Craniomandibular osteopathy (CMO)


Craniomandibular osteopathy is a benign, proliferative, bone disease seen in young dogs. It manifests between 4 to 8 months of age and the symptoms vary from mild to severe. The excessive proliferation causes bony lesions typically on mandible but occasionally also on other parts of the skull and long bones. Typical symptoms include pain, swelling of the jaw, difficulty opening the mouth and eating sometimes accompanied by periodical fever. Diagnosis is made by radiography. Medication is usually prescribed to relieve pain and symptoms. Usually, the symptoms resolve by the age of one year when the growth period is finished.


CMO is an inherited condition and occurs commonly in some terrier breeds like West Highland white, Cairn and Scottish terrier. It has been reported in many other breeds as well (e.g. Boston and Bull terrier, Labrador and Curly Coated Retriever, Great Dane, Bullmastiff, Doberman Pinscher, Shetland sheepdog, English Bulldog, Boxer, Pyrenean mountain dog and Akita).


We have identified the genetic variant associated with the disease in West Highland White, Cairn and Scottish terriers. 


Further information on CMO research: Marjo Hytönen (marjo.hytonen(at)