Week 2: Mites - COMPLETE *****

Question 1

State the Class for Mites
- State their subclass
- Which other species do they share this subclass with?

Answer 1

arachnida

acari

ticks

Question 2

Anatomy: How many legs do adults have?
- How many legs do nymphs have?
- How does their body differ to insects? 2

Answer 2

8

6

it is non-segmented
it consists of 2 sections not 3

Question 3

Are all mites parasitic?
- What is a mite infestation called?
- What is the clinical name for a severe mite infestation?

Answer 3

no most mites are free living and non-parasitic

acariasis

mange

Question 4

How long is their life cycle?
- What 2 major groups can you split mites into?

Answer 4

1-4 weeks

surface mites and burrowing mites

Question 5

Surface Mites: State the name of a very significant mite with several strains affecting several hosts
- How do we name this mite differently for different species strains? e.g. for sheep
- why is this mite so damaging?

Answer 5

psoroptes

as ovis to the end for sheep

it causes severe irritation causing rubbing and subsequent trauma

Question 6

Surface mites: Which mite causes sheep scab?
- What type of reaction is this to the mite?
- Is this a notifiable disease?

Answer 6

psoroptes ovis

hypersensitivity reaction and self trauma

no but it used to be

Question 7

Surface Mites: Which mite can be found in the ear of rabbits?

Answer 7

psoroptes cuniculi

Question 8

Surface Mites: Which mite is responsible for being the most common cause of mange in cattle and horses? (especially in the winter)
- Where on the body is often infested and what does this cause?
- Where might you find an infestation of a horse?
- What about in a cow?

Answer 8

chorioptes bovis

in localised areas causing lesions

on the lower legs

in the tail and perineum area

Question 9

Surface Mites: State the most common ear mite in cats and dogs
- what clinical signs does it cause? 4
- what are the risks if left untreated?
- is it always clinical presentation?
- how can you diagnose them? 2

Answer 9

otodectes cynotis

thick red crusts in the external ear
head shaking
ear scratching
ear droop

the infection could spread to the inner ear

often subclinical

using an otoscope
or wax smear on slide for microscopic examination

Question 10

Surface Mites: What is the most common surface mite to infect domestic fowls?
- What do they eat?
- What clinical signs would you expect to see in mild cases?
- What could happen in severe cases and why?

Answer 10

dermanyssus gallinae

a blood meal at night

loss of condition

death due to anaemia

Question 11

Burrowing Mites: Name the 3 mites under the Sarcoptidae genus

Answer 11

sarcoptes
trixacarus
notoedres

Question 12

Burrowing Mites: Which burrowing mite causes intense pruritus and has strains to affect most mammals?
- is it contagious?
- Why does it cause intense pruritus?
- How can you diagnose it?

Answer 12

sarcoptes scabei

yes

due to hypersensitivity to mite faecal material

deep skin scraping in 12 or more affected sites

Question 13

Burrowing Mites: Which burrowing mite affects guinea pigs?
- What clinical signs might you see? 3
- How can you diagnose it? 2

Answer 13

trixacarus caviae

pruritus
alopecia
dermatitis

examination of hair shafts
skin scrapings

Question 14

Burrowing Mites: Which burrowing mite affects cats?
- What clinical signs would you expect to see? 3
- Where on the cat is it most commonly found? 2

Answer 14

notoedres cati

pruritus
alopecia
dermatitis

on the head
around ears

Question 15

Burrowing Mites: Which burrowing mite affects birds?
- What conditions is it usually responsible for? 2
- What clinical signs would you expect to see? 5

Answer 15

knemidocoptes

scaly face
scaly foot

pruritus
lameness
hyperkeratosis
inflammation
dried exudate

Question 16

Burrowing Mites: Which burrowing mite lives particularly in the hair follicles of domestic animals?
- can it be found on healthy animals?
- Which animal is it most commonly seen in?

Answer 16

demodex

yes it is a normal commensal in low numbers

dogs

Question 17

Burrowing Mites: Demodex Canis
- If you identify an infestation in a dog, what else should you suspect?
- What is an infestation often secondary to?
- is it localised or generalised?

Answer 17

an underlying disease

staphylococcal pyoderma

it can be either

Question 18

Burrowing Mites: Demodex Canis
- If localised, where would you expect to find it?
- is a localised or generalised infection more severe?
- Which one is more indicative of an underlying disease?
- How can you diagnose it?

Answer 18

on the face and forelegs

generalised

generalised

by a hair pluck or skin scrape

Question 19

Veterinary Significance: What are the direct effects of mite infestations on an animal? 3

Answer 19

direct epidermal damage
production of cutaneous hypersensitivity
loss of blood or other fluids

Question 20

Veterinary Significance: Direct effects
- What types of lesions indicating epidermal damage could you see? 5

Answer 20

skin erythema
pruritus
scale formation
lichenification
crust formation

Question 21

Veterinary Significance: What is the biggest indirect effect of mites?

Answer 21

mechanical or biological transmission of pathogens

Question 22

Control: What drug groups can be used to treat affected animals?
- What other things can you do to help affected animals?
- What should you do to ‘in-contact’ animals?
- Which mite is not contagious?

Answer 22

isoxazolines

clip fur
treat with keratolytic shampoo to remove crusts

treat them if the mite is potentially contagious even if asymptomatic

demodex canis

Question 23

Control: What can you do to the environment, especially for poultry mites? 2

Answer 23

physically clean the environment
use of miticidal agents