Nematodes II: Spirurids and Oxyurids Flashcards
What is the morphology of Spirurida?
Tight spirally coiled tail of male
Most have 2 lateral lips
Esophagus divided into anterior and posterior glandular portion
What are the species in the Spirurida order?
Physaloptera Dracunculus insignis Draschia Habronema Spirocerca lupi
What is the distribution of Physaloptera spp (stomach worm)?
Most common in midwestern US in dogs and cats
Especially in animals with outdoor access/history of prey consumption
What is DH of Physaloptera?
Canids and felids
What is the PPP of Physaloptera?
41-83 days
What is the Physaloptera life cycle?
Larvated eggs in feces DH ingests PH or IH with infective L3 L3 attaches to the stomach wall L4 is in the stomach Adults are in the stomach
What is the IH of Physaloptera?
Beetles, cockroaches, crickets
What is the life cycle of Physaloptera in the IH?
L1 hatches
L2
L3 is infective
What are the PH of Physaloptera?
Amphibians
Reptiles
Mammals
How does the PH get infected with Physaloptera?
Ingest IH first
What is the diagnostic stage of Physaloptera?
Eggs with L1 or adults attached to the mucosa of the stomach
What is the pathogenesis of adult Physaloptera?
Attach to mucosa Feed on blood and mucosa Ulceration Hemorrhage Catarrhal gastritis
What are the Physaloptera clinical signs?
Usually asymptomatic
GI (possibly chronic vomiting, secondary to gastritis, esophagitis, regurgitation)
Systemic (anorexia, weight loss, lethargy)
How can you diagnose Physaloptera adults?
About 44mm
Endoscopy
Vomitus
What is the difference between Ascarid and Physaloptera?
Ascarids are often found in the stomach at necropsy
Physalopteras have the head embedded in mucosa
How do you diagnose Physloptera eggs?
Not usually found on fecal flotation
Fecal sedimentation
What is the distribution of Dracunculus insignis?
North America
What are the DH of Dracunculus insignis?
Raccoons
Mink
Canids
Felids (rare)
What is the Dracunculus insignis life cycle?
L1 released into water
Males die
DH ingests PH or IH with infective L3 (in water)
Females in SubQ extremities
What is the IH of Dracunculus insignis?
Copepods
What is the PH of Dracunculus insignis?
Frogs
Where will you find Dracunuculus insignis L3?
Thoracic and abdominal muscles
SubQ tissues
Where will you find Dracunuculus insignis L4?
SubQ tissues
Where will you find Dracunuculus insignis adult?
SubQ tissues
What are the Dracunculus insignis clinical signs?
Pyogranulomatous inflammation
Chronic nodules or abscesses (primary locations are limbs and abdomen)
How do you diagnose Dracunculus insignis L1?
Impression smears of lesions/discharge
It has a complete digestive tract and it has a prominent, long, and pointed tail
How do you diagnose Dracunculus insignis adult?
Remove adult females from nodules
What is the DH of Draschia and Habronema?
Equids
What are the intermediate hosts of Draschia and Habronema?
Musca domestica (house fly**) Stomoxys calcitrans (stable fly)
What is the distribution of Drachia and Habronema?
Worldwide
In US, the house fly is the most important
What is the life cycle of Draschia and Habronema?
L1 +/- eggs in feces L3 transferred to DH DH ingests IH with infective L3 L3 is in the stomach L4 is in the stomach Adults are in the stomach Eggs hatch in the GI tract
What is the life cycle of Draschia and Habronema in the IH?
L1 ingested by fly larvae
L1 matures to L2 which matures to the infective L3 in the fly
Adult fly feeds on DH
Infective L3 migrates to the head of the fly
Fly feeds on horse
L3 is transferred to DH
Horse licks and ingests infective L3 or ingest fly
Is there a blood meal needed to infect an animals with Draschia and Habronema?
No
What is the Draschia and Habrinema pathogenesis?
Tumor-like lesions near margo plicatus
What are the clinical signs with Draschia and Habronema adults?
Usually asymptomatic
Gastritis
Perforation
Peritonitis
What are the clinical signs with Draschia and Habronema larvae?
Granulomatous lesions
Cutaneous (summer sores)
How do you diagnose Draschia and Habronema eggs?
Not fecal flotation
PCR of feces to differentite species
How do you diagnose Draschia and Habronema larvae?
Lesions
How do you diagnose Draschia and Habronema adults?
Necropsy
What is the DH of Spirocerca lupi (esophageal worm)?
Dogs
Cats
What is the life cycle of Spirocerca lupi?
Larvated eggs in feces
DH ingests PH or IH with infective L3
L3 penetrates gastric wall
L3 walls of gastroepiploic and gastric aa —> celiac artery—> thoracic aorta —> L4 —> adults
Adults migrate to connective tissue
Adults found in nodules in esophageal wall, stomach
What is the IH of Spirocerca lupi?
Coprophagous beetle
How does the IH get Spirocerca lupi?
Ingests L1 in egg
L1 –> L2–> infective L3
What are the PH of Spirocerca lupi?
Mammals
Birds
Lizards
Toads
How does the PH get Spirocerca lupi?
PH ingests IH with infective L3
What is the distribution of Spirocerca lupi?
Worldwide in warmer climates, tropical and subtropical
What is the pathogenesis of Spirocerca lupi?
Aortic aneurysms
Thrombosis
Esophagus has granulomas and sarcomas
Describe nodule/granulomas associated with Spirocerca lupi
Form around worms in wall of esophagus
Describe sarcomas associated with Spirocerca lupi
Worms in wall of esophagus
Sarcoma developed around them
What are the clinical signs associated with Spirocerca lupi?
Esophageal dysphagia Vomiting Esophageal neoplasia Aortic aneurysm or rupture Thickening of long bones chracteristic of hypertrophic osteopathy
How do you diagnose Spirocerca lupi eggs?
Fecal flotation (NaNO3 solution) Vomitus: thick-shelled, larvated, 34 x 13 μm
How do you diagnose Spirocerca lupi adults?
Vomitus
Necropsy
What is the DH of Oxyuris equi (pinworms)?
Equids
What is the distribution of Oxyuris equi?
Worldwide
What is the life cycle of Oxyuris equi?
Eggs L1 –> L2 –> L3 in eggs (4-5 days)
Cement fries, cracks; eggs fall off or are rubbed off
L3 in egg (infective) ingested by DH
L3 hatch in SI; feed on intestinal mucosa
3rd molt in mucosal crypts
L4 ventral colon
Adults in dorsal colon feed on gut contents
Female moves to anus
Female lays eggs in gelatinous substance, “cement”, under tail
What is the primary importance in pathology with Oxyuris equi?
Egg laying females
What does Oxyuris equi egg laying females do?
Travel to rectum
Females extrude through the host’s anus
Lay eggs on perineum in clumos contained in gelatinous material
Inflammation of cecum, colon
Describe L4 Oxyuris equi
Relatively large buccal cavity
Attach to intestinal mucosa
Feed by intestine plugs
Mucosal erosions –> little pathology
Describe Oxyuris equi adults
Free in intestinal lumen
Feed on gut contents
No pathology
What is the definitive method of diagnosing Oxyuris equi?
Scotch tape method
