Craniomandibular osteopathy
The craniomandibular osteopathy (including cranio- mandibular osteopathy, CMO, or Osteopathia craniomandibularis hypertrophicans ) is a hereditary, very painful bone disease of the skull in domestic dogs, especially in West Highland White Terriers. The disease was described in 1958 by Littleworth first time.
Occurrence
The craniomandibular osteopathy is mainly found in West Highland White and with closely allied with it breeds like Cairn and Scottish Terriers. Single cases have been described for other breeds like German Shepherd, Labrador Retriever, Doberman, German Mastiff and German Wirehaired Pointer.
Clinical picture
The disease starts from the age of about 4 months. Affected animals show a strong pain in the TMJ region, touching the head are no longer tolerated. You avoid having to open the capture and feed intake, despite preserved appetite, greatly reduced or even ceased. Occasionally, fever may occur. Symptoms are worse at first increasing, over the age of one year, however, the bone changes form again spontaneously.
X-ray
Radiograph and new bone sclerosis indicate lower jaw, jaw joint, or bulla ( bony capsule around the middle ear ). Occasionally, changes in the limb bones are detectable. Osteolytic processes or infiltration of surrounding tissues do not occur.
Initially, the bone changes are not very pronounced and may therefore be overlooked. Initially, only form flat layered proliferations that cause a slight irregularity of the bone contours of mandibular body and bulla. For the detection of such low-grade changes are primarily oblique projections in which stretched the head and about 30-40 ° turned to the side. In the further course of the disease occur by dissolution of the trabeculae on cloudy shading and finally significant thickening. They usually exhibit a layered structure, which is caused by the batchwise disease.
The differential diagnosis must be excluded benign ( osteomas ) or malignant ( osteosarcoma ) bone tumor as well as Cavarial - hyperostosis syndrome.
Pathology
Histologically, there is a bone resorption by osteoclasts, the lamellar bone is replaced by woven bone. The bone marrow cavities of the cancellous bone is replaced by highly vascularized connective tissue. At the edge of the new bone inflammatory cells are found.
Treatment
A causal therapy is not possible. The goal of treatment is to relieve the pain for the time until spontaneous remission. Here anti-inflammatories such as carprofen, meloxicam or dipyrone are used mostly. Some authors use an alternative prednisolone.
Inheritance and breeding hygiene
In Scottish, Cairn and West Highland White Terrier, the disease is associated with a mutation of a gene on chromosome 5. The inheritance is in these breeds simply dominant with incomplete penetrance. The penetrance is homozygous for the mutation in dogs 57%. For these three races is a genetic test available.
So far there is no genetic test for the other countries affected by craniomandibular osteopathy races. Because of the suspected hereditary genesis affected animals should not be used for breeding. Matings from which CMO animals should not be made again emerged. Stur et al. (1991 ) also recommend the disqualifying healthy siblings of affected animals.