Arthropods - Details Flashcards
(36 cards)
1
Q
Bot Flies
Also known as?
A
Larval Dipterans
Bot = Larvae = Maggot
2
Q
Bot Flies
General Characteristics
A
- Larvae develop in animal host.
- Larvae are called bots.
- Larvae can infect wide variety of domestic animals.
- each one very host & site specific.
- Causes a disease called myiasis.
3
Q
Bot Flies
Facultative Myiasis
A
Facultative Myiasis
- Fly larvae are usually free living but can become subcutaneous.
- Include Musca domestica, the blow flies, & flesh flies.
- Usually due to an open wound on host animal.
- Adult fly will lay eggs on blood on open wound.
- Larvae hatch & feed on dead cells, secretions, & debris.
- not on living tissue
- this is known as fly strike or strike.
- Maggots can create tissue cavities up to several cm in skin.
- filled with maggots.
- Infested animal can die from shock, infection, intoxication.
- Lesions give off a peculiar & distinct smell.
4
Q
Bot Flies
Obligatory Myiasis
A
Obligatory Myiasis
- Fly larvae would NOT survive w/out parasitizing host.
- Include the other skin bots, stomach bots, and nasal bots.
5
Q
Cuterebra spp. What animal(s) does it infect?
A
Rabbit, Squirrel, Mice, Rat, Chipmunk, sometimes Dog & Cat.
*rodents are usual host.
6
Q
Cuterebra spp.
Life Cycle
A
- Adult lays eggs near entrance to rodent burrows.
- 1st stage larva hatches & can enter body orifices or wounds of another animal.
- Pets contract while inspecting rodent burrow
- most common sites in pets: neck & head. - Larvae mature in subcutaneous lesion in ~1 mo
- Larvae leave host & pupate on ground.
- Adults emerge from pupae.
- Adults are rarely seen.
- do NOT have mouth parts, do NOT feed.
- only live long enough to reproduce.
7
Q
Cuterebra spp.
Symptoms & Disease
A
Creates a characteristic lesion on host.
- swollen, round, cyst-like.
- has a fistula, or central pore.
- acts as air hole for larva inside.
- Can also form lesions in cranium, anterior eye chamber, & throat.
- Vet must enlarge hole & carefully extract.
- crushing larva: animal may day from anaphylaxis.
- larva full of toxins.
- 2nd and 3rd stage larva usually in lesion.
- Extracted larva can be up to 3-4cm long.
8
Q
Cuterebra spp.
Diagnosis
A
3rd stage larvae covered w/ black spines.
9
Q
Hypoderma spp. What animal(s) does it infect?
A
Cattle
10
Q
Hypoderma spp., Gasterophilus spp., Oestrus ovis
General Characteristics
A
Adults are heavy & resemble honeybees.
11
Q
Hypoderma spp.
Life Cycle
A
- Adult lays eggs (1mm) on hair shaft of cow.
- Eggs hatch and larvae penetrate skin.
- Larvae wander through skin, esophagus, or spinal column region until they reach the subcutaneous tissues of the back.
- In the back, larvae create breathing holes & characteristic lesions.
- Eventually fall to ground & pupate.
12
Q
Hypoderma spp.
Symptoms & Disease
A
As with Cuterebra spp:
- the larvae must be carefully extracted.
- full of toxins.
13
Q
Gasterophilus spp. What animal(s) does it infect?
A
Horses
14
Q
Gasterophilus spp.
Life Cycle
A
- Late summer / early fall adults lay eggs on hairs of horse.
- egg laying is very annoying to horse.
- can even cause horse to panic. - Horses lick eggs off hair.
- 1st stage larvae penetrate mucosa of mouth & lips.
- Penetrate the mucosa & migrate to stomach.
- Larvae remain attached to stomach lining for 10-12 months.
- up to 2 cm long.
- have hooks & spines. - Larvae pass out of host feces in spring.
- Pupate on the ground for a few weeks.
- Adult emerges from pupa.
15
Q
Gasterophilus spp.
Diagnosis
A
- Seeing adult flies around horses.
- Seeing eggs on hair.
- seeing larvae in feces.
16
Q
Oestrus ovis What animal(s) does it infect?
A
Sheep
17
Q
Oestrus ovis
Life Cycle
A
- Adult lays eggs in nostrils of sheep.
- Larvae develop in nasal cavity & sinuses.
- are white, yellow, or brown, usually dark brown.
- can be up to 3 cm long.
- Larvae fall out of nostrils and pupate on the ground.
18
Q
Oestrus ovis
Symptoms & Disease
A
Produce a respiratory myiasis in sheep.
- Head-shaking.
- Snorting and sneezing.
- excess nasal mucus.
- respiratory distress.
19
Q
Order Anoplura
Also known as?
A
Sucking Lice
20
Q
Order Anoplura
General Characteristics
A
- Larger of the 2.
- Head narrower than thorax.
- Mouth parts for piercing & sucking.
- Do NOT parasitize birds or cats.
- most other domestic animals/humans.
21
Q
Order Mallophaga
Also known as?
A
Chewing or Biting Lice
22
Q
Order Mallophaga
General Characteristics
A
- Smaller of the 2, essentially microscopic.
- Usually yellow.
- Have a large rounded head.
- wider than thorax.
- Mouth parts for biting/chewing.
- All bird lice are Mallophaga.
- birds often pick off and ingest them.
- Feed off epidermal tissues & materials.
- ex: keratin
- not harmful, just annoying.
23
Q
Lice (Anoplura & Mallophaga)
General Characteristics
A
Some of the most prolific ectoparasites of domesticated & wild animals.
- Flat, wingless, insects.
- Three body parts:
- Head – with mouthparts.
- Thorax – with 3 pairs of legs.
- Abdomen – contains repro & digestive organs.
- Spend their entire lives among the hair/feathers of host.
24
Q
Lice (Anoplura & Mallophaga)
Life Cycle
A
Entire life cycle takes 3-4 weeks.
Eggs
- called nits.
- are securely attached to hair/feathers of host.
- oval, white
- tiny (0.5 to 1 mm)
- have operculums that pop open to hatch the nymph.
Nymphs (juveniles)
- hatch from eggs ~5 to 14 days after being laid.
- look very similar to adult.
- smaller, no repro organs.
- molt 3x before growing to adult.
Adults
-nymph becomes adult in 2-3 weeks.
25
Lice (Anoplura & Mallophaga)
| Symptoms & Disease
Disease/Symptoms
- called pediculosis
* infected w/Lice.
- usually more of a nuisance than threat to host.
- do not serve as vectors or ih's.
* except human louse.
- takes many lice to drain host of vitality.
- heavily infested animals may show signs of illness:
1. sucking lice can cause severe anemia in host.
* fatalities can occur in young animals
2. up to a million lice can be on a single animal.
3. more susceptible to other diseases/parasites.
Transmission
- usually by direct contact.
- long fomite life for all stages.
26
Lice (Anoplura & Mallophaga)
| Diagnosis
- finding nits on hair/feather or lice on host.
- use morphology of adult to id.
- also use host specificity to id.
* each type is VERY host specific.
- usually can only distinguish it as a sucking or biting louse.
* that +knowledge of host is enough to id.
27
```
Linognathus spp.
What animal(s) does it infect?
```
Cattle, sheep, goats, dogs, foxes.
28
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Polyplax spp.
What animal(s) does it infect?
```
Rats, mice.
29
```
Pthirus
What animal(s) does it infect?
```
Humans, Dogs (not normal host)
30
Pthirus
| General Characteristics
In humans:
- on pubic hair, armpits, perianal, mustache, beard, eyebrows, eyelashes.
- extreme itching & dermatitis.
- entire family may be parasitized at once.
* spread by fomites.
* sometimes family dog is euth because he is thought to be reservoir. NOT TRUE!!
31
```
Pediculus spp.
What animal(s) does it infect?
```
Humans, rarely dogs.
32
```
Trichodectes canis
What animal(s) does it infect?
```
Dogs
33
Trichodectes canis
| General Characteristics
- may be IH for Dipylidium caninum.
- a wintertime problem.
- skin irritation, pruritis, licking, biting, alopecia.
34
```
Felicola subrostratus
What animal(s) does it infect?
```
Cats
35
Felicola subrostratus
| General Characteristics
-symptoms same as for Trichodectes spp. on dogs.
36
Cuterebra spp.
| General Characteristics
- Larvae are subcutaneous or may be ingested.
| - Dogs & Cats are abnormal host.
