Parasitic Skin Disease I Flashcards
(49 cards)
1
Q
What are the two different types of Endoparasites?
A
- Protozoa
- Helminths
2
Q
What are the two different components of arthropods
A
Arachnids and Insects
3
Q
What are the 4 types of Insects?
A
- Flies (Diptera)
- Anoplura (Sucking Lice)
- Mallophaga (chewing or biting lice)
- Fleas (Siphonaptera)
4
Q
What does metameric mean?
A
divided into segments
5
Q
What are five features of arthropods?
A
- Metameric
- Contains over 80% of all known animal species
- Possess a hard chitinous exoskeleton and moults during development
- Segmented body and jointed limbs
- Separate sexes so mating is required
6
Q
What is a nymph?
A
The immature form of an insect, looks like the adult but smaller
7
Q
What is larva?
A
Immature form of an insect but with a different morphology
8
Q
What is the difference between soft and hard ticks in the life cycle?
A
Hard ticks molt from a nymph to an adult and always feed on blood
Soft ticks can molt from a nymph to another nypmh and dont always feed on blood as adults
9
Q
How long does the full mite lifecycle take approximately?
A
Around 2-3 weeks
10
Q
What are some examples of Burrowing Mites?
A
Sarcoptes, Demodex, Notoedres
11
Q
What are some examples of non-burrowing mites?
A
Psoroptes, Chorioptes, Otodectes
12
Q
What type of mites have shorter legs?
A
Burrowing
13
Q
List 5 key facts about sarcoptes scabei
A
- Burrowing Mite
- Can affect all domestic animals and humans (is therefore zoonotic)
- The female adult mates and then digs into the epidermis
- Lays 2-4 eggs a day
- Causes sarcoptic Mange
14
Q
List 5 key facts about sarcoptic mange
A
- Transmitted via close contact
- caused by the burrowing damage of mites plus the release on antigenic substances in mite saliva/faeces
- Causes intense itching and self-inflicted trauma/ pruritus
- Can cause hide damage in production animals
- Welfare issue
15
Q
List 6 key facts about Demodex
A
- Burrowing Mite
- Cigar shaped with 8 legs
- Lives in the hair follicles and sebaceous glands of the skin
- Lifecycle usually takes around 3 weeks
- Usually a harmless commensal of the skin
16
Q
What is the name of the mite that causes demodecosis?
A
Demodex
17
Q
List 5 key facts about demodecosis
A
- Also called demodectic mange
- can lead to generalised demodicosis
- itchy if the mite numbers are high
- Can look like a localised area of alopecia
- Usually goes along with generalised disease
18
Q
What type of mite is psoroptes ovis and what does it cause?
A
Non-Burrowing Mite that causes sheep scab
19
Q
List 5 key facts about psoroptes ovis
A
- The mouthparts abrade the skin
- Intense itching and wool loss (sheep scab)
- Can be fatal if left untrested
- Notifiable disease in scotland
- Not Zoonotic
20
Q
List 5 key facts about Chorioptes bovis
A
- Causes localised or generalised mange
- Most common in cattle and horses
- Non-Burrowing Mite
- Highland cattle are the most prone
- It is less pathogenic than psoroptes
21
Q
List 5 key facts about Otodectes cyanotis
A
- Non-Burrowing Mite
- Mainly in Cats and Dogs
- Very Common
- Inhabits deep inside the ear canal
- Produces a dark dry discharge from inside the ears and causes itching
22
Q
List 5 key facts about Cheyletiella
A
- Non-burrowing Mite
- Common in Rabbits, Cats and dogs
- Causes Excessive scale and slight itchiness
- Very Motile/ can walk
- Zoonotic
23
Q
List 5 key facts about Dermanyssus spp.
A
- Non-Burrowing
- Red Mite of poultry
- Blood feeders (they are grey before feeding)
- The eggs are laid off the host, they have a short lifecycle
- Can Bite Humans
24
Q
What burrowing mite is usally a harmless commensal of the skin?
A
Demodex
24
What kind of ecotoparasites are hard ticks?
| temporaryor non temporary
Temporary, this means they drop off and live in the environment
25
During what seasons are hard ticks active and inactive?
They are usually inactive in the winter, they increase activity in the spring and early summer so they can feed
activity then reduces in the peak summer and there is a second peak of activity in the autumn
26
What are the two most common tick species in the UK?
* Ixodes ricinus
* I.hexagonus
27
What kind of climates do soft ticks tend to live in?
Warmer/ More tropical climates
28
When are soft ticks mostly active?
They are mostly active at night
29
Name 5 acaricides for mite and tick treatment
* Moxidectin
* Fipronil
* Amitraz
* Afoxolaner
* Flumethrin
30
What is the lifecycle of Mites?
* They undergo simple metamorphosis with both the larval and nymphal stages resembling adults
* They have two distinct sexes with females laying eggs **on** the host
* Larva then hatches, may or may not feed and then molts to a nymph
* Nymph then feeds and molts to another nymph or adult
* They tend to spend their entire lifecycle on the host, transmission is usually via direct contact
31
What is the lifecycle of ticks?
* Simple metamorphosis with both larval and nymphal stages resembling adults
* Separate sexes with females laying eggs **off** the host
* Larva hatches, feeds on the host then moults to a nymph
* Nymph feeds on the host and then moults to another nymph
* All adult hard ticks feed on blood but not all adult soft ticks do
32
How long is the average mite lifecycle?
2-3 weeks
33
Where does demodex live in the skin?
Lives in hair follicles and sebaceous glands
34
What does psoroptes ovis cause?
'sheep scab' or psoroptic mange
35
How does psoroptes trigger an allergic response?
Mouthparts abrade the skin and contaminate it with mite faeces -> goes on to cause an allergic response
36
What are the clinical signs of psoroptes ovis?
intense itching and wool loss
37
What mite is a notifiable disease in scotland?
Psoroptes ovis
38
What cattle are more prone to chorioptes bovis?
Highland cattle are more prone due to being in a microclimate
Chorioptes is *less pathogenic* than psoroptes
39
Where does otodectes cyanotis inhabit?
Deep inside the ear canal of mainly cats and dogs, produces a dark brown/ dry discharge and causes itching
40
What species does cheyletiella usually inhabit?
Rabbits, cats and dogs
It is very motile and usually called 'walking dandruff'
41
What mite is a blood feeder, usually found on birds that is also known to bite humans
Dermanyssus spp.
42
What are the most common tick type in the UK?
Hard ticks (with the chitinous dorsal plate also known as a scutum)
43
What is the average lifecycle of the hard tick?
* Blood feeding occurs at each stage
* Once fed (around 1-2 weeks) they drop off and live in the environment
* The adult female feeds to obtain protein in the blood for her eggs and can swell to 2-3 times her original size
44
When are hard ticks usally inactive?
Normally inactive in the winter, they feed in the spring and early summer, there is an activity reduction in summer and a second activity peak in autumn
45
What are the most common hard tick species in the UK?
Ixodes ricinus, I. hexagonus
46
Where are soft ticks most commonly found?
Usually live in warm/ tropical climates
They undergo one larval and several nymph stages
More drough tolerant than hard ticks
Mostly active at night
Live mainly in the hosts pen/ nest
47
What are the two main ways you can treat for mites and ticks?
* Regular examination of the animals and removal if found
* Acaricides (Moxidectin, Fipronil, Amitraz)
48
What are the clinical signs of demodecosis
| caused by demodex
* There is often no signs at all as demodex is a commensal
* Can lead to generalised demodicosis
* Can be itchy if the mite numbers are high
* Sometimes its just a localised area of alopecia
* You should always check for underlying disease
