Dictyocaulosis is a parasitic disease caused by the lungworm Dictyocaulus viviparus, which is globally distributed. It can cause respiratory illness, particularly in cattle during their first grazing season, and has a significant economic impact. Dictyocaulosis is associated with grazing, and its prevalence varies depending on the climate, occurring more frequently in temperate and humid regions. The pathogenesis and lesions result from larval migration and the presence of adult nematodes in the respiratory tract. The development of acute, subacute, or chronic conditions depends on factors such as parasitic load, the animal’s age, and immune status. The most common clinical signs are coughing and dyspnea. Laboratory diagnosis is based on coprological analysis (to detect L1 larvae in feces) and commercial ELISA methods in serum or milk (useful 4–5 weeks post-infection). Effective treatments include benzimidazole-carbamates, probenzimidazoles, and macrocyclic lactones, which should ideally be administered after the onset of clinical signs or following a positive diagnostic test. A live vaccine using irradiated L3 larvae (Bovilis Huskvac®) is available as a prophylactic measure in humid countries where the disease is endemic and infections may occur year-round.