Metastrongylosis and stephanurosis of suids Flashcards
(25 cards)
What is the taxonomic order of Metastrongylus spp. & Stephanurus dentatus ?
Strongylida
List the Metastrongylus spp.
Metastrongylus pudendotectus
Metastrongylus apri
Metastrongylus salmi
Metastrongylus confusus
Metastrongylus madagascariensis
Metastrongylus asymmetricus
What is the final host (FH) of Metastrongylus spp. and Stephanurus dentatus?
pig
What is the intermediate host (IH) of Metastrongylus spp. & Stephanurus dentatus?
Earthworm
can be PH in Stephanurus dentatus
Where in the final host does Metastrongylus spp. localize?
Lungs – bronchi and bronchioles
Describe the morphology of the mouth of Metastrongylus spp.
Up to 6 cm
Mouth with 6 lips and hook
Male: Well-developed bursa, long spicules ending in a hook-like structure
Female: Tail bent in ventral direction. Oviviparous
Describe the egg of Metastrongylus spp.
Small, oval, symmetrical, 3 thick shells, rough surface, embryonated with L1 inside, transparent
How is the life cycle of Metastrongylus spp.?
Embryonated eggs in airwaysof FH are coughed up, swallowed, and passed in faeces
L1 hatches, ingested by IH, and develops into infective L3 (can remain infective for years)
FH ingest IH, L3 is released in the stomach, burrows through the gut wall, and migrates via lymphatic system/bloodstream to heart and lungs to mature into adults
Indirect, PP: 2-4 weeks
Pathogenesis of Metastrongylus species
- In bronchi/bronchioles: Chronic catarrhal & eosinophilic bronchiolitis & bronchitis, bronchial muscular hypertrophy. Emphysema and mucous hypersecretion occur later.
- After 6 weeks of infection: Chronic bronchitis and emphysema are established, with nodules in the lungs
Which pigs are commonly affected by Metastrongylus spp.?
Epidemiology
- Pigs 4–6 months of age
- Pigs on pasture
What clinical signs are seen with Metastrongylus spp. infection?
- Coughing, poor growth
- Heavy infection in young animals: Coughing, dyspnoea, and nasal discharge
How can Metastrongylus spp. be diagnosed?
- Embryonated eggs in faecal flotation (Breza method)
- Ovoscpic method
- Necropsy: Adults in lungs
What are effective treatments for Metastrongylus spp.?
Fenbendazole and Ivermectin
How can Metastrongylus infection be controlled & prevented?
Control: difficult because earthworms act as intermediate hosts in the soil
Prevention: Prevent pigs’ access to soil containing earthworms or larvae; farrow & raise outdoor pigs on clean pastures (avoids heavy infection)
Where is Metastrongylus spp. found geographically?
Worldwide
Name lungworm and kidney worm of pigs
- Metastrongylus spp.
- Stephanurus dentatus
Where does Stephanurus dentatus localize in the final host?
Kidney and perirenal fat
What is the size of male Stephanurus dentatus?
- male: 20–30 mm
- female: 30–45 mm
What is the Life cycle of Stephanurus dentatus
3 ways pigs can get infected with Stephanurus dentatus:
- L3 penetrates the skin of the final host
- Ingestion of eggs containing L3
- Ingestion of earthworm containing L3 (PH/IH)
L3 larvae migrate from SI → via portal circulation to liver
Some migrate to peritoneal cavity
Larvae from skin infection migrate to lungs → coughed up and swallowed → reach intestines
PP: 6–19 months
What pathogenesis is associated with Stephanurus dentatus?
- Percutaneous infection: nodules in skin, swelling and enlargement of regional lymphatic nodules.
- Migrating larvae can produce abscesses and liver cirrhosis.
- Adult worms produce cysts in the kidney. The ureter gets thickened and becomes impassable
What are the clinical signs of Stephanurus dentatus infection?
Weight loss, ascites, and pelvic limb paralysis
How is Stephanurus dentatus diagnosed?
Eggs found in urine
Necropsy: adult cysts in perirenal fat
What drugs are used to treat Stephanurus dentatus?
Levamisole, Ivermectin, Benzimidazoles
What control measures can help prevent Stephanurus dentatus infection?
Good hygiene
