Why Does Dog Keep Shallowing. Dental issues such as an abscess or tumor could be behind your dog constantly swallowing. If your dog is constantly swallowing, a dog may also be experiencing an anxiety attack or other mental health issues.

Several different dental issues might present itself by causing your dog to constantly swallow. If your dog is doing more swallowing than licking, esophagitis may prove the culprit. Dogs use their mouth to investigate their environment, often resulting in them swallowing foreign objects.