Changes

=Lungworm - ''Dictyocaulus arnfieldi''=

=Lungworm - ''[[Dictyocaulus arnfieldi]]''=

==Introduction==

==Introduction==

This equine nematode parasite infecting the respiratory tract has worldwide distribution, with high infection prevalence in donkeys. Donkeys are assumed to be the natural host of this parasite. It is commonly patent in the donkey, whereas in the horse patency is uncommon. The worms are well adapted to living in the donkey where they grow to maturity and lay eggs, while in most cases presenting few clinical signs. In the [[Horses#Lungworm|horse the parasite]] rarely develops to maturity, but severe tissue reaction stimulates chronic coughing. There are, however, reports that ''D. arnfieldi'' can occasionally produce patent infection in the horse (Round, 1976).

This equine nematode parasite infecting the respiratory tract has worldwide distribution, with high infection prevalence in donkeys. Donkeys are assumed to be the natural host of this parasite. It is commonly patent in the donkey, whereas in the horse patency is uncommon. The worms are well adapted to living in the donkey where they grow to maturity and lay eggs, while in most cases presenting few clinical signs. In the [[Dictyocaulus arnfieldi|horse the parasite]] rarely develops to maturity, but severe tissue reaction stimulates chronic coughing. There are, however, reports that ''D. arnfieldi'' can occasionally produce patent infection in the horse (Round, 1976).

The life cycle of the parasite involves ingestion of infective third stage larvae that migrate via the mesenteric lymph nodes and thoracic duct. Larvae infiltrate the alveoli causing low-grade inflammation. Adult worms grow up to 8 cm long in the bronchi and can block the small airways. The pre-patent period is approximately 13 weeks. The first-stage larvae are passed in the faeces and take as little as three days to develop into infective third-stage larvae (L3). L3 can survive for prolonged periods in shady

The life cycle of the parasite involves ingestion of infective third stage larvae that migrate via the mesenteric lymph nodes and thoracic duct. Larvae infiltrate the alveoli causing low-grade inflammation. Adult worms grow up to 8 cm long in the bronchi and can block the small airways. The pre-patent period is approximately 13 weeks. The first-stage larvae are passed in the faeces and take as little as three days to develop into infective third-stage larvae (L3). L3 can survive for prolonged periods in shady