A dog that is opening and closing its mouth after eating probably has a piece of food stuck in its teeth or gums and is trying to work the piece out. The dog may require assistance but it is not likely. Owners should monitor this behavior to ensure it is not a symptom of something more serious.
Trapped Piece of Food
Some dogs eat voraciously, barely stopping to chew, while others pick at their food and chew slowly. Either way, a dog may get a piece of food stuck in its mouth or throat while eating. If the dog is unable to work the piece out by opening and closing its mouth, the owner needs to provide assistance by examining the dog's mouth. The owner must exercise caution in the examination to avoid being bit.
Removing Foreign Objects
Food trapped along the gum line is easily removed with a finger. Food trapped under the tongue presents more of a challenge. Dogs have small bones that support the tongue and some owners have mistaken them for chicken bones. Trying to pull out those bones can seriously injure the dog. If the dog is unable to work the piece of food out, the owner should seek veterinary assistance.
A dog may open and close its mouth after eating because it is having difficulty getting enough air, possibly due to choking on a piece of food. If the behavior persists, the owner may need to take emergency steps. The owner needs to help dislodge the piece of food either by suspending the dog in the air with the head down or lifting the rear legs to tilt the head down. Alternatively, administering a sharp strike with the palm of the hand between the shoulder blades, or using a modified Heimlich maneuver, may work.
Other Potential Causes
A dog that regularly opens and closes its mouth after eating with no obvious signs of food being stuck in the mouth or of choking, merits veterinary assistance. Potential problems may include: periodontal disease, gingivitis, abscesses or salivary cysts. If the dog shows other symptoms such as a swollen belly, the dog may have a serious medical condition called gastric dilatation-volvulus, commonly known as bloat. Bloat is a medical emergency requiring immediate veterinary assistance.