A respiratory disease with morbidity and lethality rates respectively of 7.1% and 13.3% was diagnosed in 5-7 month-old beef calves from the central region of Rio Grande do Sul, Brazil. Clinical signs included anorexia, loss of weight, cough, tachypnea, dyspnea, abdominal respiration, and serous nasal discharge. Gross lesions found in the necropsy of two affected calves included pulmonary changes such as edema, emphysema and atelectasis which were associated with 8-10cm long, filiform nematodes with morphology compatible with Dictyocaulus viviparus within the bronchi. Histologically there were fibrinosuppurative bronchopneumonia, lympho-histiocytic and plasmacytic peribronchitis and peribronchiolitis, bronchiolitis obliterans and type II pneumocyte hyperplasia. Within bronchi and bronchioli lumina there were numerous adult specimens of D. viviparus. Within alveoli there were numerous eggs and larvae of this nematode surrounded by large numbers of eosinophils and few multinucleated giant cells.
diseases of cattle; lung worms; verminous pneumonia; parasitic bronchitis; dictyocaulosis; Dictyocaulus viviparus; pathology
