Craniomandibular Osteopathy (CMO) is an inherited bone disease affecting West Highland White Terriers, Cairn Terriers and Scottish Terriers. CMO is also know as Lion Jaw. The disease is characterised by excess bony growth in young dogs. CMO affects the mandibles (jaws), sometimes the temporomandibular joints, occasionally skull bones and more rarely long bones of the legs.
Clinical symptoms typically begin between 4 and 8 months of age and include periodic intense jaw pain, swelling of the jaws, difficulty eating, pain when opening the mouth and drooling. A lump of extra bone on the mandibleand very often noticeable.
The condition generally disappears spontaneously about a year after symptoms are first seen.