The clinical presentation and progression (over 9 months to 13 years) of congenital keratoconjunctivitis sicca and ichthyosiform dermatosis (CKCSID) in the Cavalier King Charles spaniel dog are described for six new cases and six previously described cases. Cases presented with a congenitally abnormal (rough/curly) coat and signs of KCS from eyelid opening. Persistent scale along the dorsal spine and flanks with a harsh frizzy and alopecic coat was evident in the first few months of life. Ventral abdominal skin was hyperpigmented and hyperkeratinized in adulthood. Footpads were hyperkeratinized from young adulthood with nail growth abnormalities and intermittent sloughing. Long-term follow-up of cases (13/25) is described. Immunomodulatory/lacrimostimulant treatment had no statistically significant effect on Schirmer tear test results, although subjectively, this treatment reduced progression of the keratitis. Histopathological analysis of samples (skin/footpads/lacrimal glands/salivary glands) for three new cases was consistent with an ichthyosiform dermatosis, with no pathology of the salivary or lacrimal glands identified histologically. Pedigree analysis suggests the syndrome is inherited by an autosomal recessive mode.