Craniomandibular osteopathy (CMO) in Terriers
Craniomandibular osteopathy (CMO) is a genetic bone disease altering form and function of the bones of the skull and jaw. This very painful disease occurs when the dogs are 4 to 7 months old, may recur every 2 to 4 weeks, and is self-limiting. So far CMO could be diagnosed only by radiologic examination but for the first time a DNA based diagnosis is now possible. We have identified a causative mutation for CMO in West Highland White, Scottish, and Cairn terriers which is autosomal dominant inherited showing incomplete penetrance and help to explain the reported differences in the severity and duration of CMO among the affected dogs. Dogs that are homozygous mutant (two copies of the mutation; CMO-2) have a comparably higher risk to develop CMO. Dogs heterozygous for the mutation (one copy of the mutation; CMO-1) might rarely also develop clinical signs; they are classified at low risk. Since CMO occurs sporadically also in other dog breeds we ask breeders and owners of affected dogs to donate samples of the affected individuals to study a possible genetic etiology.