Why Your Dog’s Mouth Is Trembling — Causes of Jaw and Lip Shaking and How to Handle Them

Brain & CognitionQ&AMeongsiljang Veterinary Advisory Board

Here’s a summary of possible causes when your dog suddenly starts trembling its jaw or lips, along with guidelines to help you decide whether a vet visit is necessary.

What Kind of Symptom Is It When a Dog’s Mouth Trembles?

A concerned pet owner looking at their shivering dog

Trembling of a dog’s mouth is a neurological symptom in which the jaw, lips, and tongue shake rapidly and involuntarily. In most cases, it’s a physiological response to excitement or cold and stops quickly. However, if it lasts for several minutes or is accompanied by changes in consciousness or difficulty standing, it could be a sign of hypoglycemia, poisoning, or a neurological disorder. What really matters is when the trembling stops. If it subsides on its own within five minutes and the dog returns to normal behavior, monitoring the situation is sufficient. But if it recurs or is accompanied by other symptoms, immediate veterinary care is essential.

5 Common Causes of Mouth Trembling

Tremors in the mouth and jaw can be broadly categorized into physiological causes and those stemming from underlying medical conditions.

Cold and Stress: Shivering may occur as a response to maintain body temperature or during stressful situations. In fact, some tremors are known to worsen when a pet is excited or stressed.

Excitement and Anticipation: When pets are excited, such as right before receiving a treat or going for a walk, their lips may appear to tremble briefly.

Dental or Oral Pain: Oral issues like periodontal disease or periapical abscesses can cause pain, leading to frequent pawing or rubbing around the mouth, drooling, and apparent trembling of the mouth and jaw due to discomfort.

Hypoglycemia: In small-breed and young dogs, prolonged fasting can lead to jaw tremors accompanied by weakness and lethargy.

Neurological Disorders: Conditions such as idiopathic meningoencephalitis (meningoencephalitis of unknown origin) or steroid-responsive tremor syndrome (idiopathic tremor) may cause generalized or localized tremors.

Distinguishing Between Physiological Tremors and Disease-Related Tremors

Item	Physiological Tremor	Pathological Tremor
Duration	A few seconds to a few minutes	5 minutes or more, or recurring
Triggering situation	Cold, excitement, just before a treat	Occurs with no particular trigger
Other symptoms	None, active as usual	Lethargy, difficulty standing, decreased consciousness
Appetite	Normal	Decreased or refusing food
What to do	Keep warm and observe	Visit the vet immediately

If even one item falls under 'pathological,' a veterinary exam is needed.

Causes to Watch For Vary by Age and Body Size

Young small-breed dogs (under 5 kg): Hypoglycemia should be the first suspected cause. If your dog appears lethargic with trembling lips after fasting overnight or a long walk, apply honey or glucose to the gums and seek veterinary care immediately. Adult medium- and large-breed dogs: Tremors may result from dental pain or poisoning (e.g., human medications, xylitol, or chocolate). Senior dogs: The likelihood of idiopathic tremor syndrome, chronic kidney disease, or neurological conditions such as brain tumors or meningoencephalitis increases. If tremors become more frequent or gait becomes unsteady, prompt veterinary evaluation is essential.

A veterinarian examining a dog’s mouth and jaw in the clinic.

When to Go to the Vet Immediately

If any of the following apply, it may be an emergency: - Tremors lasting more than 5 minutes or occurring multiple times a day - Generalized seizures, decreased consciousness, or collapse occurring together - Staggering gait and falling to one side - Pale or bluish gums - Recent ingestion of human medications, xylitol, chocolate, or grapes - A young small-breed dog becoming lethargic and collapsing after fasting (hypoglycemic emergency) In these cases, even according to veterinary pharmacology textbooks, any delay in treatment can significantly worsen the prognosis.

What Tests Are Performed at the Vet?

Since jaw tremors can have multiple underlying causes, we diagnose them step by step.

Physical and neurological examination: We first assess cranial nerve function, gait, and reflexes.

Blood tests: We check blood glucose, liver and kidney function, and electrolytes to rule out hypoglycemia, hepatic encephalopathy, and kidney failure.

Oral examination and dental X-rays: We evaluate for periodontal disease, periapical abscesses, and tumors.

MRI and CT scans: If a neurological disorder is suspected, we use advanced imaging to examine the brain and spinal cord.

Cerebrospinal fluid analysis: This is performed if meningitis is suspected.

The order of these tests depends on the triggering situations and other symptoms you’ve observed.

A veterinarian conducting a neurological examination on a puppy

Emergency Steps You Can Take at Home Right Away

If your pet starts trembling, stay calm and check the following steps in order.

Check body temperature: If the paws and ears feel cold, wrap them in a blanket to help raise their body temperature.

Check fasting duration: If they haven’t eaten for more than 6 hours and are a young small-breed dog, apply a small amount of honey to their gums.

Check for ingestion of foreign substances: Immediately look for signs of ingestion of human medications, xylitol gum, or chocolate. If suspected, bring the packaging to the vet.

Record a video of the trembling: A 30-second to 1-minute clip can be very helpful for diagnosis.

Do not restrain forcefully: Since it can be difficult to distinguish from seizures, keep them calm in a quiet space.

Mouth Trembling Due to Dental Pain Is More Common Than You Think

Dental and oral issues often go unnoticed because they don’t always show obvious external signs. According to veterinary textbooks, most dogs with periodontal disease exhibit no clear outward symptoms until the condition progresses, at which point signs such as bad breath (halitosis), drooling, pain, frequent pawing at or scratching around the mouth, and in severe cases, tooth loss may appear. Therefore, if you notice tremors along with severe bad breath, chewing on only one side, drooling, or facial swelling, consider the possibility of oral pain and schedule a dental examination. However, periodontal disease cannot be accurately assessed through visual oral exams alone while the dog is conscious; the most precise diagnosis requires the use of a periodontal probe and dental X-rays under anesthesia. If general anesthesia is a concern, discuss the risks with your veterinarian to determine the appropriate timing for scaling and a thorough examination.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

Is it normal for my dog to twitch its mouth while sleeping?

Light trembling during sleep is a normal response commonly seen in the REM sleep stage. If your pet wakes up immediately and behaves normally when you rouse them, there’s no need to worry. However, if they don’t respond when called or if the tremors progress into full-body convulsions, it could be a seizure. In such cases, record a video and take your pet to the vet.

My dog only trembles when I give treats. Is this a problem?

It’s likely physiological trembling caused by excitement right before treats or walks. The shaking should stop as soon as your pet relaxes, and if there are no other symptoms, it’s within the normal range. However, if the trembling is so severe that your pet can’t eat treats, or if you notice wounds or bleeding in the mouth, consider the possibility of oral pain.

How can I tell if my pet is shivering because it’s cold or because it’s in pain?

If the trembling stops within 5 to 10 minutes after wrapping your pet in a blanket and raising the indoor temperature, it’s likely due to the cold. However, if the shaking persists despite warming up, or if it’s accompanied by lethargy, loss of appetite, or difficulty standing, it may be a sign of an underlying medical condition, and a veterinary visit is necessary.

Is it okay to leave my senior dog alone when they occasionally lift their chin?

Tremors in senior dogs can stem from various causes, including idiopathic tremor syndrome, dental pain, kidney disease, and neurological disorders. If the tremors become more frequent or your dog’s gait becomes unsteady, it’s advisable to have blood work and a neurological examination performed. Dismissing these signs as “just part of aging” and neglecting them can lead to missed opportunities for timely treatment.

Is it okay to keep anti-tremor medication at home?

We do not recommend administering medication on your own. The appropriate medication varies depending on the underlying cause, and human sedatives or muscle relaxants can be toxic to dogs. A veterinarian will determine the correct dosage and administration schedule based on your dog’s weight and the specific cause of the condition.