Abnormal length of respiratory cilia in a pig. An ultrastructural study

The authors report the first case of abnormal length of respiratory cilia in a domestic animal (18 microns versus normal length about 5 microns). These cilia lie on the carpet of cilia of normal length. The width of some of these cilia is also abnormal, measuring 0.5-0.6 microns. Other cilia have hook-shaped tips that could be responsible for an effective beat. We suggest that the ineffective ciliary beat could also be due to the undulating movements of abnormally long cilia, and stress the need for further morphological and biochemical studies of respiratory cilia in pigs. Respiratory pathology is a very common finding in pigs and is responsible for remarkable economical losses.