Spirurids Flashcards
Where do thelazia live?
On the surface of the eye in birds and mammals - lacrimal ducts & conjunctiva
Where are spirocera found?
Esophagus of dogs
Where is physaloptera found?
Stomach of carnivores
Where is physocephalus found?
Stomach of pigs
Where are draschia & habronema found?
Stomach of horses
This is a fresh worm, what is it?
Spirocerca
Bright red when fresh
How can spirocerca be transmitted?
Intermediate hosts = dung bettles
OR
Paratenic hosts = mice, chickens, lizards
What is the most common form of transmission for spirocerca?
Eating a paratenic host
What is the life cycle for spirocerca lupi?
Adults in fibrous nodules of the esophagus and stomach
Females produce eggs -> L1 shed in feces
Egg with L1 ingested by intermediate host
Larva hatches inside intermediate host
Dog ingest L3 in intermediate host OR paratenic host
L3 released in the stomach
Larval migration through stomach wall
Into blood vessels
Enters visceral arteries & aorta
Cuases damage
Migrates to esophagues
Forms nodules
When is L3 released from the intermediate host or paratenic host in spirocerca lupi?
L3 released in the STOMACH
Where do adults of spirocerca lupi develop?
Submucosal nodules
Where do females lay eggs for spirocerca lupi?
Fistula in nodules
- What is THE characteristic lesion seen with spirocerca lupi?
- Is this lesion caused by larval migration OR the adults?
- Aneurysms in the thoracic aorta
- Caused by larval migration
What types of damage do the females cause for spirocerca lupi?
Nodule formation in the wall of esophagus, stomach, aorta
Nodules are NOT granulomas
What are the clinical signs of spirocercosis?
Dysphagia
Vomiting, regurgitation
Emaciation
Mild anemia (due to hemorrhage from esophagel lesions)
What are the 4 main complications seen with spirocercosis?
Esophageal nodules –> fibrosarcoma, osteosarcoma
Aneurysm of thoracic aorta –> sudden death
Hypertrophic osteopathy
Caudal thoracic vertebral spondylitis
What is the life cycle of Physaloptera?
Adults attached to stomach mucosa
Eggs with L1 passed in feces
Eggs ingested by intermediate host
Infective L3 develops in arthropod
Definitive host ingests arthropod OR paratenic host
Develop directly into adults (NO LARVAL MIGRATION)
What is THE characteristic clinical sign of physaloptera?
Chronic, intermittent vomitting
What are other clinical signs of physaloptera?
Mild gastritis
Mucosal erosions
Anorexia
Weight loss
Melena
Anemia
Eosinophilia
What is the treatment of physaloptera?
ALL EXTRA LABEL:
Pyrantel
Fenbendazole
Ivermectin
MANUAL REMOVAL
What is the life cycle of physocephalus?
Adults in stomach attached to mucosa
Egges ingested by intermediate host
L1 hatches inside intermediate host
Develops into infective L3
Pig eats intermediate host with L3
L3 released in the stomach
Develop into adults
What are the symptoms of physocephalus?
USUALLY ASYMPTOMATIC
Mild catarrhal gastritis
What is the treatment for physocephalus?
Ivermectin
Which are bigger, Drashia adults or Habronema adults?
Drashia = 13 mm
Habronema = 22-25 mm
- What are the intermediate hosts associated with Habronema?
- What is the intermediate host associated with Drashcia?
- Common housefly & stable fly
- Common housefly
What is the life cycle of Habronema?
Adults in stomach
Lay eggs
L1 passed in feces
Maggots serve as intermediate host, ingest L1
L1 develops into L3 inside maggot
L3 migrates to adult fly mouthparts
L3 deposited on warm, moist fly feeding sites
Where might Habronema L3s be deposited during fly feedings?
LIPS
NOSTRILS
CONJUNCTIVA
OPEN WOUNDS
GENITALIA
Which causes nodules in the stomach, Drashcia OR Habronema?
Drashcia
Can perforate, hemorrhage, interfere with pyloric valve function
Cutaneous habronemiasis is usually associated with what, Draschia OR Habronema?
Drashcia
What 2 conditions are associated with a Habronema infection?
Summer sores (cutaneous habronemiasis)
Granular conjunctivitis of the medial canthus of the eye
What is characteritis of Dracunculus insignis?
What larval stage is this characteristic present?
Very long pointed tail
L1
What are the definitive hosts of Dracunculus insignis?
Raccoon
Mink
What are the accidental hosts of Dracunculus insignis?
Is it zoonotic?
Dogs
No
What are the intermediate hosts of Dracunculus insignis?
Arthropods
Cyclops or copepod: a microscopic crustacean
What are the paratenic hosts of Dracunculus insignis?
Frogs +/- fish
What is the life cycle of Dracunculus insignis?
Definite host ingests intermediate host OR paratenic host
Larvae migrate to SQ tissues
Develop into adults
Males die after mating
Females in SQ tissues of lower legs, thorax, and abdomen
Produce substance that induces blisters to form
Blisters ulcerate
