Why does my dog chatter his teeth?

Could be the dog is scared or cold? If something odd is triggering the chattering perhaps a visit to the vet just to be certain nothing is wrong!

It is believed dogs who chatter their teeth are in a moment of pure over excitement.

If a dog has a dental issue like exposed roots, he or she will make a chattering noise if something hits it (like food). It's the exposed nerves reacting to stimulus.

Worst case scenario is that your dog is having focal motor seizures. These are mild in the respect they only target one area of the body at a time and eventually will pass but they could become more pronounced overtime and worth having a talk with your vet about it. Some cases will require an MRI or CT scan to make sure there are no lesions on the brain causing these seizures to happen. Taking a video of the occurrence so you can show the vet what was happening in the environment at the time and what the dog's body looked like is very helpful.

Hey there, he may be doing this for various reasons. Some reasons which shouldn't get you worried are: it may be due to him manifesting his emotions: happy, excited, elated, or he may be just finding a new scent that he's extremely excited about. On the other hand, a few reasons which should get you worried: dental problems, bigger diseases like epilepsy neurological diseases, fear, old age. Here's a more extensive explanation: https://goldenretrieverlove.com/why-do-dogs-chatter-their-teeth/ (https://goldenretrieverlove.com/why-d...)