Ok. That is good.
Keep in mind that outwardly the teeth might look fine, but there might be a tooth that is damaged below the surface of the gum that we can't see. It can lead to constant licking
, as the dog tries to massage the sore tooth, and can also lead to occasional sneezing, or nasal discharge
as the sinuses are irritated by the tooth. This would lead to the licking.
Allergies can definitely cause slight irritation of the sinus and nasal passages. This might not always result in a runny nose, but can be irritating. Benedryl may be tried at 1 mg per pound every 12 hours.
The last possibility could be that there is a compulsive behavioral change. Some dogs start repetitive compulsive behaviors
for no real reason.
But truly this can be a serious problem and a sign of stress. What does a dog have to worry about? It's not that kind of stress. It just might be personality.
There are medications which can also help break the anxiety. In dogs I have used one called Clomicalm with very good success.http://www.clomicalm.novartis.us/
With any change in behavior like this, it is good to be sure there is no medical cause. It sounds like you have a good relationship with your Veterinarian. When was the last exam? If it has been longer than 6 months, I recommend checking again. Rule out any other issue that might be present - a blood test is needed.
Also, be sure at 8 years old that there isn't any other medical problem which can lead to behavior change. Dogs do weird things, in general. And sometimes they do weird things in response to pain. Try to find any sign of arthritis
or joint pain which might manifest as licking, or other behavioral compulsion.