Phthiraptera: Ischnocerca and Anoplura

Question 1

Tell me about Ischnocera (Mallophaga)

Answer 1

Biting, chewing lice
Wide mandable mouthparts
Feed on skin, hair, feathers, other organic material
3mm, yellow
Rapid movement to move over skin and covering
Often bird lice

Question 2

Trichodectes canis Common Name:

Answer 2

Dog Biting Louse or Canine Chewing Louse

Question 3

Trichodectes canis Host:

Answer 3

Dogs: VERY HOST SPECIFIC

Question 4

Trichodectes canis Identification:

Answer 4

Yellowish color, biting/chewing mouthparts, active louse, adults 2mm.
Really host specific

Question 5

Trichodectes canis Life Cycle:

Answer 5

Females lay whitish eggs (“nits”), which develop to adults in a month. Eggs hatch to nymphs, and after 3 molts fully grown adults are present.
Requires the host to complete life cycle. Lice are active on host

Question 6

Trichodectes canis Site of Infection:

Answer 6

Hair, skin, edge of ears

Question 7

Trichodectes canis Pathogenesis and lesions

Answer 7

Vector of Dipylidium caninum.

Heavy infestations of lice found in animals neglected and underfed. Young are most affected.

Question 8

Trichodectes canis Clinical Signs:

Answer 8

Causes pruritus. Dog scratches causing self inflicted injury, loss of hair.
In heavy combined infestations (with Linognathus, another louse species) anemia can occur<— (she mentioned this in class, not to get confused: Trichodectes canis does not cause anemia by itself, could be a question)
Dogs are restless and scratch continuously

Question 9

Trichodectes canis Diagnosis:

Answer 9

Identification of Louse

Question 10

Trichodectes canis Treatment and Prevention:

Answer 10

Springer and Cocker Spaniels; Afghans are more disposed to infestations
Transmission is by direct dog to dog contact and direct transfer to nymph and adult stages with brushes, combs and blankets. Appropriate insecticides are carbaryl-containing shampoo, spray, or dip. Pyrethroids, imidacloprid and some MCLs also are effective

Question 11

Tell me about Suborder Anoplura

Answer 11

Bloodsucking lice, more pathogenic
Pointed "noses"
Large, 3-5 mm
Dark blue, depending on amount blood ingested
Slow moving
Clasping hair shaft
Lice of mammals: grasp on the hair shaft

Question 12

Linognathus setosus Common Name:

Answer 12

Dog sucking louse

Question 13

Linognathus setosus Hosts:

Answer 13

Dogs

Question 14

Linognathus setosus Identification:

Answer 14

Adult, wingless, 3-5 mm, head narrower than thorax, sucking mouthparts. Flattened dorsoventrally, slate gray. Nymphs similar to adults but smaller

Question 15

Linognathus setosus Life cycle:

Answer 15

Female attach eggs (“nits”) to hair, which develops to adults in a month. Egg hatches to nymphs, and after 3 molts fully grown adults are present. Requires the host to complete life cycle. Nymphs and adults can live off their hosts for only a few hours. Whole cycle is 2-4 weeks

Question 16

Linognathus setosus Site of Infection:

Answer 16

Skin

Question 17

Linognathus setosus Pathogenesis and lesions

Answer 17

Heavy infestation can cause severe anemia

Question 18

Linognathus setosus Clinical Signs:

Answer 18

Loss of body condition and damage to skin

Question 19

Linognathus setosus Diagnosis:

Answer 19

Louse Identification

Question 20

Linognathus setosus Treatment and prevention

Answer 20

Transmission is by direct contact with brushes, combs and blankets. Appropriate insecticides are carbaryl-containing shampoo, spray or dip