Lecture Quiz 5 - Exam 2 - Nematode - Order: Spirurida

Front 1

Describe the Order Spiruirda.

Back 1

1. Large diverse group
2. 6 superfamilies
3. "Spirura" means spiral tail
4. Females produce eggs containing an L1: exception - superfamily Filarioidia produces L1 called microfilaria
5. Indirect life cycle - infective L3 develops in intermediate host; intermediate host is usually an arthropod

Front 2

Describe the superfamily Dracunculoidea: Dracunculus insignis

Back 2

Common names: guinea worm, fiery serpent or dragon worm

Fairly large nematodes: females are 8-10 inches long and males are 1 inches long

L1 have very long pointed tail

Front 3

Describe the definitive and intermediate hosts of Dracunculus insignis.

Back 3

Definitive hosts: raccoon, mink; dog is accidental host; NOT zoonotic

Intermediate host: cyclops or copepod: a microscopic aquatic crustacean

Paratenic hosts: frogs; +/- fish

Front 4

What is the life cycle of Dracunculus insignis?

Back 4

Definitive host ingests IH or paratenic host --> larvae migrate to subcutaneous tissues and develop into adults --> males die after meeting --> females are in SC of lower legs, thorax or abdomen --> Produce substance that induces blister to form in overlying skin --> blister ulcerates --> female exteriorizes uterus on contact of blister or ulcer with water and discharges L1 into water --> IH ingests L1

Front 5

What is the history and clinical signs of Dracunculus insignis?

Back 5

Outdoor exposure, access to pond, river, stream

Presence of nodules, blisters, non-healing skin ulcers on lower body; expose lesion to water --> female deposits L1

Front 6

What is the diagnosis and treatment of Dracunculus insignis?

Back 6

Diagnosis: centrifuge water, examine sediment for Dracunculus L1; long pointed tail

Treatment: manual (surgical) removal of female; no treatment; female dies after all L1 expelled and ulcer eventually heals

Front 7

Describe the superfamily Physalopteroidea: Physaloptera spp.

Back 7

Stomach worms of dogs and cats:
Physaloptera rara - dogs and cats: cuticle projects beyond anterior end to form a "collar"
Physaloptera praeputialis - cats only: cutical forms prepuce-like structure at posterior end

Occur in stomach of definitive host; can also occur in anterior duodenum near gastric valve; usually firmly attached to mucosa

Stout robust worms - 2 inches long; pink-white when fresh; often coiled; male has 2 lateral posterior posterior alae

Front 8

What is the life cycle of Physaloptera spp?

Back 8

Adults attach to stomach mucosa --> feed --> Eggs with L1 passed in feces (oval thick-walled; colorless shell) --> Egg with L1 ingested by IH (beetles) --> infective L3 develops --> definitive host ingests IH --> L3 develops to adult in stomach (no larval migration)

Front 9

What are the clinical signs and lesions of Physaloptera spp?

Back 9

Usually asymptomatic
Can cause mild gastritis --> chronic intermittent vomiting, anorexia: possible black, tarry feces
Mucosal erosions and inflammation; attachment sites bleed after worms detach

Front 10

What is the diagnosis of Physaloptera spp?

Back 10

Endoscopy: search stomach +/- duodenum for worms; usually only a few worms present; can detect non-patent infection

Front 11

What is the treatment of Physaloptera spp?

Back 11

1. Manual removal via endoscopy
2. Anthelmintics

Front 12

Describe the superfamily Thelazioidea: Thelazia spp.

Back 12

1. Eye worms
2. Intermediate hosts: flies
3. Seasonal

Front 13

What are the Thelazia spp?

Back 13

Thelazia lacrymalis - most common in 1 to 3 year old horses

Thelazia spp of ruminants - not common in MW

Thelazia californiensis: in dogs and cats (vector - flies)

Front 14

What is the structure of Thelazia?

Back 14

1. Small milky-white worms
2. Males: .8 - 1.2 cm with unequal spicules
3. Females: 1.4 - 1.8 cm

Location: beneath 3rd eyelid, in lacrimal ducts and conjunctival sac

Front 15

What is the life cycle of Thelazia spp?

Back 15

Adult females produce thin-shelled egg containing a larva --> egg and/or larva taken up by fly feeding on eye secretions --> infective L3 develops in fly (2-4 weeks) --> fly deposits L3 on new host when feeding

Front 16

What are the clinical signs of Thelazia spp?

Back 16

Infection usually asymptomatic
Can include: increase lacrimation - cuticular striations irritating; conjunctivitis and keratitis; plugged lacrimal ducts (inflammatory cells and necrotic debris); photophobia; corneal opacity

Front 17

How do you diagnose Thelazia infection?

Back 17

Inspect eyes for worms - ventral surface of 3rd eyelid and flush lacrimal duct; might find larvae/eggs in tears

Front 18

Explain Spirocerca lupi.

Back 18

Esophageal worm
Definitive host = canines
Intermediate hosts = dung beetles

Adults - short to medium length; stout and coiled; bright red when fresh

Front 19

What is the life cycle of Spirocerca lupi?

Back 19

Adults in fibrous nodules in stomach or esophageal wall --> females produce eggs with L1 --> Egg with L1 ingested by coprophagous beetles --> dog ingests L3 in IH or paratenic host --> L3 released from IH or paratenic host in stomach --> larval migration: penetrate through stomach wall into blood vessels and enter adventitia (outer layer) of visceral arteries and aorta

Front 20

What is the larval migration of Spirocerca?

Back 20

Migrate directly from aorta to adjacent distal esophagus or stomach: adults develop in submucosal nodules --> fistula (port hole) in nodule for eggs to exit

Front 21

What kind of lesions are found due to Spirocerca lupi?

Back 21

Larval migration in aorta: hemorrhage, inflammation, necrosis and abscesses; lesions heal with time after larvae move on; pathognomonic lesions: aneurysms and stenosis in thoracic aorta

Adults: induce nodule (granuloma) formation in wall of esophagus, stomach or rarely aorta

Front 22

What are some clinical signs of Spirocerca lupi?

Back 22

1. Dysphagia
2. Vomiting, regurgitation
3. Chronic infection --> emaciation
4. Possible mild anemia

Front 23

What complications are there from Spirocerca lupi?

Back 23

1. Aneurysm in thoracic aorta: rupture = sudden death

2. Esophageal nodules --> neoplastic

3. Secondary or Hypertrophic Pulmonary Osteoarthropathy (HPO): response to chronic intra-thoracic disease; periosteal new bone formation along shaft of long bones

Front 24

How do you diagnose Spirocerca lupi?

Back 24

Detect egg containing L1 in FRESH feces or vomit

Eggs not present in feces until/unless granuloma is patent

Front 25

Describe Spirocerca lupi eggs.

Back 25

1. Small and oval
2. Thick-shell
3. Contain coiled L1 in fresh feces
4. Smaller than Physaloptera eggs

Front 26

Describe Gongylonema pulchrum.

Back 26

Esophageal worm, gullet worm

Occurs in cattle, sheep, goats, pigs and possibly horses or humans

Adults: long, thin worm, 6-15 cm; wart-like structures (bosses) on cuticle of anterior

Front 27

What is the life cycle Gongylonema pulchrum?

Back 27

Eggs with L1 passed in feces --> eaten by IH (dung beetles, cockroaches) --> L3 develops in 1 month --> new host ingests IH --> believes L3 released in stomach and migrates cranially

Front 28

Describe Physocephalus and Ascarops.

Back 28

Stomach worms of swine; stout worms ~ 1 inch long; eggs similar to Physaloptera; occur worldwide

Front 29

What is the life cycle of Physocephalus and Ascarops?

Back 29

Adults in stomach: attached to mucosa or in mucus --> eggs ingested by dung beetles (IH) --> L1 hatches, develops into infective L3 --> pig eats IH with L3 --> L3 released in stomach and develops to an adult

Front 30

Describe Physocephalus eggs.

Back 30

1. Elongated elliptical egg with thick shell
2. 12-26 X 31-45 um
3. Contains an L1
4. Differentiate from other eggs with L1

Front 31

Describe the superfamily Habronematoidea.

Back 31

Equine stomach worms: Habronema muscae, Habronema majus, and Draschia megastoma

Occur near margo plicatus

Front 32

Structure of Equine Stomach worms.

Back 32

1. Draschia adults: ~13 mm long; funnel-shaped buccal cavity and anterior collar; associated with fibrous nodules in stomach

2. Habronema adults: ~22-25 mm long; cylindrical buccal cavity; no stomach nodules; tail of males usually coiled

Front 33

What is the life cycle of equine stomach worms?

Back 33

Adults in stomach lay eggs --> eggs and/or L1 passed in feces --> fly larvae serve as IH; ingest L1 --> L1 develops to L3 --> L3 migrate to adult fly mouth parts and deposited on warm, moist fly feeding sites

Front 34

What are cutaneous habronemiasis?

Back 34

Usually associated with Draschia; occurs during fly season

Larvae don't develop to adults unless ingested by horse

Lesions heal spontaneously after temperatures fall below freezing

Front 35

Describe the superfamily Filarioidea.

Back 35

Adults: long, thin, white or cream-colored; minimal distinguishing structures; males may have spiral tail; NOT in GI tract; tissue spaces, body cavities, blood or lymphatic vessels

Viviparous females produce L1 - L1 called microfilaria (mff); L1 circulate in blood or lymph or accumulate in skin

Indirect life cycle with arthropod IH