Equine Parasites: Playtyhelminthes and Arthropods Flashcards
What are the equine cestode parasites we are studying?
Anoplocephala perfoliata
Anoplocephala magna
What are some general facts that all cestodes have in common?
1 intermediate host
Attach with scolex and suckers
Egg is called oncosphere
Dipylidium caninum is the model
Which is more common? A. perfoliata or A. magna?
A. perfoliata
Which cestode is larger? A. perfoliata or A. magna?
A. magna (80 cm vs. 4 cm)
Which cestode has “lappets” ?
A. perfoliata
Perfoliata= laPPets
What do the eggs of A. perfoliata and A. magna look like?
50-80 Mm
Irregular shape
Contains small hexicanth embryo
Describe the life cycle of A. perfoliata and A. magna.
Mature segments pass in feces
Eggs are released
Eggs ingested by mites
Eggs develop into cysticercoid inside the mite
Infected mite with cysticercoid ingested by the horse while grazing
What is the PPP of A. perfoliata and A. magna?
1-2 months
What is the intermediate host of A. perfoliata and A. magna?
forage mite or oribatid
Is seasonality associated with A. perfoliata and A. magna?
No
Where is the site of infection for A. perfoliata?
Cecum. More specifically, the ileocecal valve
Where does A. magna infect?
Small intestine
Heavy infections of A. _______ cause ulcerations.
A. perfoliata
What can a heavy infection of A. perfoliata do to the ileocecal valve? To the terminal ileum or cecum?
Cause partial occlusion or intussusception of the terminal ileum or cecum
How do you diagnose A. perfoliata and A. magna?
Use centrifugation and fecal flotation
Use sedimentation
Use ELISA
How are A. perfoliata and A. magna treated?
Praziquantel
Is A. perfoliata or A. magna more pathogenic?
A. perfoliata is more pathogenic
Which equine parasitic flies are we studying?
Gasterophilus spp. Musca autumnalis Stomoxys calcitrans Culicoides spp. Tabanus spp. Chrysops spp.
What is the common name for Gasterophilus spp. ?
Bot fly larvae
Describe the life cycle of Gasterophilus spp.
Egg
Larva
Puparium
Adult
Where are you most likely to find the eggs of Gasterophilus intestinalis?
On the forelegs and shoulders
Where are you most likely to find the 3rd instars of Gasterophilus intestinalis?
Non-glandular stomach and cardiac region of stomach
Where will you find the eggs of Gasterophilus nasalis?
Intermandibular spaces
Where will you find the 3rd instars of Gasterophilus nasalis?
Pylorus and duodenum
Which egg will hatch into a 1st instar when licked (of the two Gasterophilus species)?
Gasterophilus intestinalis
Where does the 1st instar develop into the 2nd instar?
In the oral cavity
When does the 2nd instar change into the 3rd instar?
When swallowed
How long can a 3rd instar live inside the horse?
12 months
What color is Gasterophilus intestinalis in fresh feces?
Red
What color is Gasterophilus nasalis in fresh feces?
Yellow
Where does infestation of Gasterophilus intestinalis 3rd instar occur?
Stomach