Why Is My Dog Shaking or Trembling? A Burlington Vet Explains

The call usually starts the same way. “He’s just standing in the kitchen, shaking, and I don’t know why.”

Some mornings it’s a small dog trembling by the back door after a cold, wet walk along Brant Street. Other times it’s an owner watching their dog shiver on the couch, unsure whether to wait it out or drive in.

Shaking is one of the questions our team hears most. It can mean almost nothing or something urgent, and the hard part is that both can look surprisingly alike from across the room.

Dogs shake for everyday reasons like cold, excitement, and nervousness, but trembling can also signal something serious. In a veterinary case series of 198 dogs with generalized tremors, poisoning was the single most common cause (46%), followed by idiopathic generalized tremor syndrome, according to a study published in JAVMA. New or sudden shaking is worth a call.

If this is happening right now and your dog is shaking along with vomiting, collapse, disorientation, or a suspected toxin, treat it as an emergency. Call us at (905) 336-4002, reach the Pet Poison Helpline at 855-764-7661, or find the nearest open hospital through our after-hours care page.

Should I be worried if my dog is trembling?

Sometimes yes, sometimes no. Trembling on its own doesn’t tell you much until you factor in how suddenly it started, whether your dog is acting normal, and what they might have eaten. According to a study in JAVMA, poisoning was the most common cause of generalized tremors in a series of 198 dogs, so a sudden case earns a call.

That statistic isn’t meant to scare you. In the same JAVMA series, low blood sugar and other conditions made up smaller shares, and most shaking we see in Burlington turns out to be cold, nerves, or excitement that settles once the dog does.

A simple rule of thumb helps. A dog who is bright, eating, walking normally, and stops shaking once they relax is lower on the worry scale.

A dog trembling plus vomiting, wobbly, hiding, or refusing food belongs at the top.

Why is my dog shaking but acting normal?

A dog who trembles but is otherwise bright, eating, and moving well is usually reacting to something ordinary: cold, excitement, or a bit of nervousness. These everyday triggers pass once your dog warms up or calms down. When shaking arrives with other symptoms, or won’t stop, that’s when it moves from normal to worth checking.

Think about the context. A wet dog on a raw November afternoon, a nervous pup before a walk, an excited dog watching you reach for the leash: these are the everyday triggers owners ask us about, and they settle on their own.

What we watch for is a change in the pattern. Shaking that’s new for your dog, that keeps going after they’ve warmed up and relaxed, or that shows up alongside any other sign is worth a phone call, so trust your read of your dog’s baseline if the trembling feels different.

Can shaking be a sign my dog was poisoned or ate something toxic?

Yes, and it’s a leading reason vets see tremors. According to the Merck Veterinary Manual and the Pet Poison Helpline, toxins from mouldy food, chocolate, and the sweetener xylitol can all cause shaking, and eating mould from compost or food waste can trigger tremorgenic neuromycotoxicosis within 1 to 2 hours. If you suspect a poison, call right away.

Burlington’s green bins, backyard compost, and a forgotten bag of pantry food are everyday hazards. According to the Merck Veterinary Manual, mould that grows in food, feed, or compost can cause a tremor syndrome, with signs including vomiting, drooling, muscle tremors, incoordination, overheating, and seizures.

The Pet Poison Helpline adds that these mycotoxins turn up in garbage, compost, and old bread, cheese, or nuts. It notes signs can appear quickly and last 24 to 48 hours.

Food off the counter is just as risky. The Merck Veterinary Manual reports that chocolate toxicosis can progress from vomiting and restlessness to rigidity, tremors, and seizures, with severity dose-dependent: mild signs around 20 mg/kg of theobromine and seizures at 60 mg/kg or higher.

Xylitol is the other counter hazard. According to the Pet Poison Helpline, this sweetener in sugar-free gum, candy, and some peanut butters triggers a rapid insulin release that drops blood sugar, with warning signs including weakness, incoordination, body tremors, and seizures.

If your dog is shaking and might have gotten into any of these, call us or the Pet Poison Helpline right away, and note what they ate.

Is my dog shaking because he’s cold?

Often, yes. Cold, wet walks along Lake Ontario make plenty of Burlington dogs shiver, especially short-coated or small breeds. But shivering isn’t a reliable sign of true hypothermia. According to the Merck Veterinary Manual, a genuinely cold dog more often turns weak or disoriented, breathes shallowly, or has a slow pulse than simply shivers.

A quick shiver that stops once your dog is dry and warm is usually just that. Our winters run cold and windy off the lake, and a soaked coat loses heat fast, so the quieter warning signs matter more than the shivers.

Ontario winters add one more wrinkle. The Merck Veterinary Manual warns that prolonged cold exposure is dangerous and that frostbite is more likely in wet or windy conditions, which describes a lot of Halton days from December through March.

Keep outdoor time short in freezing, damp weather. Dry your dog off at the door.

Why is my small dog or white dog shaking so much?

Small, light-coated dogs get flagged for a condition owners often hear about: “little white shaker syndrome.” According to peer-reviewed veterinary literature, idiopathic generalized tremor syndrome causes acute, full-body tremors, is believed to be immune-mediated, and usually responds well to corticosteroid treatment. It needs a vet’s diagnosis, not a guess at home.

The nickname is a little misleading. It points to small, light-coated dogs as the classic patients, but the syndrome shows up in dogs of many colours and sizes.

Peer-reviewed research describes this condition, also called steroid-responsive tremors, as a sudden onset of whole-body shaking that improves with corticosteroids.

Because the tremors come on fast and involve the whole body, this isn’t something to wait out. A proper exam and workup separates it from the toxin and low-blood-sugar causes that look similar at first.

Is my dog shaking, or is it a seizure? How do I tell the difference?

Telling a tremor from a seizure across the room is genuinely hard, and it isn’t something we sort out over the phone. According to Cornell’s Riney Canine Health Center, idiopathic epilepsy is a common cause of recurrent seizures in dogs, usually starting between 6 months and 6 years of age. If you’re not sure which one you’re seeing, film a short video and call us.

The causes overlap, which is exactly why we don’t try to diagnose this from a description. According to Cornell’s Riney Canine Health Center, idiopathic epilepsy runs higher in several purebred lines, and, as covered above, low blood sugar or toxins can both progress to seizures.

The Merck Veterinary Manual adds that canine distemper can cause muscle twitching, rhythmic jerking called myoclonus, “chewing-gum” jaw movements, and seizures. That’s one more reason we keep core vaccinations current.

The single most useful thing you can do is record a short video. What looks like a seizure to a worried owner and what a vet needs to see are often different details.

When should I take my shaking dog to the vet or emergency clinic?

Call the same day for any new, sudden, or unexplained shaking, and treat it as an emergency if trembling comes with vomiting, collapse, disorientation, non-stop tremors, or a suspected toxin. Shaking after a bite or wildlife encounter is also urgent. According to Halton Region, animal bites and possible rabies exposures should be reported to Public Health by calling 311.

Some signs don’t leave room to wait. Shaking plus repeated vomiting, a wobbly or collapsing dog, tremors that won’t stop, known access to chocolate, xylitol, or mould, or trembling that tips into a seizure all mean call us now.

There’s a local angle worth knowing. According to Halton Region, all animal bites, scratches, and possible rabies exposures should be reported by calling 311, and Burlington’s animal control is the Burlington Animal Shelter at 905-335-7777.

Shaking after a bite or a bat encounter deserves fast attention.

For red-flag cases outside our hours, our after-hours and critical care resources point you to the nearest open emergency hospital. When in doubt, a quick call to our team on Brant Street beats guessing.

This article is educational and isn’t veterinary advice or a substitute for an exam. If you’re worried about your pet right now, call us at (905) 336-4002 or your nearest emergency veterinary hospital.

If your dog’s shaking has you second-guessing, you don’t have to sort it out alone. Our team is glad to talk it through and see your dog if needed.

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Frequently asked questions

Why is my old dog’s back legs shaking or trembling?

Trembling in the back legs is one of the questions our team hears most from Burlington families with older dogs. Because it can come from several different sources, this is a symptom we prefer to see rather than diagnose over the phone. An exam lets us check strength, comfort, and coordination and point you toward the right next step.

Can anxiety or fear make my dog shake?

Nerves and fear are among the everyday triggers owners ask us about, and Burlington has predictable ones: Canada Day fireworks, summer thunderstorms, and the vacuum cleaner. Fear-related trembling usually eases once the trigger passes and your dog feels safe. If it’s frequent, severe, or paired with other signs, it’s worth a conversation with our team.

Why is my dog shaking and not eating all of a sudden?

Shaking combined with a refusal to eat is a pairing we take seriously, because two symptoms together raise the odds that something is genuinely wrong. This is not a wait-and-see situation. Call us the same day so we can help you decide whether your dog needs to be seen right away.

Can low blood sugar make my dog shake?

Yes. According to the Merck Veterinary Manual, early signs of low blood sugar in dogs include weakness, muscle twitching, lack of coordination, and confusion, and severe hypoglycemia is a medical emergency that can cause seizures, collapse, and brain damage. If your dog is shaking and weak, call us or an emergency hospital promptly.

My dog ate something mouldy from the compost. What should I do?

Don’t wait for signs to build. According to the Merck Veterinary Manual, mould in food or compost can cause tremors, and the Pet Poison Helpline notes signs can appear quickly and last 24 to 48 hours. Call us at (905) 336-4002 or the Pet Poison Helpline at 855-764-7661, and bring what your dog ate if you can.

Is trembling after a bite or a bat encounter an emergency?

Treat it as urgent. According to Halton Region, all animal bites, scratches, and possible rabies exposures should be reported to Public Health by calling 311, with Burlington Animal Shelter reachable at 905-335-7777. Neurologic signs such as shaking after a wildlife or bite encounter warrant a prompt call to us and to Public Health.

Sources

Merck Veterinary Manual

1. Tremorgenic Neuromycotoxicosis in Dogs
2. Chocolate Toxicosis in Animals
3. Disorders of the Pancreas in Dogs (Dog Owners)
4. Canine Distemper Overview
5. What to Do in a Dog or Cat Emergency
6. Keeping Pets Safe During Cold Winter Months

Pet Poison Helpline

1. The Dangers of Mycotoxins in Dogs
2. Symptoms of Xylitol Poisoning in Dogs

Peer-reviewed research (NCBI/PMC)

1. Generalized Tremors in Dogs: 198 Cases (2003-2023), JAVMA
2. Canine Idiopathic Generalized Tremor Syndrome, Immune-Mediated?

Cornell University College of Veterinary Medicine

1. Idiopathic Epilepsy in Dogs, Riney Canine Health Center

Halton Region

1. Protecting Your Family and Pets Against Rabies