Craniomandibular Osteopathy

The craniomandibular osteopathy (also 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 first described in 1958 by Littleworth.

Occurrence

Craniomandibular osteopathy occurs primarily in West Highland White and in closely related breeds such as Cairn and Scottish Terriers . Individual cases have also been described for other breeds such as the German Shepherd , Labrador Retriever , Doberman , Great Dane and German Wirehaired Pointer .

Clinical picture

The disease begins around 4 months of age. The affected animals show severe pain in the temporomandibular joint region , touching the head is no longer tolerated. They avoid opening the catch and feed intake is greatly reduced or even stopped, despite the appetite being preserved. Occasional attacks of fever can also occur. The symptoms initially worsen increasingly, but from the age of one year the bone changes recede spontaneously.

X-ray examination

X-rays show bone growth and sclerosis on the lower jaw , temporomandibular joint or bulla tympanica (bony capsule around the middle ear ). Occasionally, changes in the limb bones can also be detected. Osteolytic processes or infiltration of the surrounding tissue do not occur.

At the beginning, the bone changes are only minor and can therefore be overlooked. Initially, only flatly layered formations are formed, which cause slight irregularities in the bone contours of the lower jaw body and bulla tympanica. Angled exposures in which the head is stretched and turned about 30–40 ° to the side are particularly suitable for demonstrating such minor changes. As the disease progresses, the osseous trabeculae dissolve, causing cloudy shadows and finally significant thickening. They usually show a layered structure, which is caused by the progressive disease progression.

In the differential diagnosis , benign ( osteomas ) or malignant ( osteosarcomas ) bone tumors as well as the calvarial hyperostosis syndrome must be excluded.

pathology

Pathohistologically, bone resorption by osteoclasts occurs , with the lamellar bone being replaced by woven bone . The bone marrow in the cavities of the substantia spongiosa is replaced by connective tissue that is well supplied with blood. Inflammatory cells can be found at the edge of the bone growth.

treatment

A causal therapy is not possible. The aim of treatment is to relieve pain until spontaneous remission occurs . Anti-inflammatory drugs such as carprofen , meloxicam or metamizole are mostly used here. Some authors use prednisolone as an alternative .

Inheritance and breeding hygiene

In Scottish, Cairn and West Highland White Terriers, the disease is associated with a mutation of a gene on chromosome 5. The inheritance in these breeds is simply dominant with incomplete penetrance . The penetrance in dogs that are purely inherited for the mutation is 57%. A genetic test is available for these three breeds .

There is currently no genetic test for the other races affected by craniomandibular osteopathy. Due to the suspected hereditary genesis, affected animals should not be used for breeding. Matings from which CMO animals emerged should not be undertaken again. Stur et al. (1991) also recommend excluding healthy siblings of sick animals from breeding.

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literature

• W. Beck: Cranio-mandibular osteopathy. An impressive clinical picture of various terriers. In: Small animal concrete 5 (2002), pp. 9–12.
• Max Hildenbrand: Case report: Craniomandibular osteopathy in a German Shepherd. In: Kleintierpraxis 37 (1992), pp. 779-784.
• Irene Stur and others: Cranio-mandibular osteopathy in the West Highland White Terrier. In: Kleintierpraxis 36 (1991), pp. 491-500.

Individual evidence

1. ↑ MCG Littleworth: Tumor-like exostoses on the bones of the head in puppies. In: Vet. Rec. 70 (1958), pp. 977-982.
2. ↑ Cord Drögemüller: Genetic test for craniomandibular osteopathy (CMO) in three Scottish terrier breeds.

Web links

• Skull of an affected dog (click on the picture for full view)

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !