Equine Parasites - Exam 2 Flashcards
1
Q
Draschia megastoma Habronema spp (majus and muscae)
A
- Equine
- A: 13mm, funnel-shaped buccal cavity, nodules margo plicatus; Hab - 22-25mm; E: thinshelled, larvated 40-55um x 8-16um
- Indirect: IH is fly - L3 in skin
- SOI - adults in stomach
- Path - L: cutaneous habronemiasis/draschiasis, ulceration, granular conjuctivitis, nodules in lungs. A: gastritis, nodules/tumors
- Signs: L - summer sores (cutaneous habro) A: gastritis
- Dx - skin scrape for L; E: thin walled and collapse with loss of bouyancy in fecal float
- MCLs and ivermectin
2
Q
Parascaris equorum (ascarid)
A
-Equine
-A: 30cm, 3 large lips; E - thick walled 90um, can survive 23 months
PPP - 2.5m
-Direct: L2 swallowed, hepatic tracheal migration, L3 in trachea is swallowed, L4 to SI 14-17d, A there.
-SI
-Path: perforation, intestinal obstruction, unthriftiness
-Signs: coughing, unthriftiness
-Dx: E in fecal float
-TA: Anthelmentics
3
Q
Stongyloides westeri - threadworm
A
-Equine
-A: slender, 1cm; esophagus 1/3 body length; E: 30-40um
-Direct: homognic - unfavorable conditions - PPP 10-14d;
hetergonic; percutaneous, per os, transpla, transmamm
-A: SI; L:somatic tissue
-Path: erythema from L
-Signs: L: uticaria - wheals. Frenzy - sawdust; A: diarrhea in young
-Dx: fecal float/Baermann L1
-Tx: MCLs
4
Q
Strongylinae vulgaris, edentatis, equinus
A
- large strongyles
- 1.5-5cm, mouth capsuel; E: 60-120 x 35-60um
- PPP - 6-11m
- Direct: L3 per os, L4 migration to cranial mesenteric and ileocolic arteries, 3-4m they migrate in arteries back to LI, eggs in LI - PPP 6m
- L: arteries of intestine; A: LI
- Path: L - arteritis, thrombus, infarction, death, aberrant migration to ccoronary, carotid, ex iliac, spermatic a; A - bloodsuckers and remove plugs in mucosa
- Dx: E: fecal float; L3 culture and id into 2 strongyle groups; Migrating L - ultrasound, rectal exam/palpation, arteriography; A - recovery at necropsy
5
Q
Cyathostominae (small strongyles)
A
- A: <6m
- Tx: Fenbendazole and moxidectin
6
Q
Oxyuris equi
A
- large pinworm
- E: 85x40um, operculum, flatter on 1 side; A: 10cm long white nematode
- Direct in L3
- LI - PPP 4-5m
- Path - pruritis
- Signs - peri-anal irritation
- Dx - broken hair at tailhead from rubbing, scrapings, scotch tape
- Tx - parasiticides
7
Q
Dictyocaulus arnfieldi
A
- Lungworm
- DONKEYs - in Horse, don’t sexually mature
- A: 8cm; L1 - 400um; E: 75um
- Direct - L3 - per os, migrate SI –> lungs via blood/lymph
- Bronchi of lungs - PPP 2-4m
- Path - damage lung tissue, raised circumscribed areas of over inflated pulmonary tissue
- Signs - none is donkey, harsh lung sounds in horse
- Dx - L1 in feces and lung wash - Baerman; Eosinophils in tracheal mucus
- Tx - if endemic, do not pasture horses and donkeys together
8
Q
Anoplocephala perfoliata/magna
-cestode
A
- FH - equids; IH - orbatid mite
- A: perf - 20cm w round scolex, lappet, 4 suckers; mag - 80cm no lappet
- E: perf - anoplocephalid (embryo containing) and 50-80um
- Indirect - egg w oncosphere in feces, mite consumes, cysticercoid (infective) develops and horse eats
- SOI: perf - Cecum/LI; mag - SI
- Path: unthrifiness; perf - ulcerations and diphtheritic memb –> occlusion of ileocecal valve and intussusception of ileum and cecum
- Dx: centrifuge/float, sedimentation, ELISA
- Tx: praziquantel
9
Q
Gasterophilus intestinalis/nasalis
A
- bot fly/larvae/instar
- A: 18mm and robust, irregular dark transverse bands on wings - L3/instar - in feces - red w 2 rows of spines blunted (int) or yellow w 1 row of spines (nas)
- PPP nasalis - 14m
- SOI: E - hair of forelegs or intermandibular area; L3 - nonglandular margo plicatus and cardiac region or duodenal ampulla
- Path: A - annoyance; L3 - inflammation
- Dx: color, spines, and location in host
10
Q
Musca autumnalis
A
- face fly
- equids/cattle
- A: 5.5-7.5mm, light/dark grey, 4 dark longitudinal stripes on thorax, sponging mouthparts, fleshy retractible proboscis; E: 1mm long banana shaped
- LC: E–>maggots (L) –>3 L/instars–> pupa –> adults (feed on face secretions: F lay up to 100 eggs in feces or rotting organic material - length is temp dependent
- SOI - face secretions or wounds
- Path: annoyance, mech transmit viruses, IH for Thelazia lacrymalis (eye nematodes)
- Signs: annoyance interferes w grazing/performance, eye disorders/conjunctivitis
11
Q
Stomoxy calcitrans
A
- Stable fly/biting housefly
- Most animals/humans
- A: 5.5-7.5mm, short abd and 3 dark spots in 2/3rd segments, prominent proboscis, piercing/sucking organ; E: 1mm, banana shaped, white
- LC: A - feed 1-2x/day on blood meals. its 3 minutes/meal; F lays 25-50 eggs in vegetable matter with urine
- SOI: general
- Path: transmit Habronema and trypanosomes
12
Q
Culicoides spp
A
- biting midges (no see ums)
- domestic animals/humans
- A 1.25-5mm, mottled wings over abd, short prothrombus
- LC: eggs in damp marshy ground hatch in 2-9d, 4L stages 14-25d-7m, P at surface and water edge, A emerge 3-10d, F suck blood
- Path: annoyance, trans bluetongue, African horse sickness, Onchocerca (horses/cattle), & protozoa
- Queenland itch and allergic dermatitis
13
Q
Tabanus spp
A
- horse fly/gadfly
- large domestic and wild animals, humans, birds, sm mammals
- large, stout flies, sized from housefly to hummingbird, clear to brownish wings, span 6.5cm, mouthparts adapted for bloodsucking - slashing/sponging
- LC: after blood meal, F lay hundreds eggs in marshy areas, E hatch 1-2w to L, develop in 3m-3y, A fly emerge from P 1-3wk. LC is 4-5m
- Path: anthrax, pasteurellosis, trypanosomosis, anaplasmosis, human filarial dis, loasis
- Signs: annoyance
14
Q
Chrysops spp
A
- deer fly
- ID: same as Tabanus w dark bands on wings
- Everything similar to Tabanus
- Tx/prevent - prefer biting in shade - limit horses to sunny area
15
Q
Chorioptes bovis
A
- Chorioptic mange mite, foot/leg mange, itchy heel
- Equine, cattle, sheep, goats
- ID: M has pretarsi on 4 pairs of legs, F have suckers on short unsegmented stalks on 1, 2, 4. M on 1, 2, 3, 4 (4 is rudimentary)
- LC: Similar to Psoroptes ovis in small rum. F lay about 90 eggs in 4-6 weeks, PPP is 10d
- SOI: distal limb
- Path: crusty lesions w thickened skin on distal limb
- Signs: irritation
- Dx: close exam, skin scrape
