Arthropods - Details Flashcards
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.