Exam 2--Blagburn Flashcards
__% of parasites live in __% of horses
80, 20
“Hairworm”
Trichostrongylus axei
Found in stomach and SI of variety of species
Trichostrongylus axei
Life Cycle of Trichostrongylus axei
Direct; L3 infective; short pre-patent period
Larva exhibit positive phototropism
Trichostrongylus axei
Pre-Patent period for T. axei
3 weeks (Short)
Causes hyperplastic gastritis and hypoproteinemia
Trichostrongylus axei
“Stomach worms” “spirurids”
Habronema & Draschia spp.
Life Cycle o Habronema & Draschia spp.
Indirect–Muscid Fly; L3 infective; pass larva in feces
Pre-patent period for Habronema & Draschia spp.
2 months
Larval migration choices for Habronema & Draschia spp.
Deposited in wound–lungs, skin, eyes
Ingested–stomach
Causes “Summer Sores”
Habronema & Draschia spp.
“Roundworm”
Parascaris equorum
Inhabit SI of horses (usually foals)
Parascaris equorum
Life Cycle of Parascaris equorum
Direct; L3 infective
Larva undergo hepatotracheal migration
Parascaris equorum
Does P. equorum larva undergo transplaental infection?
No
Pre-patent period of P. equorum
70-90 days
Causes summer colds and colic
Parascaris equorum
Inhabit SI of horses (foals), donkeys, and pigs
Strongyloides westeri
Infections involve ONLY females
Strongyloides westeri
Two types of life cycles for S. westeri
Homogonic–parasitic
Heterogonic–free living
Homogonic life cycle of S. westeri
L3 penetrate skin or are ingested via suckling; migrate to lung, trachea, and intestine
Heterogonic life cycle of S. westeri
Embryonated eggs pass, larva develop to free living adults and produce L3 larva that can enter homogonic LC
T/F S. westeri causes “foal heat diarrhea”
False–probably due to diet changes
“Large equine pinworm”
Oxyuris equi
Inhabits large intestine of horses
Oxyuris equi
Life cycle of Oxyuris equi
Direct; eggs in peranal regin
T/F: Oxyuris equi can exhibit autoinfection/retroinfection
False
Pre-patent period of O. equi
5 months
Causes “pruritis ani”/ “seat itch”
Oxyuris equi
T/F: Equine stronglyes are named large and small based on size ONLY
False
How many species of strongyles make up the majority of worm burden
~5
Small strongyle life cycle
Direct; encyst in muscosa until weather is favorable
Large strongyle life cycle
Direct; migrate to cranial mesenteric a and are carried back to intestine
Which of the follow are migratory: Large or small strongyles?
Large strongyles
Which has a longer pre-patent period? Large or small stronglyes?
Large
Cause Larval cyathostomiasis
small strongyles
Cause verminosus arteritis
Large strongyles (S. vulgaris)
Associated with thromboembolic colic
Large Stronglyes (S. vulgaris)
“Equine lungworm”
Dictyocaulus arnfieldi
Inhabit bronchi and brochioles of equids
Dictyocaulus arnfieldi
Life cycle of Dictyocaulus arnfieldi
Embryonated egg; Direct; migrate to lungs via lymphatics
T/F: Dictyocaulus arnfieldi is a TRUE lungworm
False—Direct life cycle
Causes verminous pneumonia
Dictyocaulus arnfieldi
“Equine eyeworm”
Thelazia lacrymalis
Inhabits conjunctival sac and lachrymal ducts of horses (especially
Thelazia lacrymalis
Life cycle of Thelazia lacrymalis
embryonated egg; Indirect–Face flies
“Neck threadworm”
Onchocerca cervicalis
Inhabits nuchal ligament of horses
Onchocerca cervicalis
Life cycle of Onchocerca cervicalis
Indirect–Midges
T/F: Onchocerca cervicalis is considered to be a filariid
True
Causes “Equine recurrent uvetitis” (Moon blindness)
Onchocerca cervicalis
T/F: Onchocerca cervicalis is responsible for “Fistulous withers”
False
Can cause CNS disease similar to viral encephalitis
Micronema deletrix
Where and who do HOTC complex neamtodes inhabit?
Abomasum and SI; mostly herbivores
HOTC stands for?
Haemoncus, Osteragia, Trichostrongylus, Cooperia
“Barberpole worm”
Haemonchus spp.
“Brown stomach worm” “Bankrupt worm”
Osteragia spp.
“Hairworm”
Trichostrongylus spp.
“Cooper’s worm”
Cooperia spp.
Cause anemina and bottle jaw (two)
Haemonchus and Ostertagia
Caues “morocco leather” appearance of abomasum
Ostertagia
Which of the HOTC complex is most commmon?
Cooperia
Larval inhibition associated with which HOTC species?
Ostertagia
Spontaneous expulsion of adult parasites from abomasum (lambs)
Self-cure.. assoc. w/ H. contortus
When egg counts rise significantly in spring/early summer
Spring Rise
“Intestinal threadworm”
Strongyloides papillosus
Can exhibit transplacental and transcolostral tramission
Strongyloides papillosus
“Ruminant ascarid”
Toxocara (Neoascaris) vitulorum
Inhabits SI of cattle and ruminants
Toxocara (Neoascaris) vitulorum
Life cycle of Toxocara (Neoascaris) vitulorum
Direct; L3 ingested and distributed to tissues
Which form of transmission for T. vitulorum leads to egg-laying infections?
newborn and suckling calves
“Whipworms”
Trichuris spp. (ovis and discolor)
Where do Trichuris spp. inhabit?
cecum and upper colon
“Nodular worms”
Oesophagostomum spp.
Inhabit large intestine of variety of species (cattle, sheep, goats)
Oesophagostomum spp.
Can form nodules on intestinal wall and lead to malabsorption, diarrhea, and weight loss
Oesophagostomum spp.
“lungworm”
Dicyocaulus viviparous
Inhabits trachea, bronchi, and bronchioles of ruminants
Dicyocaulus viviparous
Life cycle of Dicyocaulus viviparous
Direct; L3 ingested larva migrate lymphatics–>heart–>lungs; pass embryonated eggs
T/F: Dicyocaulus viviparous is a true lungworm
False
Causes “husk” and emphysema
Dicyocaulus viviparous
“Hair lungworm”
Muellerius capillaris
Inhabits lungs parenchyma of sheep, goats, and wild ruminants
Muellerius capillaris
Contains posterior dorsal appendage
Muellerius capillaris
Life cycle of Muellerius capillaris
Indirect–snails and slugs; pass larva in feces
T/F: Muellerius capillaris is a true lungworm
True
Causes villous endarteritis
Dirofilaria immitis
Intermediate host for Dipetalonema (Acanthocheilonema) reconditum
Fleas
Which parasites are ascarids/roundworms
P. equorum, T. vitulorum, A. suum