Parasitology: Other Insects and Acarines

Question 1

How many body parts do ticks and mites have?

Answer 1

2

Question 2

What are the body parts of ticks and mites?

Answer 2

• Idiosoma (body)

- gnathosoma (mouth)

Question 3

Ticks and mites have what kind of metamorphosis.

Answer 3

incomplete, the larvae appear similar to the adult

Question 4

How do you determine between a parasitic mite and a non-parasitic mite?

Answer 4

identify structures on the mite that appear to be adaptations for being on animals (suckers, claws, plungers, etc.)

Question 5

How does knowing what types of mite you will see on an animal determine if an infestation is present?

Answer 5

you can determine if the parasite is truly an infestation or if its just something the animal ate

Question 6

What is mange?

Answer 6

a skin disease of domestic animals cause by a number of genera of mites

Question 7

Is there a characteristic skin lesion associated with mange?

Answer 7

no

Question 8

Can mange lead to pyorderma?

Answer 8

yes

Question 9

What is Scabies?

Answer 9

a type of mange that refers to an infestation of Sarcoptes spp., but is sometimes used more generally

Question 10

What is the typical life cycle of a mite?

Answer 10

• all stages on host (poor survival off of host)

- short life cycle (a few weeks)

Question 11

T/F: Mites tend to be host-specific

Answer 11

True (there are some exceptions)

Question 12

How are mites transmitted?

Answer 12

direct contact or fomites

Question 13

How does one diagnose a mite infestation?

Answer 13

skin scraping at periphery of lesion

Question 14

T/F: an animal can be infested with mites, yet not show any clinical signs

Answer 14

true

Question 15

What are examples of typical mites:

Answer 15

• Sarcoptes
• Knemidocoptes
• Demodex
• Otodectes
• Chrioptes
• Psoroptes

Question 16

What are some examples of atypical mites?

Answer 16

• Trombiculids (chiggers)
• Dermanyssus
• Ornithonyssus

Question 17

What are some examples of subsurface mites

Answer 17

• Sarcoptes
• Knemidocoptes
• Demodex

Question 18

What are some examples of surface mites?

Answer 18

• Otodectes
• Chrioptes
• Psoroptes
• Trombiculids
• Dermanyssus
• Ornithonyssus

Question 19

Is Sarcoptes a subsurface or a surface mite?

Answer 19

subsurface

Question 20

Physical appearance of Sarcoptes scabiei.

Answer 20

• typical parasitic mite
• round body
  last 2 pairs of legs are short

Question 21

Where do female Sarcoptes lay eggs?

Answer 21

in tunnels they burrowed into the epidermis

Question 22

How long is the general life cycle of Sarcoptes Scabiei?

Answer 22

about 3 weeks

Question 23

T/F: Sarcoptes Scabiei can infest humans.

Answer 23

False, they can cause lesions, but they can’t infest you

Question 24

Are there any cross-infections of Sarcoptes between species

Answer 24

no

Question 25

What are some hosts of Sarcoptes

Answer 25

- common hosts: dogs and pigs | - uncommon hosts: horses and cattle

Question 26

Clinical importance of Sarcoptes scabiei in dogs.

Answer 26

- can cause intense pruritis, which can lead to self-inflicted trauma, and potentially a secondary bacterial infection

Question 27

What are some signs of chronic sarcoptic infestation?

Answer 27

- alopecia, thickened, wrinkled skin - secondary bacterial infection - self inflicted trauma

Question 28

where do mites prefer to attempt to feed?

Answer 28

- hairless or thin-haired area | (you might see lesions first appear on face, ears, legs

Question 29

How does one diagnose Sarcoptes in dogs?

Answer 29

- skin scrapings (several locations) | - fecal exams (may find mites or eggs)

Question 30

If there are multiple animals within the household, which do you treat for Sarcoptes?

Answer 30

all animals

Question 31

Do you need to treat the environment when treating for Sarcoptes

Answer 31

nope, just wash the bedding, clean the kennel

Question 32

Can your dog's Sarcoptes infestation affect your cat?

Answer 32

yes, in that you may see transient lesion. no, it will not infest your cat

Question 33

T/F: there is a Sarcoptic mite of cat with a different genus.

Answer 33

true

Question 34

What other animals can you see sarcoptic mites on?

Answer 34

- guinea pigs, foxes

Question 35

What animals do Knemidocoptes affect?

Answer 35

poultry and pet birds

Question 36

What is a more common name for Knemidocoptes?

Answer 36

scaly leg mite scaly face mite (depends on where the lesion is)

Question 37

Where do you most commonly see Knemidocoptes infestations?

Answer 37

mostly on nonfeathered portions of the body

Question 38

What is a characteristic lesion appearance for Knemidocoptes infestations?

Answer 38

a honeycomb appearance

Question 39

Describe general Demodex spp characteristics

Answer 39

- typical subsurface mite - usually parasitize hair follicles or sebaceous glands - elongated in appearance, legs on anterior end

Question 40

Is Demodex host species-specific?

Answer 40

yes

Question 41

T/F: Some animals have more than 1 Demodex species

Answer 41

True

Question 42

T/F: Common species of demodex can be though of as normal skin fauna

Answer 42

true, transmission occurs shortly after birth from dam

Question 43

Which species of host is Demodex most important in?

Answer 43

dogs

Question 44

When do clinical sign of Demodex infestation appear?

Answer 44

when mites proliferate beyond normal levels. The balance between host and mite shifts to favor the mite

Question 45

How does a Demodex infestation affect the host's body?

Answer 45

- interferes with follicle, gland function | - can lead to inflammation, secondary infection

Question 46

What are the 2 forms Demodecosis appears in with dogs?

Answer 46

- Localized form | - generalized form

Question 47

What is the localized form of Demodecosis in dogs?

Answer 47

- the immune response is still developing - affects puppies 3-10 mo. of age - can see small, hairless regions - does not cause itching

Question 48

about how many cases of localized Demodecosis resolve spontaneously?

Answer 48

90%

Question 49

What is the generalized form of Demodecosis in dogs?

Answer 49

- occurs due to specific immune deficiency - can be caused by either a progressive spread from localized form in pups OR by adult onset - more often seen in purebred shorthaired dogs

Question 50

How do you diagnose Demodex?

Answer 50

- skin scrapings

Question 51

Where would you find eggs and mites of Demodex?

Answer 51

feces

Question 52

What are the general characteristics of surface mites?

Answer 52

more ovular than Sarcoptic mites, have longer legs

Question 53

What is the minimum length of the surface mite life cycle

Answer 53

2 weeks

Question 54

What are some examples of surface mites?

Answer 54

- Otodectes - Chorioptes Psoroptes

Question 55

What is the worldwide parasite of ear canals in dogs, cats, and ferrets

Answer 55

Otodectres cynotis

Question 56

In which species do you most often see Otodectes cynotis

Answer 56

cats

Question 57

What is a major clinical sign of an Otodectes infestation?

Answer 57

intensely pruritic otitis externa | - The exudate looks like coffe grounds in ear

Question 58

How do you diagnose Otodectes

Answer 58

ear swab and microscopic Identification

Question 59

how do you treat Otodectes cynotis

Answer 59

clean the ear and use a miticide

Question 60

What is the most often encountered large animal mite in the US?

Answer 60

Chrioptes spp

Question 61

Which animals are affected by Chorioptes spp.? Which animal is the most frequently affected?

Answer 61

- ruminants, horses (spp. are host-specific) | - cattle

Question 62

Predilection site of Chorioptes in cattle

Answer 62

- tailhead (common) - udder - perineal region

Question 63

Predilection site of Chorioptes in small ruminants

Answer 63

- leg | - lower body

Question 64

Predilection site of Chorioptes in Horses

Answer 64

- legs, esp. Feathered horses

Question 65

What do Psoroptes ovis and bovis cause in their hosts?

Answer 65

- severe pruritis and skin lesions

Question 66

how do you diagnose a Psoroptes infestation?

Answer 66

skin scrapings

Question 67

Is a Psoroptes infestation reportable?

Answer 67

yes

Question 68

Are Trombiculids host-specific?

Answer 68

no

Question 69

Which stage of the trombiculid lifecycle is parastic?

Answer 69

larvae

Question 70

Where would one get a trombiculid infestation?

Answer 70

the environment

Question 71

What is the issue with a trombiculid infestation?

Answer 71

the pruritis persists after the mite has gone, so you might end up treating the symptom, not the cause

Question 72

What group do chiggers and harvest mites fall into?

Answer 72

Trombiculids

Question 73

How are Trombiculid infestations diagnosed?

Answer 73

visual confirmation of red or orange mites, especially on face, ears in dogs and cats

Question 74

Treatment of Trombiculid infestations

Answer 74

acaricidal treatments if mites are present

Question 75

What is the importance of Mesostigmatid mites

Answer 75

They're the bird mites

Question 76

Are mesostigmatid mites larger or smaller than most parasitic mites

Answer 76

larger

Question 77

What is the scientific name of the northern fowl mite?

Answer 77

Ornithonyssus sylviarum

Question 78

what are some clinical signs associated with O. sylviarum infestation?

Answer 78

- decreased weight gain | - egg production issues

Question 79

Where does O. sylviarum life stages typically occur

Answer 79

all life stages on host

Question 80

How does Dermanyssus differ from O. sylviarum parasitically

Answer 80

Dermanyssus only visits host to feed, can be zoonotic O. sylviarum stays on host