Sometimes called “Westie jaw” or “Scottie jaw” by breeders, this is a disease most commonly seen in young West Highland white terriers, Scottish terriers and Cairn terriers that is thought to be inherited as an autosomal recessive trait.

The disease causes proliferation of the lower jaw bone, as well as the tympanic bullae (part of the inner ear bones), and can sometimes affect other bones of the head.

This causes abnormal enlargement of the bones when the bones are growing (i.

e.

when the dog is young), and can lead to some problems with chewing and swallowing, and difficulty opening the mouth.

Some affected puppies will have pain when opening their mouth.

This is usually a self-limiting disease, seen in dogs less than a year old.

Excessive bone growth slows and then stops at around a year of age, and in some cases may even recede somewhat.

Often treatment is symptomatic only, with soft foods and antiinflammatories/pain relief.