Have your dog examined by your veterinarian. Jaw chattering can be caused by several things. Diego's oral cavity needs to be thoroughly examined. Pain in the oral cavity can be from a broken tooth, abscessed tooth, or trauma to the oral cavity. Since Diego seems to exhibit the chattering when eating specifically pain would be my first rule out.
Facial pain or TMJ (temporomandibular joint) can cause jaw chattering. If pain is present when opening the mouth this may be the cause. Another less common disease is called masticatory myositis--this is an inflammation of the muscles that are involved in chewing--this usually is accompanied by a decrease in muscle mass.
Focal seizures can cause chewing movements. Usually seizures do not occur only when eating, are very intense, and accompanied by lots of drooling.
There are behavioral causes that can lead to jaw chattering--most commonly obsessive compulsive issues.
See your veterinarian to rule out the medical causes for jaw chattering and give you help treating if it is related to behavior.
Facial pain or TMJ (temporomandibular joint) can cause jaw chattering. If pain is present when opening the mouth this may be the cause. Another less common disease is called masticatory myositis--this is an inflammation of the muscles that are involved in chewing--this usually is accompanied by a decrease in muscle mass.
Focal seizures can cause chewing movements. Usually seizures do not occur only when eating, are very intense, and accompanied by lots of drooling.
There are behavioral causes that can lead to jaw chattering--most commonly obsessive compulsive issues.
See your veterinarian to rule out the medical causes for jaw chattering and give you help treating if it is related to behavior.