SA/EQ Ectoparasites Flashcards
1
Q
Nuisance flies are of the which family of Diptera?
A
Muscidae
2
Q
What are the feeding habits of the Muscidae family?
A
They feed on bodily secretions or suck blood
3
Q
How does the morphology of T.tabanus and T.haematopota differ?
A
Tabanus has clear wings whereas haematopota has mottled colored wings
4
Q
Tabanidae species can be vectors of which major diseases/ parasites?
A
- Equine infectious anaemia
- Bacillus anthracis
- Trypanosomes evansi
5
Q
This pool feeding fly breeds in wet pasture or marsh lands and causes gadding in cattle through July and August.
A
tabanidae tabanus
6
Q
Which species of Muscidae causes sweet itch in horses?
A
Culicoides spp.
7
Q
Sweet itch is also known as ?
A
Seasonal recurrent dermatitis
8
Q
How long does it take for culicoides to develop from egg to adult?
A
About three weeks
9
Q
Culicoides species can act as a vet to for which major diseases?
A
- African horse sickness
- Blue tongue
- Schmallenberg
- Protozoa/ nematodes
10
Q
Simulium flies are also known by which name?
A
Black fly
11
Q
Name the two main species of culicoides flies.
A
- Imisola
- Obsoletus
12
Q
Non- biting Muscidae feed upon what from its host?
A
Bodily secretions:
Saliva
Tears
Milk
13
Q
This non-biting Muscidae fly can be identified by its orange wing base and olive abdomen. It causes August bag in dairy cattle.
A
Hydrotaea irittans
14
Q
How many life cycles will a culicoides go through a year?
A
1
15
Q
Gasterophilus species are more commonly known as what?
A
Bot flies
16
Q
Name the three main species of gastrophilus flies.
A
- Intestinalis
- Nasalis
- Haemorrhoidalis
17
Q
Male culicoides feed upon what?
A
Nectar
18
Q
This non-biting Muscidae is characterised by a wing vein tick. It is also known as the face fly.
A
Musca autumnalis
19
Q
What is the ideal environment for stomoxys calcitrans to breed?
A
- Dung
- Old feed
- Decaying matter
20
Q
What is gadding?
A
Restless/ agitated behavior in response to fly bites
21
Q
Why are the bites of stomoxys calcitrans very painful for the horse?
A
Their have a long pointed proboscis
22
Q
How can stable fly attacks be minimalised in the horse?
A
Regular application of pyrethrins, eliminating breeding sites (dung, old bedding), repellents, barriers to flies.
23
Q
What clinical condition are black fly seen to cause?
A
Aural plaques
24
Q
- This type of ectoparasiticide targets the AchE enzyme of the parasite.
- What effect does this have?
A
- Organophosphates
- Causes accumulation of neurotransmitter therefore leading to paralysis. Can be toxic to other species.
25
Synthetic pyrethroids have natural analogues which originate from which plant?
Chrysanthemum
26
1. Outline the mode of action of synthetic pyrethroids.
2. Which parasite are they used to target?
1. Cause depolarisation of cell membranes via voltage-gated Na+ channelsand therefore paralysis.
2. Lice and ticks.
27
1. Moxidectin is an example of which class of parasiticides.
2. What are they used against?
1. Macrocyclic lactones - milbemycins They are endectocides - effective against lots of
2. Arthropoda and nematodes.
28
This ectoparasiticide stimulates the release of GABA NT leading to hyperpolarisation of the NS of the parasite. It is highly lipophilic and therefore persists within the body.
Macrocyclic lactones
29
Which insect growth regulator acts to inhibit normal chitin synthesis?
Insect development inhibitors
30
Name an insect development inhibitor which is used in the control of blow flies for up to 14 weeks.
Triazine derivatives, cyromazine
31
Name a juvenile hormone analogue.
Methoprene
32
This flea adulticide targets nicotinic ACh receptors of the parasite.
Imidacloprid - a neonicotinoid
33
Explain why fipronil has a long residual activity.
It diffuses into hair follicle associated sebaceous glands therefore acting as a reservoir .
34
1. This ectoparasiticide is used against sarcoptes and demodex and acts at octopamine receptor sites.
2. What does their action cause?
1. Amitraz
2. Causes neuronal hyperexcitability and death
35
Describe the external features of Arthropoda.
* An external waterproofed skeleton made from alpha chitin.
* A segmented body.
* Jointed limbs.
36
Myiasis
Laying of eggs by flies which hatch and burrow into the host.
37
Which type of ectoparasite lifecycle is more difficult to hold?
Permanent or temporary?
Temporary
38
Ectoparasite circulatory system.
Haemocoele
39
Spiricles
Holes in the side of the insect used in respiration.
40
Mechanical digestion of food in insects occurs in which organs?
Foregut, crop, proventricles
41
What is the function of the makpighian tubules of an insect?
Filters waste from haemolymph into the gut.
42
What is the difference between holometabolous and heminetabolous
* Holo = complete metamorphosis
* Hemi = incomplete metamorphosis
43
What is the structural difference between a tick nymph and adult?
Nymph has only six legs whereas the adult has eight.
44
Name the different parts and function of the haemtopota mouthpart.
* Palp Labrum - upper lip
* Mandible - cutting/ slashing
* Hypopharynx - tongue like
* Maxillae Labium/ labellum - Lower lip
45
Describe the specialised mouthpart of H. irritans.
Sponging
For secretions, not blood
46
What is the function of the hypostome of the tick?
Secretes cementing factors and anticoagulant.
Has serrated spines to anchor them to the skins.
47
Name the three feeding habits of different types of mite and give an example for each.
1. Skin burrowing - sarcoptes
2. Follicle - dwelling - demodex
3. Surface feeding - psoroptes ovis (sheep scab)/ Cheyletiella
4. Obligate blood suckers - poultry red mite
48
A pool feeding fly which breeds in wet pasture, marshy lands and edges of ponds and ditches.
Tabanids
49
Causes gadding in horses during July/ early August.
Tabanids
50
Pruritis caused by culicoides is caused by what?
Hypersensitivity to culicoides saliva.
51
African horse sickness is an example of which type of virus?
Orbivirus
52
This species of culicoides is the vector of bluetongue in Northern Europe.
C. imicola
53
This species of fly lay their eggs in rivers which hatch into aquatic larvae that depend on flowing water.
Simulium spp.
54
Simulium are vectors of which diseases?
River blindness - Onchocerca
Leucocytozoon - Geese and ducks
55
Describe the behaviour of S. calcitrans.
Rest/ mate on sun exposed walls
Feed on lower parts of the animal
56
S. calcitrans acts as a vector for which diseases?
1. Equibe infectious anaemia
2. Anthrax
3. Habronema
4. Bovine viral diarrhoea
57
Name the three main non-biting muscidae.
* H. Irritans - headfly
* M. Autumnalis - facefly
* M. Domestica- housefly
58
This species of fly does not enter buildings and is mainly found in overcast, warm and humid August days.
H. irritans
59
Name the species of gastrophillus and describe where each lays their eggs on the horse.
* Intestinalis - inner forelegs and hocks
* Nasalis- laid under the jaw
* Haemorrhoidalis- lips
60
Outline the basic lifecycle of G. intestinalis.
Eggs ingested, burrow into tongue, moult and exit to pharynx, moult to L2, migrate to oesophageal stomach, moult to L3 remain until spring, passed in the dung and mature to adults.
61
How can gastrophillus infections be controlled?
Ivermectin or moxidectin infections
Removal of eggs
62
Pediculosis is caused by which mite?
* The disease is characterised by which clinical symptoms.
Trichodectes canis
* Mites on head, neck and tail 1cm eggs can be seen on hairs
* Alopecia
* Excoriation
* Inflammation
63
Describe the morphology of Trichodectes canis
* Small (1-2mm)
* Yellow dark marks on abdomen
* Claws to grip hairs
64
How long can Trichodectes canis survive off the host?
7 days
65
Mites have what type of lifecycle complete or incomplete?
Incomplete lifecycle, they go through 3 nymph stages.
66
Name this rare sucking louse of cats and dogs.
Linognathus stetosus
67
Describe morphology and distribution of Felicola subrostrata.
Triangular shaped head
Cause lesions on the face, pinnae and back.
68
1. This ectoparasiticide disrupts the CNS of the parasite by blocking GABA and other ligand-gated chloride channels.
2. How long does it persist in the body?
3. How long does it take to kill fleas and lice?
1. Fipronil
2. 60 days but weakens
3. 24 hrs to kill fleas and 48hrs to kill lice
69
Imidacloprid blocks which type of neurotransmitter channel?
Nicotinic acetylcholine receptors
70
1. Fluralaner is an example of which type of ectoparasiticide?
2. What is this classes mode of action?
3. How do they distribute in the body?
1. Isoxazoline
2. Inhibitors of CNS, blocks GABA and glutamate channels, they target newly emerging fleas
3. Systemic, particularly in fat.
71
Describe the lifecycle of the flea.
1. Eggs - laid on host and fall off into environment
2. Larvae - 3 larval stages - they are positively geotactic (move in response to gravity)
3. Pupae - pre emerging adults - can wait up to 6 months
4. Adult fleas - live permanently on the host - lay eggs 48hrs after infestation
72
Cat scratch disease is caused by which pathogen spread by cat fleas.
Bartonella
73
How do fleas become a vector for Dipylidium canium?
D. canium disintegrates to produce eggs, flea ingests egg pockets, tapeworm develops.
74
How can a flea investation be diagnosed?
1. Flea dirt dehydration2. Signs of flea allergic dermatitis - alopecia, excessive grooming, skin damage 3. Visible signs
75
What taxonomic group do fleas belong to?
Insecta \> Siphonaptera \> Ctenocephalides (canis/ felis)
76
Describe the morphological features of a flea.
Dark brown Wingless
Laterally compressed
Head combs (pronotal and genal)
77
What environmental parameters are required for flea development?
\>70% relative humidity
78
How does the morphology of the two equine lice Mallophaga and Anoplura differ
Mallophaga wide head to body whereas anoplura has a narrow head compared with body
79
Describe the lifecycle of the louse.
1. Eggs - hatch after one to two weeks2. Larva - 3 instar stages3. Adult - lay 200-300 eggs per month on hair/ feathers
80
1. Name two lice found on horses2. Where are they usually found on the body?
1. Haematopinus asini (sucking), Bovicola equi (biting and chewing)2. Dense hair at the tail and mane base
81
1. Cypermethrin shows what type of isomerism?2. How often does its treatment need topping up?
1. Optical - it is 50:50 cis/trans mixture2. 2-4 weeks
82
This ectoparasiticide works as a neuropoison of axons of CNS and PNS using Na channels.Which species should you be wary of when using it?
PermethrinFish
83
Differenciate between the morphology of psoroptic and chorioptes.
Psoroptic have trumpet suckers whereas chorioptes have cup shaped suckers.
84
Which type of lice causes sheep scab and severe disease in sheep and cattle?
Psoroptic spp.
85
How may Chorioptes bovis/equi be treated?
Selenium sulphide or fipronil
86
How long can chorioptes survive off the host?
Up to 3 weeks
87
Which gender of Tabanidae is pool feeding?
Female
88
Dog and cat fleas belong to which taxomic group?
Ctenocephalides
89
Name the main types of pharmacological agents used as ectoparasiticides.
## Footnote
**MASON PII**
* *M**acrocyclic Lactones
* *Am**idines
* *S**ynthetic pyrethroids
* *O**rganophosphates
* *N**eonicotinoids
* *P**henylprazoles
* *I**soxazolines
* *I**nsect growth regulators (JGA and CSI)
