Dogs shake and tremble for all sorts of reasons — some completely harmless, others a sign of pain, poisoning, or illness. The key is learning to tell them apart. Here's how to think about a shaking dog. (General information, not a diagnosis.)
A shaking or trembling dog can be worrying, and the tricky part is that shaking is a symptom with a huge range of causes — from a chilly dog shivering to a serious medical emergency. Some shaking is perfectly normal; some demands an immediate vet visit. Knowing the difference, and especially recognizing the red flags, helps you respond appropriately. This guide walks through the common causes and when shaking is an emergency, while leaving the diagnosis to your veterinarian, who can examine your dog.
Harmless causes of shaking
Plenty of trembling is benign. Dogs shake when they're cold — just like us — especially small, short-haired, thin, or young dogs. They tremble with excitement or anticipation, like before a walk or a meal. They shake from fear, anxiety, or stress, such as during thunderstorms, fireworks, or vet visits. Some dogs, particularly small breeds like Chihuahuas, simply tremble more as a baseline. And a few learn that shaking gets attention. In these cases the dog is otherwise well, the trigger is obvious, and the shaking resolves when the cause passes.
Concerning causes of shaking
Other causes are more serious and need attention. Shaking can signal pain or discomfort anywhere in the body. It can accompany nausea (sometimes before vomiting). It can be a sign of illness or fever. It can reflect low blood sugar, especially in small breeds and puppies. It can point to neurological issues, certain muscle or metabolic conditions, kidney disease, or, in older dogs, problems like vestibular disease. And critically, generalized tremors or shaking can be a sign of poisoning — which is a true emergency.
Shaking vs. a seizure
It's important to distinguish ordinary shaking from a seizure, because a seizure is a medical emergency. With benign trembling, your dog is conscious, aware, and responsive to you, and can usually stop or be distracted. In a seizure, a dog typically loses awareness and can't respond, may collapse or fall over, may have rigid or paddling limbs, can lose bladder or bowel control, and is disoriented afterward. If your dog shows these signs, or has rhythmic, uncontrollable convulsions, treat it as an emergency and contact your vet immediately. When in doubt, a quick phone call helps you tell the difference.
When shaking is an emergency
Seek urgent veterinary care if shaking comes with any of these: suspected poisoning or eating something toxic; signs of a seizure; collapse, weakness, or inability to stand; repeated vomiting or diarrhea; difficulty breathing; a distended or painful belly; extreme lethargy or unresponsiveness; or signs of severe pain. Shaking that comes on suddenly and severely, or that's clearly different from your dog's normal behavior, is a reason to act quickly rather than wait. Puppies and small dogs with shaking plus weakness may have dangerously low blood sugar, which also needs prompt care.
When to see the vet (non-emergency)
For shaking that isn't an obvious emergency, see your vet if it's new, persistent, or unexplained; if it's not clearly tied to cold, excitement, or a passing fear; if it's becoming more frequent; or if it comes with milder signs of being unwell like reduced appetite or low energy. In older dogs, new tremors warrant a check, since age brings conditions that can cause them. It's always reasonable to call your vet to describe what you're seeing and let them advise.
What you can do
Your response depends on the likely cause. If your dog is cold, warm them up with a blanket or a cozy spot and see if the shaking stops. If it's anxiety, calmly remove or reduce the trigger and provide a safe, reassuring space — without over-fussing, which can reinforce the fear. But if the shaking is unexplained, persistent, severe, or comes with any worrying sign, or if you suspect a toxin, don't try to manage it at home — contact your vet. Never give human medications to a shaking dog without veterinary direction.
Helping an anxious, shaky dog
Anxiety is one of the most common everyday reasons dogs tremble, whether it’s thunderstorms, fireworks, car rides, or vet visits. The instinct to scoop up and soothe a frightened dog is natural, and quiet, calm reassurance is fine — but try not to make a dramatic fuss, which can inadvertently signal that there really is something to fear. Instead, create a safe retreat (a quiet room or covered crate the dog likes), use calming background noise, and stay relaxed yourself, since dogs read our energy. For dogs with severe or frequent anxiety — trembling, hiding, or panicking at every storm — talk to your vet, who can suggest behavioral strategies and, in some cases, anxiety treatments that genuinely help.
Shaking in older dogs
New trembling in a senior dog deserves a closer look, because age brings a few specific causes. Some older dogs develop tremors in the hind legs from muscle weakness or joint pain, and conditions like vestibular disease (which affects balance and can cause head tremors and unsteadiness) become more common with age. While some mild trembling in old age can be benign, it shouldn’t simply be written off as “just getting old,” since pain and treatable conditions are often involved. Our senior dog care guide covers monitoring an aging dog and knowing when changes warrant a vet visit.
Small breeds and the cold
If you own a Chihuahua, Italian Greyhound, or similar small, fine-coated dog, you’ve probably noticed they shiver readily, and often this is simply down to their size and thin coats. Small dogs lose body heat faster and have less insulation, so they genuinely feel cold more easily and shiver to warm up — a sweater or coat in cold weather, and warm bedding, can make a real difference. Some toy breeds also tremble from excitement or nervous energy as a baseline temperament trait. None of this means you should ignore shaking in a small dog: the same red flags apply, and small breeds are actually more prone to low blood sugar. But for a warm, happy, otherwise-well little dog, a degree of baseline trembling is often just part of who they are.
The bottom line
Dogs shake for reasons ranging from cold and excitement to anxiety, pain, illness, and poisoning, so context is everything. Harmless shaking has an obvious trigger and an otherwise well dog; concerning shaking is unexplained, persistent, or paired with other symptoms. Learn to tell shaking from a seizure, treat suspected poisoning or seizures as emergencies, and see your vet for any new or unexplained trembling. When in doubt, call. This article is general information, not a substitute for veterinary care.
Frequently asked questions
Why is my dog shaking or trembling?
Causes range from harmless to serious: cold, excitement, fear or anxiety, and some small breeds tremble as a baseline. More concerning causes include pain, nausea, illness or fever, low blood sugar, neurological issues, and poisoning. Harmless shaking has an obvious trigger and an otherwise well dog; unexplained or persistent shaking should be checked by a vet.
When is a shaking dog an emergency?
Seek urgent care if shaking comes with suspected poisoning, signs of a seizure, collapse or weakness, repeated vomiting, difficulty breathing, a painful belly, extreme lethargy, or severe pain. Sudden, severe shaking that's different from normal is a reason to act fast. Puppies and small dogs shaking with weakness may have low blood sugar.
How do I know if my dog is shaking or having a seizure?
With benign shaking, your dog is conscious, aware, and responsive and can usually be distracted. In a seizure, a dog typically loses awareness, can't respond, may collapse with rigid or paddling limbs, may lose bladder or bowel control, and is disoriented afterward. Seizure signs are an emergency — contact your vet immediately.
Can shaking be a sign my dog ate something poisonous?
Yes. A number of toxins — including chocolate, xylitol, certain human medications, some foods, and compounds like slug bait or moldy food — can cause trembling, twitching, or full-body tremors. If your dog is shaking and you suspect they ate something toxic, treat it as an emergency and contact your vet or an animal poison control service immediately.