Affects: Dogs
Craniomandibular osteopathy, also known as lion's jaw, is a developmental disease in dogs causing extensive bony changes in the mandible and skull. In this disease, a cyclical resorption of normal bone and replacement by immature bone occurs along the inner and outer surfaces of the affected bones. It usually occurs between the ages of 3 and 6 months. Breeds most commonly affected include the West Highland White Terrier, Scottish Terrier, Cairn Terrier, and Boston Terrier. It is rare in large-breed dogs, but it has been reported.
Signs And Symptoms: Common clinical signs include lethargy, anorexia, and mild pyrexia. Specific symptoms are the enlargement of the mandibular lymph nodes and atrophy of the temporalis muscle. The disease limits the ability of the dog to open its mouth, leading to anorexia and adipsia, which in turn leads to dehydration and emaciation.
Causes: Craniomandibular osteopathy is an inherited disease, and has been recognised as an autosomal recessive trait of the West Highland White Terrier. Canine distemper has also been indicated as a possible cause, as has E. coli infection, which could be why it is seen occasionally in large-breed dogs.