lice

Question 1

discuss physical adaptations of lice (phthiraptera)

Answer 1

• claws
• dorso-ventrally flattened
• wingless
• mouthparts are either adapted for chewing or sucking

Question 2

describe louse eggs

Answer 2

• pale
• translucent
• suboval
• usually firmly glued to the hairs near to the skin
• chicken lice laye their eggs in large masses at the base of feathers

Question 3

discuss the lifecycle of lice

Answer 3

1. adult lays eggs (nits)
2. nits hatch into nymphs
3. nymphs moult until reach adult size

the whole cycle takes 3-4 weeks to complete depending on the species

Question 4

are you likely to get infected with chicken lice as a human? why or why not

Answer 4

no - lice are highly specialised blood sucking parasites who undergo many generations on one host. transmission is usually through close contact. most lice have evolved to live on a single or limited host range

Question 5

what is pediculosis

Answer 5

an infestation of lice

Question 6

what are the clinical signs or pediculosis

Answer 6

• pruritus and dermal irritation
• unthrift appearance
• rough coat
• lowered production in farm animals
• in severe infestations, loss of hair and local scarification
• extreme infestation with sucking lice can cause anemia, and wounds that can become infected

Question 7

what is a common disease seen in animals spread by lice

Answer 7

swine pox spread by the pig louse

Question 8

discuss why lice on birds is a welfare concern

Answer 8

• not highly pathogenic on adults but can kill chicks
• damage to the skin may lead to secondary bacterial infections
• irritation leading to restlessness, feather damage, feather plucking, cessation of feeding and death

Question 9

discuss how you would identify a specific species of lice

Answer 9

usually can narrow down based on host

Question 10

what are the 2 types of sucking lice and which host species will you find them

Answer 10

haematopinus: pigs, cattle and horses
linognathus: cattle, sheep, goats and dogs

Question 11

is damalinia chewing or sucking lice? where will you find them

Answer 11

chewing
- cattle
- sheep
- goats
- horses

Question 12

where will you find felicola

Answer 12

cats

Question 13

where will you find trichodectes

Answer 13

dogs

Question 14

what species of lice will be found on birds

Answer 14

chewing lice only
- lipeurus
- cuclotogaster
- menacanthus

Question 15

what species of lice are found on guinea pigs

Answer 15

• gliricola
• gyropus

Question 16

how can you tell the difference between haematopinus and linognathus

Answer 16

haematopinus have 6 legs which are all the same length whereas linognathus have shorter front legs

Question 17

what species of lice is this and how do you know

Answer 17

haematopinus
- legs all the same length
- know it is sucking lice because mouth part is quite pronounced

Question 18

what species is this and how do you know

Answer 18

linognathus
- front legs smaller
- know it is sucking because pronounce mouth parts

Question 19

how would you apprach treatment of lice

Answer 19

• is the lice sucking or biting?
• consider the timing of the lifecycle, most treatments only kill adults or nymphs and not eggs, treat to kill adults and again to kill hatched nymphs
• treat all animals that have contact