When a dog is panting heavily and shaking at the same time, it usually means something is stressing their body, whether that’s pain, fear, overheating, nausea, or something more serious like poisoning. These two symptoms together are your dog’s way of signaling distress, and the cause can range from a thunderstorm to a medical emergency. The key is reading the context: what else is happening, how suddenly it started, and whether your dog is acting normal otherwise.
Fear, Anxiety, and Excitement
The most common and least dangerous explanation is emotional. Dogs pant and tremble when they’re scared, stressed, or even thrilled. Thunderstorms, fireworks, vet visits, and separation anxiety are classic triggers. Some dogs shake just from the excitement of their owner walking through the door. If the panting and shaking started during an obvious emotional trigger and your dog is otherwise eating, drinking, and moving normally, this is likely the cause. The symptoms should resolve once the trigger passes.
Pain Is a Leading Cause
Dogs can’t tell you they’re hurting, so their bodies do it for them. Panting and trembling together are two of the most recognizable physical signs of pain in dogs. Other clues include tight or twitching muscles, an arched back, holding the head below the shoulders, excessive licking, reluctance to be touched, whimpering, and restlessness. You might also notice mobility changes like limping, walking slower than usual, or refusing to jump or climb stairs.
Arthritis is one of the more common pain sources, especially in older dogs whose hind legs may tremble from a combination of discomfort and muscle weakness. But acute injuries, abdominal pain, dental problems, and ear infections can all produce the same panting-and-shaking pattern. If your dog’s symptoms came on suddenly and you can’t identify an emotional trigger, pain should be high on your list of suspects.
Overheating and Heatstroke
Panting is how dogs cool themselves, so heavy panting in warm conditions is expected to a point. It becomes dangerous when it progresses to distressed or noisy breathing. Heatstroke is a life-threatening condition where the body temperature climbs high enough to damage organs. A dog’s normal internal temperature sits between 100.0°F and 102.8°F. Beyond that range, things can escalate quickly.
If your dog has been in heat or direct sun and is panting hard, move them into air conditioning and offer water. You can wet them with cool (not ice-cold) water and place them in front of a fan. For double-coated breeds like Huskies, Pomeranians, or Great Pyrenees, make sure the water reaches the skin. Ice-cold water can actually backfire by reducing blood flow to the skin or causing shivering, which generates more heat. If the heavy panting continues alongside drooling, vomiting, bloody diarrhea, weakness, confusion, or collapse, you’re looking at a heatstroke emergency that needs a vet immediately.
Poisoning and Toxic Ingestion
Tremors and panting can be your first warning that a dog has eaten something toxic. Chocolate, xylitol (a sweetener found in sugar-free gum and some peanut butters), and cigarettes are well-known culprits. Less obvious are moldy foods: dogs that get into compost bins, old walnuts, spoiled dairy, or forgotten pasta can ingest mold toxins that cause severe muscle tremors, vomiting, drooling, rapid heart rate, and seizures. Snail baits containing metaldehyde are another serious risk.
Poisoning symptoms often come on fast. If your dog was recently unsupervised and could have accessed trash, compost, a purse with gum in it, or anything else questionable, treat the situation as urgent. Don’t wait for symptoms to worsen.
Nausea and Stomach Problems
A nauseated dog will often pant and shake before actually vomiting. You might notice lip smacking, excessive swallowing or drooling, yawning, hiding, or general listlessness. Nausea can come from something as minor as eating too fast or as serious as pancreatitis or a gastrointestinal obstruction. If your dog vomits once and then returns to normal, it’s probably not an emergency. Repeated vomiting, especially with blood, is a different story.
Cushing’s Disease and Hormonal Problems
Cushing’s disease causes the body to produce too much cortisol, the stress hormone. It’s one of the more common hormonal conditions in dogs and produces chronic, persistent panting that doesn’t match the dog’s activity level or environment. About 80% to 85% of cases are caused by a small tumor on the pituitary gland that overstimulates the adrenal glands. The remaining cases involve a tumor on the adrenal glands themselves. Other signs include increased thirst, frequent urination, a pot-bellied appearance, and hair loss. Cushing’s develops gradually, so if your dog has been panting more over weeks or months rather than hours, bring it up with your vet.
Low Blood Sugar and Mineral Imbalances
When blood sugar drops too low, dogs can shake, tremble, or even have seizures. Small breeds and puppies are most vulnerable. Feeding regular meals usually prevents this, but underlying conditions like liver disease can make it chronic.
Low calcium levels are another metabolic trigger. This is most commonly seen in nursing mothers (a condition called eclampsia), but it can also result from kidney failure, pancreatitis, or certain toxins like antifreeze. Symptoms range from subtle nervousness and facial twitching to full-body muscle spasms and seizures. Exercise and excitement can make it worse. Both low blood sugar and calcium imbalances are treatable but need veterinary diagnosis.
Seizure Disorders and Neurological Causes
Sometimes what looks like shaking is actually a seizure or the aftermath of one. During a seizure, a dog may collapse, stiffen, jerk, twitch, drool heavily, or lose consciousness. Afterward, they may pant heavily, seem disoriented, and tremble for minutes to hours. Epilepsy is the most common neurological cause. A less well-known condition called generalized tremor syndrome (sometimes called white shaker dog syndrome) causes full-body tremors that typically appear between 9 months and 2 years of age. It responds well to treatment despite the alarming appearance.
When It’s an Emergency
Panting and shaking on their own don’t always mean a crisis, but certain accompanying signs do. Get to a vet immediately if you notice any of these:
- Breathing changes: gasping, wheezing, or gums that look blue, grey, white, or purple instead of pink
- Repeated vomiting or diarrhea, especially with blood
- Unresponsiveness: your dog won’t react to your voice or seems disoriented
- Seizures: uncontrollable shaking with drooling or loss of consciousness
- Abdominal swelling or bloating, particularly with retching, pale gums, or weakness
- Sudden paralysis or extreme weakness, especially in the hind legs
- Known or suspected poisoning
A dog’s normal resting respiratory rate is 10 to 30 breaths per minute. If you count your dog’s breaths while they’re resting and the number is consistently well above 30, that’s another objective sign that something is off. For heart rate, small dogs normally run 100 to 160 beats per minute and medium dogs 60 to 100. A significantly elevated rate at rest, combined with panting and shaking, points toward pain, fever, or cardiovascular stress.
How to Help at Home
Start by assessing the environment. Is it hot? Is there a storm? Did your dog just eat something unusual? Could they have gotten into the trash? Answering these questions narrows the possibilities quickly. If the room is warm, cool your dog down with water and air conditioning. If the trigger is clearly emotional, move them to a quiet space and stay calm yourself, since anxious owners tend to amplify a dog’s stress.
Watch the clock. Panting and shaking from fear or excitement typically resolve within 30 minutes of the trigger ending. Symptoms that persist for hours, worsen over time, or appear alongside vomiting, lethargy, or changes in gum color warrant a call to your vet. If your dog is a senior and you’ve noticed a gradual increase in panting or trembling over weeks, that pattern suggests a chronic condition like arthritis, Cushing’s disease, or organ dysfunction rather than a one-time event.