Immotile cilia syndrome in two Old English Sheepdog litter‐mates

Two Old English Sheepdog litter‐mates with chronic respiratory disease since birth had ultrastructural abnormalities of their respiratory tract cilia. The ciliary defects included lack of inner dynein arms, abnormal radial spokes and nexin links, and microtubule doublet displacement. Similar ciliary defects in man result in immotile cilia with the subsequent development of sinusitis, bronchitis or bronchiectasis, male sterility, and, in some cases, situs inversus. Both dogs had sinusitis and bronchiectasis, and one of the dogs also had situs inversus.