Common Causes and When to Worry
Dogs shake for many reasons — and most of them are completely harmless.
Your dog might be cold, excited to see you, or simply drying off after a bath. But shaking can also be your dog’s way of telling you something is wrong. The challenge is knowing which type of trembling deserves a calm response and which one deserves a phone call to your vet.
This guide breaks down the most common reasons why dogs shake, covers the health conditions that can cause persistent trembling, and tells you exactly when shaking stops being a minor quirk and starts being a medical concern.
Table of Contents
Why Do Dogs Shake? The Short Answer
Dog shaking can be voluntary or involuntary. Sometimes it’s a physical reflex — like shivering when cold. Other times it’s emotional, such as trembling during a thunderstorm. And in some cases, it’s a sign of pain, illness, or toxin exposure.
Most shaking resolves quickly and doesn’t affect your dog’s normal behavior. If your dog is eating, drinking, playing, and acting like themselves, an occasional tremble usually isn’t worth worrying about. The situation changes when shaking persists, comes on suddenly, or shows up alongside other symptoms.
Common Physical Causes of Dog Shaking
Being Cold or Wet
The simplest reason why dogs shake so much is temperature. When a dog gets cold or wet, the body triggers an involuntary shiver response to generate heat and reduce body heat loss. This is the same mechanism humans use.
Small breeds, older dogs, puppies, dogs with thin or short coats, and dogs that carry little body fat are more prone to cold-related shivering. If your dog starts shaking outdoors on a cool day and stops once they’re back inside and warm, the cold is almost certainly to blame.
After baths or swims, dogs shake to remove water from their fur. It’s impressively efficient — a dog can shed roughly 70% of the water from their coat in just a few seconds of full-body shaking.
Aging and Muscle Changes
Senior dogs commonly develop tremors, particularly in the hind legs. As dogs age, they lose muscle mass and their ability to regulate body temperature becomes less reliable. You might notice your older dog shaking lightly even indoors.
This is sometimes called “the Senior Shake” and can be associated with canine cognitive dysfunction syndrome (CDS) — a condition similar to dementia in humans. Age-related tremors don’t always require treatment, but they’re worth discussing with your vet, since shaking in older dogs can also signal arthritis or pain rather than normal aging.
Drying Off
A dog shaking off after getting wet is purely instinctual. There’s no cause for concern here. The full-body shake your dog does after a bath or a run through wet grass is a normal physical reflex.
Emotional and Behavioral Triggers
Fear and Anxiety
Shaking is one of the most recognizable signs of fear, stress, and anxiety in dogs. When a dog feels frightened or uneasy, their body releases adrenaline, priming them to either flee or react. Trembling is a physical byproduct of that adrenaline surge.
Common anxiety triggers include:
- Thunderstorms and fireworks
- Car rides or vet visits
- Strangers entering the home
- New environments or loud noises
- Separation from their owner
Stress-related shaking typically affects the whole body and stops once the trigger is removed. You can usually identify anxiety as the cause by watching for additional signs: pinned-back ears, tucked tail, wide or darting eyes, panting, lip-licking, and hiding.
If stress-related trembling is happening often, talk to your vet about behavior modification strategies or whether an anti-anxiety medication might help.
Excitement
Not all shaking points to something negative. Dogs frequently tremble with excitement — when you come home, when they hear the word “walk,” or when they’re waiting for a meal. A dog shaking with excitement typically has a loose, wiggly body, a wagging tail, and a relaxed face.
This type of shaking usually settles on its own once the moment of anticipation passes. Some dogs simply have bigger emotional reactions than others, and that’s not a problem.
Health-Related Causes of Dog Shaking
Pain and Discomfort
Pain is a common but easily missed reason why dogs shake all the time or more than usual. Dogs are naturally inclined to hide discomfort, so trembling might be one of the few visible signs that something hurts.
Pain-related shaking can be localized or spread across the whole body. Conditions that commonly cause it include:
- Arthritis or joint disease
- Back or spinal problems
- Ear infections (often causing head shaking rather than full-body trembling)
- Dental disease
- Urinary tract infections
- Stomach pain or severe nausea
If your dog is shaking and also whining, limping, reluctant to move or eat, or tensing when you touch a specific area, pain is a likely explanation. A vet visit is the right next step.
Nausea
Nausea can make dogs shake, especially if accompanied by excessive drooling, lip-smacking, yawning, and swallowing. Motion sickness, eating something that doesn’t agree with them, kidney disease, and liver problems can all trigger nausea-related trembling. If your dog also vomits after shaking, nausea is a strong candidate.
Low Blood Sugar (Hypoglycemia)
When blood sugar drops too low, the body responds with trembling, weakness, and in severe cases, seizures. Small-breed dogs and young puppies are most susceptible to hypoglycemia. The condition can worsen quickly, so if you suspect this is the cause, rubbing a small amount of honey or jam (not sugar-free) onto your dog’s gums and contacting your vet immediately is the recommended course of action.
Keeping your dog on a consistent feeding schedule with high-quality food is the best way to prevent blood sugar crashes.
Poisoning
Sudden, severe shaking is one of the red-flag signs of toxin ingestion. Several common household substances are toxic to dogs and can affect their nervous system, causing trembling, seizures, disorientation, vomiting, and diarrhea.
Substances known to cause shaking in dogs include:
- Chocolate
- Xylitol (found in sugar-free gum, candy, and some peanut butters)
- Grapes and raisins
- Garlic and onions
- Macadamia nuts
- Nicotine and cigarette products
- Certain medications
- Snail baits containing metaldehyde
- Toxic plants such as azalea, sago palm, and oleander
- Alcohol and marijuana
Poisoning is a medical emergency. If your dog is shaking suddenly and you have any reason to suspect they got into something they shouldn’t have, call your vet immediately or reach the Pet Poison Helpline at 855-764-7661 or the ASPCA Animal Poison Control Center at 888-426-4435. Don’t wait to see if symptoms improve on their own.
Seizures
Seizures and tremors can look similar, but there are important differences. During a seizure, your dog typically cannot respond to you, may lose bladder or bowel control, may paddle their legs, and may experience muscle stiffening or jerking. A dog that’s simply trembling from anxiety or cold remains aware and responsive.
Epilepsy is among the most common neurological conditions in dogs. Focal seizures — which affect only part of the body — can sometimes appear as localized trembling, which makes them harder to recognize.
Any first-time seizure or one lasting longer than two to three minutes requires immediate veterinary attention. Always notify your vet if you suspect your dog has had a seizure, even if they seem to recover quickly.
Medication Side Effects
Just as humans can react to medications, dogs can too. Shaking is a possible side effect depending on the type of medication, the dosage, how it’s administered, and the individual dog’s age and health status. If your dog recently started a new medication and shaking has followed, contact your vet to review whether an adjustment is needed.
Canine Distemper
Distemper is a serious viral illness most likely to affect unvaccinated puppies and adolescent dogs. In addition to trembling, it typically causes eye and nose discharge, fever, and coughing. Keeping your dog’s vaccinations up to date is the most effective way to prevent it.
Breed-Specific Traits: Shaker Syndrome
Some dogs shake not because of temperature, emotion, or illness, but because of a specific medical condition called Generalized Tremor Syndrome (GTS), also known as white dog shaker syndrome or corticosteroid-responsive tremor syndrome.
The condition was first documented in small, white dogs — breeds like the Maltese, West Highland White Terrier, Bichon Frise, and Poodle — but has since been identified in dogs of any size, breed, or coat color.
Signs and Typical Age of Onset
Dogs with GTS typically begin showing signs between one and two years of age. The tremors are rhythmic, repetitive, and involuntary. They can affect the whole body or just the head, and may range from mild to severe enough to interfere with eating and walking. Tremors tend to worsen with excitement or exercise and often improve or stop entirely when the dog is resting or asleep.
Cause and Diagnosis
The exact cause of shaker syndrome is still unknown, though it’s believed to be autoimmune in nature based on how well it responds to immune-suppressing medication. Diagnosis is typically one of exclusion — your vet will run blood tests and urinalysis to rule out other conditions. In some cases, a referral to a neurologist for advanced testing such as an MRI or cerebrospinal fluid (CSF) tap may be recommended.
Treatment and Prognosis
GTS is treated with prednisone, a corticosteroid. Most dogs see significant improvement within one to two weeks of starting treatment, and many achieve full resolution of symptoms. The prognosis is excellent — most dogs can be managed long-term with low doses of prednisone. If prednisone alone isn’t sufficient or causes problematic side effects, other immunosuppressive medications may be considered.
When to See a Vet About Dog Shaking
Occasional trembling that stops quickly and doesn’t affect your dog’s overall behavior is rarely a concern. But there are situations where shaking demands prompt veterinary attention.
Schedule a vet appointment if your dog:
- Shakes frequently or persistently without an obvious cause
- Has started shaking more than usual, especially in senior years
- Is shaking alongside changes in appetite, energy, or mobility
- Recently started a new medication and began trembling
Go to an emergency vet immediately if your dog:
- Is shaking and you suspect they ingested something toxic
- Has collapse, confusion, pale gums, or difficulty breathing alongside the shaking
- Appears to be having a seizure
- Is in obvious pain and cannot stand or move normally
- Shows unrelenting tremors that don’t ease up within a few minutes
When in doubt, call your vet. Describing the shaking — when it started, how long it lasts, whether it affects the whole body or just one area, and what other symptoms you’ve noticed — will help them assess the situation faster.
Frequently Asked Questions
Why is my dog shaking while sleeping?
Shaking during sleep is most often caused by REM sleep movement — in other words, your dog is dreaming. This is completely normal and typically involves twitching of the legs, paws, or face. It looks a little dramatic but doesn’t warrant concern unless the movements are very intense, don’t stop when you gently call your dog’s name, or occur alongside other neurological symptoms. In rare cases, sleep tremors can be seizure-related, so mention it to your vet if it happens regularly.
Why is my dog shaking after a bath?
This one is purely mechanical. Dogs shake off water instinctively — it’s an efficient drying method built into their biology. Post-bath shaking is normal and harmless. If you notice your dog also shivering (rather than just shaking off water), it may be because the bath was cool or the environment is cold. Drying them with a warm towel and keeping them in a warm room will stop it quickly.
Why does my dog shake and pant at the same time?
Shaking and panting together can indicate pain, heat, or stress. Dogs pant to regulate body temperature, so if they’re hot or overheated, you’ll often see both behaviors at once. Panting alongside shaking can also signal anxiety or an underlying health issue, including Cushing’s disease. If there’s no obvious cause like heat or recent exercise, it’s worth having your vet take a look.
Why is my dog always shaking — could it be a habit?
Some dogs do tremble more than others as a baseline, especially small breeds that are naturally more reactive to cold and stress. But if your dog always shakes, or if shaking is new and frequent, it shouldn’t be dismissed as a quirk. A vet check can rule out ongoing pain, anxiety disorders, or early signs of a neurological condition.
