Dictyocaulus filaria

Dictyocaulus filaria
Class	Nematoda
Super-family	Trichostrongyloidea
Genus	Dictyocaulus
Species	D. filaria

Also known as:

Sheep lungworm

Hosts

Sheep and goats.

Identification

D. filaria are of the superfamily Trichostrongyloidea. The adult worms are white, and the intestines can be clearly seen as a longitudinal dark bands running down the worm. The females are around 8cm in length, and the males are 6cm in length.

Life Cycle

The life cycle of D. filaria is very similar to that of Dictyocaulus viviparus. It is a direct life cycle, and the females are ovo-vivparous. The females lays eggs which contain mature larvae. The eggs hatch quickly, and the L3 larvae are ingested by the host. The larvae then travel to the mesenteric lymph nodes where they moult. They then travel to the lungs via the blood or lymphatic system.

The final transformations occur in the bronchioles, and the adults fully mature in the bronchi, causing Bronchitis.

L1 larvae are then coughed and swallowed. The larvae enter the intestinal tract, and are passed out in the faeces.

The prepatent period of D. filaria is 4-5 weeks.

References

Taylor, M.A, Coop, R.L., Wall,R.L. (2007) Veterinary Parasitology Blackwell Publishing