Craniomandibular osteopathy is a disease of several breeds of dogs, principally West Highland White and Scottish terriers. It is characterized by a non-neoplastic proliferation of bone on the ramus of the mandible and/or the tympanic bulla. The disease in various respects resembles Paget's disease and infantile cortical hyperostosis of humans. A retrospective pedigree analysis of a kindred of West Highland White terriers was performed to determine if the trait was inherited and to determine mode of inheritance. This study indicated that in West Highland White terriers, the condition is an autosomal recessive trait.