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Parasitology > Lice > Flashcards

Flashcards in Lice Deck (83)
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1
Q

Kingdom: Phylum: Class: Order

A

Animalia Arthropoda Insecta Phthiraptera

2
Q

Wings

A

None

3
Q

Divisions

A

Head, thorax, abdomen

4
Q

Body shape

A

Dorso-ventrally flattened

5
Q

Number of segments in antennae

A

3-5 segments

6
Q

Type of parasite

A

Obligate, permanent parasite

7
Q

Specificity

A

Host and site specific

8
Q

What is the claw size of a louse related to?

A

Fibre diameter

9
Q

Can lice survive off a host?

A

No, whole lifecycle is found on a host

10
Q

Pairs of legs

A

3

11
Q

Life cycle

A

Egg stuck to hair

No metamorphosis

3 nymphal stages

12
Q

Length of life cycle

A

2-3 weeks

13
Q

Two taxonomic groups lice are divided into

A

Anoplura

Mallophaga

14
Q
A

A = Anoplura

B = Mallophaga

15
Q

Anoplura: feeding strategy

A

Sucking lice Feed on blood or tissue fluids

16
Q

Anoplura: # of segments on antennae

A

5

17
Q

Anoplura: shape of head

A

Longer than broad and pointed

18
Q

Anoplura: hosts

A

Mammals only

19
Q

Anoplura: three families

A

Haematopinidae Linognathidae Pediculidae

20
Q

Genera of Haematopinidae family

A

Haematopinus

21
Q

Genera of Linognathidae family

A

Linognathus Solenopotes

22
Q

Genera of Pediculidae family

A

Pediculus Phthirus

23
Q

Anoplura: habitat

A

Coarse hairs (mane, tail) Eggs readily visible

24
Q

Anoplura: colour/size

A

Large, black or blue

25
Q

Anoplura: transmission

A

Contact

26
Q

Anoplura: treatment

A

Topical or oral insecticide

27
Q

Mallophaga: feeding strategy

A

Biting lice Feed on epidermis, feathers

28
Q

Mallophaga: shape of head

A

Head broad, rounded

29
Q

Mallophaga: antennae

A

Thin, 4-5 segments

30
Q

Mallophaga: hosts

A

Mammals and birds

31
Q

Mallophaga: habitat

A

Fine body hairs Eggs concealed

32
Q

Mallophaga: colour/size

A

Small, yellow

33
Q

Mallophaga: transmission

A

Contact

34
Q

Mallophaga: treatment

A

Topical only

35
Q

Mallophaga: Genera with Mammal hosts

A

Damalinia Heterodoxus Trichodectes Felicola

36
Q

Mallophaga: Genera with Bird hosts

A

Menacanthus Lipeurus Gonioides Goinocotes

37
Q

Lice of the sheep

A

Body louse: Damalinia ovis Face louse: Linognathus ovillus Foot louse: Linognathus pedalis

38
Q
A

A = Damalinia ovis

B = Linognathus ovillus

C = Linognathus pedalis

39
Q

Damalinia ovis: features

A

Small yellow louse 30% properties affected Medium rainfall areas

40
Q

Damalinia ovis: effect on host

A

Feeds on stratum corneum Hypersensitivity Irritation, rubbing “Pulled wool” Reduced wool production

41
Q

Damalinia ovis: diagnosis

A

Find lice on sheep Part wool and look Minimum detection level 1000 lice per sheep Lice colonial and photophobic

42
Q

How long do D. ovis eggs take to hatch?

A

10 days

43
Q

How long is the lifecycle of D. ovis?

A

35 days

44
Q

How long can D. ovis live off the host?

A

1 week

45
Q

What is D. ovis affected by?

A

Temperature Moisture Sunlight

46
Q

Effect of temperature on D. ovis

A

Optimum temperature 37 deg At low temperatures, eggs do not develop At high temperatures (above 39) few eggs are laid Lower numbers in summer

47
Q

Effect of moisture on D. ovis

A

If humidity > 90%, eggs do not hatch Heavy rain can kill eggs

48
Q

Effect of sunlight on D. ovis

A

Exposure to sunlight kills lice Shearing removes 30-50% of lice as lice are exposed to UV radiation

49
Q

When should D. ovis be treated chemically?

A

After shearing

50
Q

What treatments are available?

A

Dips: Organophosphates or synthetic pyrethroids Pour-ons: Synthetic pyrethroids

51
Q

Linognathus pedalis

A

Large blue louse Feeds on blood Found on feet, scrotum and belly Can develop at lower temperatures than D. ovis Attaches eggs to coarser hairs than D. ovis

52
Q

What’s special about L. pedalis?

A

Can survive on pasture for 18 days Can be transmitted through pasture

53
Q

Linognathus ovillus

A

Uncommon Found on face

54
Q

Lice of the goat

A

Damalinia caprae Linognathus africanus & stenopsis

55
Q

Lice of the horse

A

Body louse: Damalinia equi Sucking louse: Haematopinus asini

56
Q
A

A = Damalinia equi

B = Haematopinus asini

57
Q

How is Damalinia equi transmitted?

A

Contact

58
Q

How is Haematopinus asini transmitted?

A

Riding and grooming equipment

59
Q

Damalinia equi

A

Small yellow louse Found on sides of neck and flanks

60
Q

Haematopinus asini

A

Large dark louse Occurs on coarser diameter hairs Species can survive away from host for several days

61
Q
A

A = Damalinia bovis

B = Haematopinus eurysternus

C = Solenopotes capillatus

D = Linognathus vituli

62
Q

Lice of cattle

A

Body louse: Damalinia bovis Sucking lice: Short nosed cattle louse: Haematopinus eurysternus Tubercle bearing louse: Solenopotes capillatus Long nosed cattle louse: Linognathus vituli

63
Q

Cattle sucking lice

A

Maximum numbers in winter Found on head, neck, back, tail Causes rubbing Larger numbers in sick animals

64
Q

Lice of the pig

A

Sucking louse: Haematopinus suis

65
Q
A

Haematopinus suis

66
Q
A

Haematopinus suis

67
Q

Haematopinus suis: Lifecycle

A

Eggs hatch 12-14 days Lice mature 12 days

68
Q

Haematopinus suis: size

A

Very large, mistaken for a tick

69
Q

Haematopinus suis: pathogenesis

A

May spread pig pox and swine fever Causes red welts on skin –> production loss

70
Q

Lice of the dog

A

Trichodectes canis Heterodoxus spiniger Linognathus setosus

71
Q
A

A = Trichodectes canis

B = Linognathus setosus

C = Heterodoxus spiniger

72
Q

Pathogenesis of Trichodectes canis

A

Can act as an intermediate host for the “flea tapeworm” D. caninum

73
Q

Lice of the cat

A

Felicola subrostratus

74
Q
A

Felicola subrostratus

75
Q

Felicola subrostratus

A

Biting louse Pointed head Seen on aged or sick cats

76
Q

Significance of heavy lice infestation in cats

A

May indicate underlying disease as cats are generally good groomers in health

77
Q

Lice of poultry

A

Many genera, all biting Menacanthus Stramineus most common

78
Q
A

A = Menacanthus Stramineus

B = Lipeuris caponis

79
Q

Pathogenesis of poultry lice

A

Irritation Feather loss Poor growth Reduced egg production

80
Q

Treatment of poultry lice

A

Dust baths, aerosols, vaporisers

81
Q

Lice of humans

A

Head/body louse: Pediculus humanus, Pediculus capitis

Pubic louse: Phthirus publis

82
Q

Pathogenesis of lice of humans

A

Vectors of typhus

83
Q
A