5 terms

Nematodes - Strongylida - Metastrongyloidea

Filarioididae, Angiostrongylidae, and Metastrongylidae
Tracheal worm
Oslerus osleri
Oslerus osleri
Dogs and wild carnivores.
ADULTS: Small, hair-like, grey, 0.5-1.0cm
LARVAE: L1 in feces or sputum, kinked tail but not accessory spine
LC: Direct; L1 ingested and all stages develop in lungs, infection through ingestion of regurgitated stomach contents, lung tissue or feces of infected dogs.
PPP: 10-18wks
SOI: Nodules with nematodes in lungs or lung tissue
PATH: Grey miliary nodules in lung parenchyma
CS: asymptomatic, hyperpnea
Dx: bronchoscope @ 2mos; L1 detected in feces or sputum; Baermann; Zn sulphate float
Tx: MCLs, sterilization
Aelurostrongylus abstrusus
IH: Snails & slugs
Paratenic: Birds, rodents, frogs
ADULTS: 1cm, slender
LARVAE: L1 in feces with kink or S-shaped tail
LC: Indirect; L3 infective, small greyish nodules in lung parenchyma
PPP: 6-12wks
SOI: Lung parenchyma and bronchioles
PATH: Low, small foci with greyish centers seen on postmortem
CS: Chronic mild cough, coughing following exercise or handling
Dx: fecal - floatation or baermann
Tx: Levamisole, ivermectin, control paratenic hosts
Muellerius spp.
Lung worm
FH: Sheep & goats
IH: Molluscs
Adults: brown, hair-like, 1-3cm, embedded in lung tissues, tail has an S-shaped kink
LC: Indirect. Females ovo-viviparous: L1 pass in feces and penetrate food of molluscan host, develop to L3. Sheep ingests mollusc during grazing, L3 liberated and migrated to lungs. Develop to adults in lymph nodes and lungs.
SOI: Alveoli of lungs
PATH: "lead shot" lesions embedded in lung tissue
CS: rarely causes signs of pneumonia in sheep. Heavy infections in goats serious.
Dx: L1 in fecal with Baermann
Tx: several anthelmintics, reported effective, control difficult because L3 live as long as mollusc
Metastrongylus spp
Lungworm of pigs
FH: Pig
IH: Earthworm
Adults: slender white nematodes, 6cm
Eggs: small with L1; irregular exterior; 51-63 x 33-42um > Strongyloides spp.
LC: Direct and Indirect. Eggs containing L1 are passed up he trachea, swallowed, and excreted in the feces, ingested by earthworm, develop to L3 (may stay there for years), earthworm consumed by pig, L3 released and migrate to mensenteric lymph nodes and molt, and from there they migrate via the lymphatic route to the lung; earthworm may not be obligatory.
PPP: 4wk
SOI: Bronchi and bronchioles
PATH/CS: lung migrations cause lesions, peribronchial lymphoid hyperplasia, chronic bronchitis, emphysema, marked coughing, nasal discharge and dyspnea, fatal cases can occur
Dx: eggs with L1 in fecal examination
Tx: young pigs severely affected, longlasting exposure due to the earthworm reservoir, several anthelmintics approved.