Pugs shake for many reasons, and most of them are harmless. Cold temperatures, excitement, and anxiety are the most common triggers. But because pugs are prone to certain breed-specific conditions affecting the spine and brain, shaking that comes on suddenly, lasts more than a few minutes, or pairs with other symptoms is worth taking seriously.
Cold, Excitement, and Anxiety
Pugs are a small breed with a short, single-layer coat, which makes them lose body heat faster than larger or double-coated dogs. If your home is cool, the air conditioning is running, or you’ve just come in from a chilly walk, simple cold is the most likely explanation. Brief trembling after a bath or getting caught in rain is also normal.
Excitement is another everyday cause. Many pugs shake or tremble when they greet you at the door, anticipate a meal, or see their leash come out. This kind of shaking is short-lived and stops once the dog settles. Anxiety works the same way but in reverse: thunderstorms, fireworks, car rides, vet visits, or unfamiliar people can trigger trembling that lasts as long as the stressor does.
If anxiety-related shaking is a recurring problem, building predictability into your pug’s daily life helps more than most people expect. Researchers at Cornell University’s veterinary college emphasize that dogs cope better when they can anticipate what comes next. Feeding, walking, and resting at consistent times gives your pug a sense of control. Crate training is especially useful: a dog that already associates its crate with calm rest periods will retreat there willingly during stressful events like fireworks. You can also teach a simple routine, like sitting before being petted or offering a paw after a walk, so your pug learns that specific behaviors lead to specific outcomes. That predictability itself is calming.
Low Blood Sugar
Pugs, like other small breeds, are more susceptible to drops in blood sugar. Hypoglycemia in dogs is defined as blood glucose falling below 60 mg/dL. When this happens, the body releases a burst of stress hormones to try to push glucose back up, and one visible result is shaking or trembling. You may also notice weakness, wobbliness, reduced energy, or your pug seeming “off.”
Puppies and senior pugs are most vulnerable, especially if they’ve skipped a meal, exercised heavily, or are on certain medications. If the shaking stops after your pug eats and perks up quickly, a missed meal or too-long gap between feedings may be the culprit. Persistent or repeated episodes need veterinary bloodwork to rule out underlying causes like Addison’s disease, a condition where the adrenal glands don’t produce enough cortisol to maintain normal blood sugar.
Muscle Fatigue in Older Pugs
If your pug is getting up in years and you notice their legs trembling after standing for a while, muscle fatigue is a likely cause. As dogs age, they lose muscle mass, and weakened muscles shake when they’re asked to support the body longer than they comfortably can. The trembling typically starts in the hind legs and stops once your pug lies down and rests.
Arthritis compounds this problem. Painful joints make a dog shift weight awkwardly, which overloads certain muscles and accelerates fatigue. If your senior pug’s legs shake during walks that used to be easy, or they hesitate before jumping onto furniture, joint pain and muscle loss are working together. Keeping your pug at a healthy weight reduces the load on aging joints and muscles significantly.
Hemivertebrae and Spinal Problems
Pugs are bred for their curly, corkscrew tails, but that same trait comes with a cost. The screw tail is actually a spinal deformity, and the abnormally shaped vertebrae that create it can appear elsewhere in the spine too. These wedge-shaped bones, called hemivertebrae, don’t stack neatly. They can compress the spinal cord or pinch the nerves branching off it.
The result is hind-leg wobbliness, trembling, pain, and in more severe cases, loss of hind-leg function or incontinence. Signs can appear gradually or come on quickly, and they sometimes worsen over time. If your pug’s shaking is concentrated in the back legs and comes with an unsteady gait, reluctance to jump, a hunched posture, or signs of back pain, spinal compression is a real possibility. Diagnosis typically involves imaging of the spine.
Pug Dog Encephalitis
Pug Dog Encephalitis (PDE) is an inflammatory brain disease that occurs almost exclusively in pugs. It causes seizures, disorientation, circling, behavioral changes, and tremors. It tends to strike young to middle-aged pugs, and it progresses over weeks to months.
The disease has a genetic component. Testing by UC Davis found that about 40% of pugs carry the associated risk gene variant, with roughly 11% carrying two copies. A European study of nearly 6,000 pugs found the risk variant at a frequency of about 26%. Carrying the gene doesn’t guarantee the disease will develop, but it does increase susceptibility. PDE is serious and often fatal, so any combination of seizures, head tilting, vision changes, or personality shifts alongside shaking warrants urgent veterinary evaluation.
Poisoning and Toxin Exposure
Sudden, unexplained shaking is one of the hallmark signs of poisoning in dogs. Chocolate, grapes, certain medications, and household chemicals are well-known dangers, but one of the most common toxins is xylitol, a sugar substitute found in sugar-free gum, mints, some peanut butters, toothpaste, chewable vitamins, and even certain baked goods. In dogs, xylitol triggers a massive insulin release that crashes blood sugar within 10 to 60 minutes. Symptoms include weakness, staggering, trembling, collapse, and seizures. In some cases, more severe effects like liver damage can take 12 to 24 hours to appear.
If your pug is shaking and you notice vomiting, drooling, disorientation, diarrhea, or weakness alongside it, think about what they may have gotten into. Time matters with toxin exposure, and faster treatment leads to better outcomes.
Fever
Dogs shiver when they have a fever for the same reason people do: the body is trying to generate heat to reach a new, higher temperature set point. A normal dog’s body temperature runs between 101 and 102.5°F. Anything above that range, especially above 103°F, signals fever. Infections, immune reactions, and inflammation can all cause it. You can’t reliably detect a fever by touching your pug’s ears or nose. A rectal thermometer designed for pets is the only accurate at-home method.
When Shaking Signals an Emergency
Not all shaking needs a vet visit, but certain combinations of symptoms do. Shaking paired with vomiting, diarrhea, limping, or lethargy suggests something beyond simple cold or excitement. Collapse, stiffening, jerking movements, loss of consciousness, paddling legs, or foaming at the mouth point to a seizure rather than ordinary trembling.
Signs of distemper, a serious viral infection, include trembling alongside eye and nose discharge, fever, loss of appetite, head tilting, walking in circles, and lack of energy. Distemper is most common in unvaccinated dogs.
As a general rule: if your pug starts shaking suddenly with no obvious trigger like cold weather or the doorbell ringing, if the shaking lasts longer than you’d expect, or if any other symptom accompanies it, get a veterinary assessment. Bring notes on when it started, how long it lasted, and anything your pug may have eaten or been exposed to.