Introduction to Parasites Flashcards
1
Q
what is a parasite?
A
lives at the expense of another organism (host) in a long term association without causing immediate death of the host
2
Q
what is an obligatory host-parasite relationship?
A
whole life cycle of parasite takes place on/in the host
3
Q
what is a faculative host-parasite relationship?
A
parasite only spends part of it’s life cycle on the host
4
Q
what happens during continuous feeding?
A
parasite constantly feeds from host
5
Q
what happens during intermittent feeding?
A
the parasite feeds on and off from the host
6
Q
how can parasites affect the host?
A
blood loss (anemia) due to feeding tissue damage inflammation and pruritus allergic responses
7
Q
what is pruritus?
A
self-harm (biting/scratching)
8
Q
what can parasite infestation lead to?
A
reduced weight gain skin wounds-microbial infection
9
Q
what are the characteristics of insects?
A
segmented jointed legs exoskeleton joints at junctions body cavity heart spiricles
10
Q
what is the function of an insects exoskeleton?
A
protects the insect from trauma and loss of body fluid
11
Q
what is scleretization?
A
chemical changes that make the sclera hard so it forms the exoskeleton
12
Q
what is the body cavity of insects known as?
A
haemocoel
13
Q
what does the dorsal vessel of insects contain?
A
blood and nervous tissue
14
Q
what is the tergum of an insect?
A
most dorsal part of the insects body
15
Q
what are spiracles?
A
holes in an insects body through which respiration takes place
16
Q
what is the name of the breathing apparatus of acari?
A
stigmata
17
Q
what is gnathosoma?
A
mouth parts of insects
18
Q
what are podosoma?
A
attachment points for the legs
19
Q
what is the idiosoma made up of?
A
podosoma and opisthosoma
20
Q
what can be used to identify mites?
A
claws and pulvillus (pads seen between claws)
21
Q
describe the life cycle of mites
A
egg - 6 legged lavae - nymph - deutonymph - tritonymph - adult
22
Q
where do scabies causing mites live on the host?
A
adult females burrow into the upper layers of the skin
23
Q
how many days from egg to adult in sarcoptic mites?
A
17-21
24
Q
how long do sarcoptic mites survive off host?
A
2-3 weeks
25
what are the symptoms of sacbies?
intense itching, inflammation, hair loss, crusts of dried exudate
26
what behaviors can scabies cause?
extreme self harm and hypersensitivity and death of host in 2-4 months
27
what animals is scabies common in?
dogs and pigs but also seen in humans and camalids
28
where is the site of scabies infection in dogs?
pinnae and ventrum (abdomen)
29
where is the site of scabies infection in pigs?
external ear canals and dorsum (back)
30
can scabies infestation be asymptomatic?
yes
31
what do sarcoptiform mites cause in guinea pigs?
scabies
32
what are otodectes cynotis also known as?
ear mites
33
what are the hosts of ear mites?
cats, dogs and other carnivores
34
how many eggs do adult ear mites produce?
15-20
35
how long do adult ear mites live for?
2-3 weeks
36
how do ear mites differ from scabies bacteria?
smaller and do not have jointed pretarsi
37
where are ear mites found?
deep in the horizontal ear canal
38
how common are ear mites?
not as common as poeple think, usually seen in welfare cases
39
how long are demodicosis mites?
0.1-0.4 mm
40
where are demodicosis mites found on animals?
sebaceous glands and hair folicles
41
how long is the life cycle of demodicosis mites?
18-24 days
42
how are demodicosis mites passed on?
suckling puppies from their mother
43
what animal are demodicosis mites common in?
dogs
44
how long can cheyletiella survive for off the host?
10 days
45
how long are cheyletiella?
0.4mm
46
what do cheyletiella cause?
dermatitis
47
how contagious are cheyletiella?
very contagious
48
are cheyletiella zoonotic?
yes
49
what animals do cheyletiella affect?
dogs, cats and rabbits
50
what are trombiculidae?
six legged larvae of adult mite
51
what do trombiculidae cause?
pruritic skin disease
52
where are trombiculidae present in the environment?
vegetation in mid to late summer an autumn particularly where fruit is grown
53
when do trombiculidae larvae attach and how long for?
for 3 days and drop off to complete their life cycle in the environment
54
what can occur in the host due to trombiculidae mite?
hypersensitivity to mite and products which can lead to pruritus
55
what can ticks carry?
disease
56
what is the hypostome of a tick?
part of the gnathosoma which has back facing teeth to aid attachment of tick to body
57
what does the saliva of ticks contain?
vaso-active prostaglandins
anti-coagulants
cytolytic agents
chemotactic agents
salivary glyco-proteins
58
what do salivary glyco-proteins do in the tick?
help form cement with the hypostome
59
describe the life cycle of the tick
egg - larva -primary host- nymph -secondary host - adult male and female - final host
60
what does the hallers organ on ticks do?
picks up chemical stimuli so that the tick knows when a host is near so they can attach
61
what is questing behavior in a tick?
looking for a host
62
what is the life cycle of the ixodes ricinus (deer tick)?
eggs hatch larvae feed from host 1 fully fed larva drop to the ground larva molts to nymph nymphs feed on host 2 fully fed nymph drops to the ground nymph molts to adult adults feed on host 3 fully fed adult drops to the ground oviposition
63
how many hosts are involved in the life cycle of ixodes ricinus (deer tick)?
3
64
what animals are usually hosts 1, 2 and 3 for ixodes ricinus (deer tick)?
1. rats/mice 2. rabbits 3. sheep/deer
65
what disease do ticks carry?
lymes disease
66
does lymes disease affect animals?
not really
67
what is the insect life cycle known as?
holometabolous life cycle
68
describe the life cycle of a flea
egg - larva - pupa - adult
69
where is the flea egg laid?
on the host (cat/dog) or in the area close to the host
70
when does the female flea begin to lay eggs?
usually 48 hours after the female flea has mated and started feeding
71
how many eggs may a flea lay over several weeks?
2000
72
after how many days does the flea egg hatch into a larva?
1-10
73
where does the flea larva move to and why?
deep into carpets and under furniture due to susceptibility to light
74
how far can fleas crawl through through a carpet while feeding?
up to 50cm
75
what do larval fleas feed on?
organic debris including flea faeces ad tapeworm segaments
76
after how many days does the flea larva form pupa?
5-11 days
77
where do flea pupa live?
deep in carpet pile and bedding areas protected from chemicals
78
how long can adult fleas remain in the cocoon stage for?
weeks or months depending on the environmental conditions
79
what are the stimuli for emergence of adult fleas from pupa stage?
increase in temperature and mechanical pressure
80
when do adult fleas usually emerge from pupae cocoon?
5-10 days
81
what do fleas rely on to locate host?
heat and visual cues
82
once the flea has fed how long can it survive away from the host?
3 days
83
how long does a complete flea life cycle take in conditions of most homes?
3-5 weeks
84
how long can unfed fleas survive for?
10-60 days depending on the humidity and temperature of environment
85
what are the signs of flea infestation in animals?
pruitus
alopecia
self-wounding
excoration
hypersensitivity
anemia
86
what are the key visible differences between chewing lice and sucking lice?
chewing: flattened and round head sucking: short pointed head
87
what is the life cycle of lice?
egg - nymph - lice
88
where do lice eggs attach?
to hair/fur
89
what is the only louse that commonly occurs on cats?
felicola subrostratus
90
is felicola subrostratus of pathogenic importance in cats?
only if the cat is elderly or has chronic illness.
91
in what breeds may felicola subrostratus be more problematic?
long haired breeds
92
where on the body is trichodectes canis usually found?
head, neck and tail of dogs
93
what does a trichodectes canis infestation cause?
intense irritation
94
what does damage to the skin resulting from itching due to trichodectes canis infestation cause?
inflammation, excoration, alopecia and secondary bacterial involvement
95
what do trichodectes canis act as intermediate hosts for?
tapeworm
96
where can flies be found on an animal?
dermal sub-dermal cutaneous nasopharyngeal ocular intestinal/entric urinogenital
97
where do gasterophilus spp. lay their eggs on the horse?
legs
98
how do gasterophilus spp. get into the horse stomach?
licked off the legs by horse and make their way into the stomach
99
how do gasterophilus spp. exit the body?
detatch from the stomach and are expelled in faeces
100
when is rabbit strike more likely?
in rabbits with a high starch diet - more prone to diarrhoea than those on a diet with digestible fibre in rabbits where grooming behavior is interrupted (e.g. mouth pain caused by dental abnormalities, infection of area or of bones)
101
what disease does the sand fly cause?
canine leishmaniosis
102
where is canine leishmaniosis often seen?
europe
103
what does hypersensitivity to the culicoides midge cause in horses?
sweet itch
104
what are the signs of sweet itch?
self trauma, particularly at mane and tail
105
what is the life cycle of the culicoides midge?
egg - aquatic larva - pupa - adult
106
what phase of the life cycle of the culicoides midge requires water?
aquatic larva phase
107
how long can adult culicoides midge live?
maximum 20 days
108
are culicoides midge strong fliers?
no, only fly a few hundred metres
109
what are the most important of the equine parasites?
strongyles (large roundworm)
110
where in the body do strongyles (large roundworm) develop to maturity?
large intestine
111
where do strongyles migrate before they mature?
anterior mysenteric arteries, through the liver to the subperitoneal connective tissues and to the liver and the pancreatic renal region
112
what is the cause of long prepatent periods of strongyles (redworm)?
the long larval migrations
113
what can damage caused by migrating strongyles (redworm) cause?
severe pathological consequences (including colic)
114
do small roundworms migrate?
not extensively
115
when do small roundworm larva damage mucosa?
on emergence
116
what is acute larval cyathostomosis (ALC)?
damage caused by mass emergence of larva
117
name 5 key equine parasites
parascaris (roundworm) tapeworm (anoplocephala) bot flies culicoides midge fly worry (e.g. horse flies)
118
what is anthelmetic resistance?
growing resistance by worms to the treatment used to eradicate them
119
how can treatment be altered to stop wormer resistance?
targeted using testing to judge when teratment is needed (e.g. FWEC)
120
at what level of worm burden can horses be wormed?
200 epg (eggs per gram)
121
what worm should be treated for every autumn?
encysted cyathostomins (small redworm)
122
where is toxocara canis found in dogs and cats?
small intestine
123
where does toxocara canis migrate in dogs and cats and how long does migration stage last?
liver and lung tissue
4-6 months
124
what sort of worms are taeniidae?
tapeworm
125
where are adult tapeworms found?
intestine of carnivores
126
where are the immature stages of tapeworms found?
cysts in various organs of herbivores
127
what are the two genera of tapeworms?
taenia and echinococcus
128
what is the strobila of tapeworms?
the body
129
what are protoglottids of tapeworms?
segments which form the body
130
what do progolottids contain?
genitalia and so eggs
131
how do proglottids release eggs?
seperate from main worm and pass out in faeces where they break down and release eggs into the environment
132
in what species are echinococcus granulosus found in?
dogs
133
what are angiostrongylus also known as?
lungworm
134
what are the clinical signs of early lungworm infection?
harsh, dry cough dysponea anemia depression anorexia signs of coagulopathy
135
what are the signs of chronic lungworm infection?
verminious pneumonia leading to anorexia, weight loss, emaciation and pulmonary hypertension
136
how can the presence of lungworm be diagnosed?
faecal examination blood test
137
How does lungworm arise in dogs?
ingestion of intermediate host (slug/snail)
138
how can angiostrongylus be diagnosed?
in faeces (Baermann test) or bronchoalveolar lavage
139
What are the health threats to dogs from travel into other countries?
rabies
tapeworm
tick borne diseases
exotic ticks
leishmaniosis
140
what does toxoplasmosis cause in sheep?
abortion
141
What mites can be seen in this tissue sample of scabies?
Sarcoptes mites
142
What type of parasite is this and what is it's name?
Mite
Cheyletiella
143
what type of parasite is this and what is its name?
Mite
Trombiculidae
144
what is caused by this mite?
Mild but highly contageous (zoonotic) dermatitis
145
what is caused by this mite?
pruritic skin disease
146
What is the name of this louse and where is it found?
Felicola subrostratus - chewing lice found on cats
147
what is the name of this louse and where is it found?
Trichodectes canis - found on dogs
148
what is the name of this fly and where is it found?
Gasterophilus (bot fly)
lays it's eggs on the legs of horses and then is ingested - larvae emerge in the stomach
149
what is the name of this fly and what does it cause?
Lucilia sericata - causes myiasis (infestation of areas of the body by flies and maggots) e.g. rabbit strike
150
what is the name of this fly and what does it cause?
Sand fly - canine leishmaniosis which is a zoonotic disease
151
what is the name of this midge and what does it cause?
Cullicodes
Sweet itch
152
What is the name of these worms and where are they found?
Cythostomins (small roundworms)
intestine of horses - no migration
153
What is the name of these worms and what animal is commonly affected by them?
Echinococcus granulosus (tapeworm family)
found in dogs
154
What is the name of this worm?
Angiostrongylus
155
What is the name of this worm and where is it found?
Echinococcus granulosus (small number of segments)
found in dogs
156
What is the name of this worm?
Diplidium canium
157
What is the name of this worm and how is its presence usually diagnosed?
Pinworm
Not normally found in faeces - would need to use sellotape preparations of the perianal area
158
What is the name of this worm and why may the animal present with colic?
Large Strongoyles (large redworm) - has large mouth with teeth
intestinal blood vessels become blocked due to clots that form around epithelium damaged by worms
159
What is the name of this worm?
Roundworm of chickens
160
