Dictyocaulus is a genus of nematode parasites of the bronchial tree of horses, sheep, goats, deer, and cattle. Dictyocaulus arnfieldi is the lungworm of horses, and Dictyocaulus viviparus is the lungworm affecting ruminants.
Read more about Dictyocaulus: Dictyocaulus Viviparus: Lungworm of Cattle, Deer, Diagnosis of D. Viviparus Infection, Treatment of Lungworm Infections, D. Arnfieldi in Horses and Donkeys