Observations on the pathology of tracheal collapse in dogs

The pathology of tracheal collapse in dogs is described. Ten dogs were studied and in all cases there was macroscopic and histological evidence of flattening of the tracheal cartilage and peripheral lung disease. It was considered that the essential lesion was a removal of organic matrix from the cartilage. It was thought that this was probably congenital in origin but required the presence of concurrent lung disease as a triggering factor before clinical signs developed.