Lice

Question 1

Describe the general features of lice

Answer 1

• Phthiraptera
• Hemimetabola
• Love close to skin
• Lay eggs
• Highly specialised
• Limited/single host species range
• Split into chewing vs sucking lice

Question 2

Describe the basic morphology of lice

Answer 2

• Claws
• Dorso-ventrally flattened
• Wingless
• Mouthparts adapted to chewing or sucking

Question 3

Describe the appearance of louse eggs

Answer 3

• Pale, translucent
• Suboval
• Firmly glued to hairs near skin
• Chicken lice lay eggs in large maasses at base of feathers

Question 4

How are lice transmitted?

Answer 4

Direct contact

Question 5

Describe the 3 types of lice found on humans

Answer 5

• Head, body, pubic
• Head and body are different morphotimes of the same species
• Head: Pediculus humanus capitus
• Body: Pediculus humans corporis
• Pubic: Phthirus pubis

Question 6

What are the suborders of lice?

Answer 6

• Anoplura (sucking lice)
• Rhynchophthirina (elephant and warthog lice)
• Amblycera and Ischnocera (chewing lice)

Question 7

Name the genuses of sucking lice

Answer 7

• Haematopinus

- Linognathus

Question 8

What are the host species for Haematopinus?

Answer 8

• Pigs
• Cattle
• Horses

Question 9

What are the host species for Linognathus?

Answer 9

• Cattle
• Sheep
• Goats
• Dogs

Question 10

Name the genuses of chewing lice

Answer 10

• Damalina (Bovicola)
• Felicola
• Trichodectes
• Lipeurus
• Cuclogaster
• Menacanthus
• Glyricola
• Gyropus

Question 11

What genus of chewing lice are found in cattle, sheep, goats and horses?

Answer 11

Damalina (Bovicola)

Question 12

What genus of chewing lice are found in cats?

Answer 12

Felicola

Question 13

What genus of chewing lice are found in dogs?

Answer 13

Trichodectes

Question 14

What genuses of chewing lice are found in domestic birds?

Answer 14

• Lipeurus
• Cuclotogaster
• Menacanthus

Question 15

What genuses of chewing lice are found in guinea pigs?

Answer 15

• Gliricola

- Gyropus

Question 16

Describe the common appearance of sucking lice

Answer 16

• Often found with mouthparts embedded in skin
• Relatively large
• Often at 45degrees to skin (feeding)

Question 17

Describe the common appearance of chewing lice

Answer 17

• Fairly active
• Not embedded
• Can be seen moving through hair of host

Question 18

What is pediculosis?

Answer 18

Infestation of lice

Question 19

What are the direct effects of pediculosis?

Answer 19

• Pruritus
• Dermal irritation
• Unthrifty appearance
• Rough coat
• Lowered production in farm animal
• Loss of hair and local scarification
• Severe infestations of sucking lice may lead to anaemia

Question 20

What are the indirect effects of pediculosis?

Answer 20

• Can act as vectors
• Rickettsia prowazekii (typhus)
• Borrelia recurrentis (louse-borne relapsing fever)
• Bartonella quintana (trench fever)
• Swine pox
• trichodected can be intermediate hosts for Dipylidium caninum

Question 21

Outline lice and large animals

Answer 21

• Infested animals bite, scratch and rub selves
• Causes self-truama
• May damage fences, trees and buildings
• Welfare and economic considerations
• Damage to hide downgrades value of leather
• Weight loss, poor milk production
• Anaemia likely if large numbers of lice involved
• Usually seen on stressed, underfed or unwell animals

Question 22

Outline lice in small animals

Answer 22

• Not common pest of companion animals
• Mainly rescues, puppy or kitten farms
• More common in elderly
• Poor health, long coat predispose
• Some species more irritating that others

Question 23

Outline lice in birds

Answer 23

• Not highly pathogenic to adult birds
• May be fatal to chicks
• Damaged skin = secondary bacterial infections
• Restlessness, feather plucking, feather damage, cessation of feeding, death

Question 24

Outline the control of lice

Answer 24

• Spread by direct contact so limit
• Adults, nymphs and eggs only survive few days off host
• Control uncomplicated as most time on host
• Need to consider sucking vs chewing, timing and treatment method
• Treat all animals at once
• Spot ons, pour ons, powers

Question 25

Describe the appearance of Felicola subrostratus

Answer 25

- Distinct triangular head - Legs for grasping - Thorax - Large rounded abdomen, pointy at end

Question 26

Describe the appearance of Linognathus

Answer 26

- Thin pointed head - More rounded legs - Elongated/oval abdomen -

Question 27

Describe the appearance of chewing lice

Answer 27

- Flat/rounded head | - Mouthparts less obvious

Question 28

Describe the appearance of Haematopinus suis

Answer 28

- Similar to Felicola - Claws obvious on feet - Dots around outside of abdomen