Genetic basis of Craniomandibular Osteopathy - is an inherited developmental bone disorder primarily affecting young, growing dogs, particularly terrier breeds such as West Highland White Terriers and other related breeds.
Diagnosis - Physical examination showing jaw swelling and pain. Diagnostic imaging (X-rays, MRI) revealing characteristic abnormal new bone formation on the mandible and skull. Bone biopsy can confirm bone remodeling consistent with CMO. Laboratory tests are generally non-specific and not diagnostic.
Clinical Signs - Excessive, irregular bone growth occurs around the jaw and skull, especially on the lower jaw (mandible) and temporomandibular joint. Common signs appear between 3-7 months of age and include: Painful swelling of the jaw and base of the skull. Difficulty opening the mouth. Reluctance to eat or difficulty chewing. Drooling and oral discomfort. Fever and lethargy. Possible swelling or bony changes on other skull bones or even long bones leading to lameness.
Diagnosis - Physical examination showing jaw swelling and pain. Diagnostic imaging (X-rays, MRI) revealing characteristic abnormal new bone formation on the mandible and skull. Bone biopsy can confirm bone remodeling consistent with CMO. Laboratory tests are generally non-specific and not diagnostic.
Treatment - There is no cure; treatment is supportive: Pain management with non-steroidal anti-inflammatory drugs (NSAIDs) or other analgesics. Assisted feeding if eating is difficult. Fluid therapy if necessary. Most dogs improve as bone growth slows and regresses. Prognosis is generally good except for rare cases with joint fusion.
Why This Matters to Breeders and Vets - Because of the inherited nature, affected dogs should not be bred to prevent passing the disorder. Early recognition and supportive care enhance quality of life for affected puppies. Awareness allows veterinarians to differentiate CMO from other jaw or bone diseases.