VPA 211: General Veterinary Parasitology and Helminthology (3+1)

MUELLERIUS CAPILLARIS

Location: Lungs

Host: Sheep, goats and chamosis

Morphology

• Male 12-14mm long and female 19-23 mm long.
• The posterior end of the male is spirally coiled and there is no bursa, but a number of papillae surround the cloacal opening.
• The spicules are 0.15mm long.
• The eggs measure about 100x20 µm.

Life cycle

• The eggs develop in the lungs of the host and the first stage larvae are passed in the faeces.
• The tail of the larvae has an undulating and dorsal spine.
• They require snail intermediate host eg: Species of the nude slugs Limax, Agriolimax and Arion, and snails Helix and succina.
• Infective larvae can live in snails one week even after death of snails.

Pathogenesis

• This parasite is usually not found in lambs or kids under six months of age. Thereafter the prevalence increases with age and in goats may reach 100% by three years of age.
• The worms produce greyish nodules up to 2cm in diameter.
•  Smaller separate foci are formed by the eggs which are surrounded by leucocytes and epithelioid cells.
• An adenoma-like proliferation of the bronchial epithelium is seen in some cases.
• In goats it causes widespread interstitial pneumonia.

Diagnosis

• Finding the larvae in fresh faeces. Treatment: Albendazole 5 mg/kg.