The causes of a dog opening and closing mouth repeatedly may be various and you may be wondering what is causing this behavior and if it is something to be concerned about. Until dogs can talk, only assumptions can be made on what triggers certain behaviors in dogs. The best way to determine the source of the problem is by seeing the vet if the behavior persists. The causes of a dog opening and closing mouth and jaw repeatedly may vary, and because some causes can be concerning, it's always best to have the dog checked out by your veterinarian.
Food Stuck in the Mouth
If your dog opens and closes his mouth only after eating, chances are, there's nothing major to worry about. Dogs don't have tooth picks to remove food particles stuck between their teeth and their tongues are not as mobile as people's tongues are in removing food that's trapped along their gum lines.
Starchy kibble has a tendency to stick to a dog's teeth and dogs may dislike the sensation after eating. So what can they do to remove any food particles that are trapped along the gum line? Dogs resort to their own means to clean up their teeth from sticky substances by smacking their lips and the dog opening and closing mouth after eating.
In a dog opening and closing mouth after eating, dog owners may provide assistance by brushing the dog's teeth (if the dog allows it) or simply wrapping a finger with some gauze and removing the bothersome food. Caution is needed with dogs who do not like to have their mouth handled.
If your dog is persistently opening and closing his jaw after eating or if the behavior appears at other times other than after meal time, you may want to consult with your vet to determine the underlying cause of your dog's discomfort.
Presence of Foreign Substance
In some cases, when a dog repeatedly opens and closes his mouth there may be some foreign substance that's stuck somewhere in the dog's mouth that is causing the dog to try to remove it. Dogs are quick to notice when there is something in their mouth that shouldn't be there. Some dogs may get even frantic about it and act restless, pawing at their mouth and rubbing their faces in panic.
What can be stuck in the dog's mouth? It could be a piece of wood, plastic, a grass awn or even a bone shard that somehow managed to get stuck somewhere or in between the teeth that are all the way back in the mouth.
Sometimes a stick can manage to get stuck right across the roof of the dog's mouth. Finding the source of the problem can sometimes turn out being quite a challenge, explains veterinarian Dr. Bruce.
If your dog allows it, it may be helpful to take a look in his mouth for any foreign objects lodged somewhere. Caution is needed though as not all dogs like to have their mouth handled. If checking the dog's mouth is not feasible, it's best to have the dog see the vet for a better assessment.
Recording the behavior on tape and then showing it to the vet, may be extra helpful. Sometimes certain behaviors cannot be replicated at the vet's office and a video is worth 1,000 words trying to describe it.
Below is a video of how to check a dog's mouth.
Do Dogs Act Out of Spite? Here's What Science Says
Whether dogs act out of spite is an important question considering that spiteful behavior can put a big dent in your relationship with your dog. If your dog appears to pee, poop or destroy things out of spite, this is article is ultimately for you.
A Problem in the Mouth
Another possible cause for a dog opening and closing mouth repeatedly is a potential problem in the dog's mouth. For example, a dog may have a broken tooth and the sharp surface may feel odd causing the dog to open and close his mouth because it's perceived as a foreign item. A tooth that has dislodged and is loose may also "feel different" triggering this behavior. Even a cut somewhere in the mouth, some type of oral lesion or being stung be a bug may be some culprits.
Problems with the dog's mouth are not always readily noticed by dog owners. Even looking in the dog's mouth may not be helpful if the problem is a chipped tooth that is hard to notice. Certain areas of the dog's mouth may not be easy to view, and dogs may not be very collaborative.
A vet visit may be insightful in this case as the vet may take a closer look in the dog's mouth and perform a full oral evaluation (sedation may be needed at times), and if needed, the vet may request some dental x-rays if there are chances of a problem tooth.
A Sign of Nausea
If your dog is opening and closing mouth a whole lot and is also smacking his lips, consider that this can be a sign of nausea. Just as in in people, dogs produce more saliva when they start getting nauseous. This accumulation of saliva is not casual, it's actually meant to protect the dog's teeth enamel and mouth from the acidic nature of gastric acids found in a dog's vomit.
If your dog is smacking his lips and opening and closing the mouth because of nausea, the episode should subside either when the dog vomits or when the dog simply stares feeling better on his own. However, at times there may be an underlying cause that needs addressed.
Nausea in dogs may have various causes ranging from something that didn't agree with the dog's stomach, to ingestion of something toxic or even underlying systemic disorders. It's always a good idea to see the vet if the symptoms do not get better or persist.
A Symptom of Distemper
Distemper is a disease in dogs that is fortunately is not very common courtesy of dogs being vaccinated against this disease. The risks for this are therefore higher for dogs who are not vaccinated. Most dogs are vaccinated against distemper considering that it's a core vaccination recommended by vets. It's the "D" component of the DHLPP vaccination.
Canine distemper is a disease caused by a virus that attacks the dog's respiratory, nervous and digestive system. The disease is transmitted by other dogs but also wild animals such as foxes, wolves, coyotes, raccoons and skunks. Transmission occurs through airborne exposure just like a cold, through coughing and sneezing or sharing food and water bowls.
Affected dogs develop watery eyes, fever, nasal discharge, thickened foot pads, coughing, lethargy, loss of appetite and vomiting. When the nervous system is affected, it causes circling, muscle twitches, convulsions and jaw movements that are referred to as "chewing gum fits" as seen in the video below.
A Neurological Issue
If the dog is opening and closing the mouth repeatedly as if catching an imaginary fly, there are chances the behavior may be neurological, in particular caused by seizures.
When we think of seizures, we often think about the abrupt onset of severe muscle spasms, with the dog falling to the side and paddling the legs violently. These are known as gran mal seizures. Yet, there is another category of seizures that only involves a few body parts and these seizures are referred to as "partial seizures."
"Fly biting" is a behavior that has been associated with partial seizures because it only involves a few parts of the body. Also known as focal seizures, partial seizures are limited to only a part of the dog's brain which is why they are limited to only a few body parts. In some cases, biting the air and be triggered by an eye disorder, digestive issue or behavior disorder.
If your dog is opening and closing mouth repeatedly, consult with your vet for proper diagnosis. Below is a video of a dog with "fly biting seizures."