30

the esophageal worm

spirocerca lupi

31

DH for spirocerca lupi

caudal esophagus of dogs, cats, and wild canids and felids

32

IH for spirocerca lupi

dung beetle

paratenic hosts: amphibians, repitles, birds

33

spirocerca lupi distribution

worldwide, mainly tropical/subtrop regions

34

adult spirocerca lupi roundworms

bright red and coiled

35

infective stage of spirocerca lupi

L3 in dung beetle

36

migration of spirocerca lupi in DH

L3 migrates from stomach to gastric arteries, aorta (stay here 2+mo) and finally to esophagus where they form nodules/mature/mate

37

CS from spirocerca lupi

roughened aorta
spondylitis of thoracic vertebra
migration to other aberrant sites
esophageal obstruction
granuloma around nodule can develop into sarcoma

38

granulomas formed around spirocerca lupi have been known to become

sarcomas

39

dx spirocerca lupi

fecal float with high spec grav
endoscopy - most sensitive
radiography (caudal esophageal mass, spondylitis)

40

tx spirocerca lupi

ivermectin tried first

41

the physaloptera stomach worm of cats

physaloptera praeputialis

42

the stomach worm of dogs

physaloptera rara

43

IH of physaloptera (stomach worm)

dung beetles, cockroach, grasshoppers

44

paratenic hosts of physaloptera

snake, rat, frog

45

eggs and adult physaloptera

small worms that curl up (males have alae on posterior end)
small, oval, thick shelled smooth egg

46

infective stage of physaloptera

L3 inside IH (beetle, roach, grass hopper)

47

CS physaloptera

usually asymptomatic
can cause edematous stomach with increased mucus and inflammation, melena, chronic vomiting and wt loss

48

dx physaloptera

fecal or vomit float using high spec grav
may see adults in vomitus
endoscopy

49

the cat puke worm or stomach worm of cats

ollulanus tricuspis

50

DH for ollulanus

stomach of cats, foxes, pigs, rarely dogs

51

lifecycle for ollulanus

direct

52

infective stage for ollulanus

female births L3 larvae = infective from birth

53

dx ollulanus tricuspis

worms in vomit
baermann's test
stomach irrication

54

threadworms

strongyloides stercoralis
strongyloides tumefaciens

55

parasitic stage of strongyloides (threadworm)

parthanogenic L3 females! not the free living males/females

migrate lungs - trachea - esophagus - intestine

56

hookworms

ancylostoma
a. caninum
a. braziliense
a. tubaeformae
unicinaria stenocephala

57

Worm in dog that has 3 chitenized teeth on adult worm. Male has a copulatory bursa.

ancylostoma caninum

58

hookworm found in SI of cat, also has 3 pairs of teeth

ancylostoma tubaeformae

59

hookworm found in both dogs and cats but only has 2 pairs of teeth

ancylostoma braziliense

60

hookworm found in dogs in norther america that has a large buccal cavity and cutting plates

unicinaria stenocephala

61

Ancylostoma caninum life cycle

non-larvated eggs passed in feces, embyronate in environment
within 1day L1 hatches
L3 infective stage
infects DH in many ways (oral, skin pen, transplacental, lactogenic, ingestion PH)

62

5 possible ways L3 infects DH

Ingestion L3
skin penetration
transplacental
lactogenic
ingestion PH

63

most common route of infection for ancylostoma caninum

skin penetration!

64

describe the migration in a L3 a. caninum penetrating skin of a puppy

extensive migration
BV, heart, alveoli, bronchi

65

describe the migration in a L3 a. caninum penetrating skin of a older dog (over 3mo)

extensive migration but more of a "somatic route"
the L3 migrate and encyst in the muscle (hypobiotic, dormant)

66

how do you treat the encysted L3 ancylostoma caninum

no treatment for this stage, protected from drugs and host IS

67

how do cats get ancylostoma tubaeformae hookworms

ONLY acquired after birth via INGESTION (environmental contam)

68

most common CS a. caninum infection

anemia; puppies hit hardest due to low iron stores and lack of aquired immunity

69

which hookworm species are most pathogenic, they are voracious bloodsuckers

a. caninum, a. tubaeformae

70

young puppy with deteriorating health, pale mucous membranes, dark liquid feces but a negative fecal

suspect peracute hookworm disease from transmammary infection, enough adults can kill the puppy...treatment often doesn't work and they need blood transfusions

will see CS before see eggs in feces

71

what is acute hookworm disease

sudden exposure of older pups to large numbers of larvae

will have CS before eggs

treatment is effective

72

what is chronic hookworm disease

no CS

eggs in feces and reduced PCV, may be a "poor doer"

73

what is secondary hookworm disease

older dogs that are emaciated and anemic, usually hookworms are NOT the main culprit

74

treatment for a. caninum in dogs

adult worms:
fenbend, moxidectin, pyrantel

L4 larvae: moxidectin "break life cycle"

this treatment is same for other spp hookworm

75

"sand worms" "plumber's itch" "creeping eruption"

L3 skin penatrations in humans (zoonotic) by
ancylostoma braziliense causing cutaneous larval migrans

76

whipworms

trichuris
t. vulpis (dog)
t. campanula (cat)
t. serrata (cat)

77

where are whipworms located in DH

adults Mainly in cecum

78

infective stage for whipworms

embryonated eggs with L2