Dogs & Cats: Ticks, Lice (Exam 1)

Question 1

What tick has (1) long mouth parts and (2) an inornate scutum?

Answer 1

Ixodes

Question 2

What tick has (1) long mouth parts and (2) an ornate scutum?

Answer 2

Amblyomma

Question 3

What tick has (1) short mouth parts and (2) an ornate scutum?

Answer 3

Dermacentor

Question 4

What tick has (1) short mouth parts and (2) an inornate scutum?

Answer 4

Rhipicephalus

Question 5

Amblyomma: Ornation and Mouthparts

Answer 5

Ornate with long mouthparts

Question 6

Ixodes: Ornation and Mouthparts

Answer 6

Inornate with long mouthparts

Question 7

Rhipicephalus: Ornation and Mouthparts

Answer 7

Inornate with short mouthparts

Question 8

Dermacentor: Ornation and Mouthparts

Answer 8

Ornate with short mouthparts

Question 9

What is included in Phthiraptera?

Answer 9

Chewing and sucking lice

Question 10

What are the 4 suborders of Phthiraptera? Are they chewing or sucking?

Answer 10

Chewing: amblycera, ischnocera, rhynchophthirina (wide heads)
Sucking: anoplura (narrow heads)

Question 11

Morphology of Lice (general)

Answer 11

Wingless
Dorsoventrally flattened
Reduced eyes or none
Tarsal claws often enlarged for clinging to hairs and feathers

Question 12

Morphology of Lice (chewing)

Answer 12

Small in size
Head usually broader than prothorax and lack ocelli (eye-like structure)

Question 13

Chewing Lice: Diagnosis

Answer 13

Eggs are laid and cemented at the base of feathers and hairs

Question 14

Chewing Lice: Location/Hosts

Answer 14

Birds and mammals
Feed on feathers and hair, occasionally eating sebaceous secretions, mucous sloughed epidermis or blood
May vector filarial nematodes
Highly adapted to parasitism
No free-living stages

Question 15

Sucking Lice: Morphology

Answer 15

Heads narrower than prothorax
Legs have a single tarsal claw for clinging to hairs

Question 16

Who do sucking lice parasitize?

Answer 16

Only mammals

Question 17

Flea Morphology

Answer 17

Bilaterally flattened
Wingless
Usually tan or yellow in color, may be reddish brown
Larvae not parasitic (feed on debris and material in the nest or surroundings)
Legs are strong and hind legs usually larger (for jumping)

Question 18

Flea: Development

Answer 18

Adults often oviposit on host, but are not sticky and fall into environment
High humidity favors egg laying

Question 19

Steps of Flea Development

Answer 19

Flea eggs –> larvae –> pupae –> adult flea

Question 20

Tick & Mite: General Characteristics

Answer 20

All ticks are epidermal parasites
Larval, nymphal, adults
“Instars” = young
Mites may life in skin, respiratory system
Ubiquitous

Question 21

Tick & Mite: Morphology

Answer 21

Tagmatization reduced to 2 body regions
Head and thorax are fused
Dorsoventrally flattened

Question 22

Tick Morphology

Answer 22

4 pairs of legs
No antennae
Sexual dimorphism
Females have scutum that covers only part of abdomen, males have scutum that covers entire abdomen

Question 23

Tick Life Stages

Answer 23

Egg –> larvae –> nymph –> adult

Question 24

Tick Life Cycle

Answer 24

Can range from a few weeks to a few years
Differ in number of immature stages (instars)

Question 25

Hard v Soft Tick Instars

Answer 25

Hard ticks (Ixodidae): 1 nypmhal stage
Soft ticks (Argasidae): up to 5 nymphal stages

Question 26

Tick Reproduction

Answer 26

Occurs on host
Blood meal important for laying eggs, which is done after female drops off into environment
Cannot fly or jump, only crawl

Question 27

Hard Tick life Stages

Answer 27

Eggs –> 6-legged larva –> 8-legged nymph –> 8-legged adult

Question 28

Tick Environmental Factors

Answer 28

Hardy in environment
Can withstand months without feeding
May need to sit and wait for host
Detects host using olfaction and variety of cues (humidity, temp, CO2)

Question 29

What are the (5) tick species common in north america?

Answer 29

American dog tick (dermacenter variabilis)
Lone star tick (amblyomma americanum)
Black-legged tick/deer tick (ixodes scapularis)
Brown dog tick (rhipicephalus sanguineus) - can establish indoors
Winter tick (dermacentor albipictus)

Question 30

What are the direct and indirect effects of ticks as vectors of disease?

Answer 30

Direct: blood loss/anemia, inflammation/pruritus, toxicosis
Indirect: disturbance/annoyance, vectors of other agents