Exam II - Order Acari - Mites

Question 1

Describe the different strategies utilized by Order Acari

Answer 1

• Burrow into the host epidermis (Sarcoptes)
• Non-burrowing, entirely on skin surface (Cheyletiella, Chorioptes)
• Restricted to an area of the body (Otodectes)

Question 2

What is the common name for Sarcoptes scabiei?

Answer 2

Sarcoptic mane mite, itch mite, scabies mite

Question 3

What is the scientific name for the Sarcoptic Mange Mite?

Answer 3

Sarcoptes scabiei

Question 4

What is/are the host(s) for Sarcoptes scabiei?

Answer 4

All domestic animals and humans.

It is rare in cats

Question 5

Describe the appearance of the Sarcoptes scabiei adult

Answer 5

round, 500 um diameter, short legs, suckers on long unsegmented stalks differ between sexes

Question 6

How many weeks can Sarcoptes scabiei live on the surface of the skin?

Answer 6

Trick question! Sarcoptes scabiei is a burrowing mite. It can NOT live on the surface of the skin.

Question 7

What is the PPP for Sarcoptes scabiei?

Answer 7

2-3 weeks

Question 8

Describe the life cycle of Sarcoptes scabiei

Answer 8

Fertilized female tunnels in upper layers of epidermis, feeding on damaged tissue. Eggs are laid in tunnels & hatch in 3-5 days to larvae that crawil on skin surface.

Larvae burrow and form molting pockets where nymphs and adults develop.

All stages tunnel in the epidermis, resurface, and burrow again. Adult male emerges and seeks female. After fertilization, the process starts over.

Question 9

Where do Sarcoptes scabiei nymphs and adults develop?

Answer 9

**molting pockets **in the host’s skin

Question 10

What is/are the site(s) of infection for Sarcoptes scabiei?

Answer 10

Skin.

Question 11

Describe any pathogenesis associated with Sarcoptes scabiei

Answer 11

Erythema, scale and crust formation

Question 12

Describe some clinical signs associated with Sarcoptes scabiei

Answer 12

Begins on hairless areas of body (lateral elbow & pinna of the ear are common starting places)

Lesions of follicular papules, erythema, crusts of dried serum and blood, and pruritus

Question 13

How would you diagnose Sarcoptes scabiei?

Answer 13

Skin scraping, but recovery of the mite is difficult

Question 14

Describe treatment and prevention options for Sarcoptes scabiei

Answer 14

MCLs are effective, treatment of pets cure the humans they infest.

This is very contagious, so treat all of the animals in the household

Question 15

What is the common name for Demodex canis?

Answer 15

Demodectic mange mite, follicle mite

Question 16

What is/are the host(s) for Demodex canis?

Answer 16

Dogs.

Question 17

Describe the appearance of the Demodex canis adult

Answer 17

Cigar with Legs

Adults have elongate tapering body, 400 um, 4 pairs of stumpy leggs on anterior

Question 18

Describe the life cycle of Demodex canis

Answer 18

Entirely in hair follicles and sebaceous glands. Mites are normal fauna of skin. Adults in follicles lay eggs, larvae and nymphs at mouth of follicle. Egg to adult in 2-4 weeks.

Transmission to newborn pups is from bitch to pup by direct contact during nursing in first 2-3 days postpartum

Question 19

What is/are the site(s) of infection for Demodex canis?

Answer 19

Hair follicles and sebaceous glands

Question 20

Describe any pathogenesis associated with Demodex canis

Answer 20

The presence of small numbers of mites is normal.

In larger numbers of mites, we may see localized demodicosis associated with alopecia, erythema and no pruritis.

Prognosis for recovery is excellent

Question 21

What is the first clinical sign you will notice in localized demodicosis?

Answer 21

alopecia

Question 22

How would you diagnose Demodex canis?

Answer 22

Skin scrapings can revel the mite, BUT presence does not necessarily indicate disease since these are normal inhabitants of the dog

Question 23

Describe generalized demodicosis

Answer 23

characterized by 5 more more areas of localized disease or entire body region, hair sparse and skin coarse and dry, develops to “red mange”.

Concomitant staphylococcal pyoderma develops, pustules develop, open, and ooze. Very difficult to cure

Question 24

Describe treatment & prevention options for generalized demodicosis

Answer 24

Amitraz (formamidine) is approved

Question 25

What is the common name for *Cheyletiella yasguri?*

Answer 25

Walking dandruff

Question 26

Who is/are the host(s) for *Cheyletiella yasguri*?

Answer 26

dogs, humans

Question 27

Describe the appearance of the *Cheyletiella yasguri* adult

Answer 27

Body has a "waist", legs long, 500 um. Called "walking dandruff because large enough to be seen walking against a dark background, prominent palpal claws

Question 28

What is/are the site(s) of infection for *Cheyletiella yasguri*?

Answer 28

Fur and hair

Question 29

Describe the life cycle of *Cheyletiella yasguri*

Answer 29

Mites live on skin, hair and tunnel in epidermis debris. Mites feed on debris. Eggs attached to hair. Transmission is by direct contact. Life cycle is completed in 2 weeks.

Question 30

How would you diagnose *Cheyletiella yasguri*?

Answer 30

dandruff. Exam of an adhesive tape swap may reveal mites also

Question 31

What are the treatment options for *Cheyletiella yasguri*?

Answer 31

insecticides

Question 32

What is the scientific name for "walking dandruff"

Answer 32

*Cheyletiella yasguri*

Question 33

What is the common name for *Otodectes cynotis?*

Answer 33

ear mite

Question 34

What is/are the host(s) for *Otodectes cynotis*?

Answer 34

Dogs, cats, ferrets, & foxes

Question 35

Describe the appearance of the *Otodectes cynotis* adult

Answer 35

500 um in length. Long legs extending beyond body margin, suckers of males and females differ, copious dark cerumen is observed. Here are two now... having sex:

Question 36

What is/are the site(s) of infection for *Otodectes cynotis*?

Answer 36

Ears.

Question 37

Describe any pathogenesis associated with *Otodectes cynotis*

Answer 37

In cats: dry, waxy parchment-like material in ears with large numbers of mites. Can lead to secondary infections resulting in external ear inflammation (otitis externa)

Question 38

What clinical sign should you look for with *Otodectes cynotis*

Answer 38

frequent shaking of head

Question 39

How would you diagnose *Otodectes cynotis*?

Answer 39

Behavior of the animal, exudate in ear canal, mites on slide

Question 40

What are some treatment options for *Otodectes cynotis*?

Answer 40

Ivermectin otic suspensions, revolution, and other compounds are approved