When your dog is sick that is vomiting, has diarrhea, and starts shaking, it’s natural to feel worried. These symptoms can appear suddenly and may signal anything from digestive upset to something more serious affecting the nervous or metabolic systems.
We outline the common causes of vomiting, diarrhea and shaking in dogs, what you can do at home, and when to seek veterinary help.
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Dog Sick Diarrhea and Shaking — Why It Happens
A dog vomiting, having diarrhea, and shaking is often experiencing internal distress — usually due to illness, pain, infection, or toxin exposure. Digestive issues such as food poisoning or viral infections can lead to diarrhea, while shaking may stem from discomfort, nausea, or fever.
Sometimes, the trembling is a response to dehydration, low blood sugar, or anxiety caused by the sickness itself.
When these symptoms occur together, it often means your dog’s body is under significant stress.
Dog Sick Diarrhea and Shaking: Common Causes
1. Gastroenteritis (Stomach Inflammation)
Gastroenteritis is one of the most common causes of sudden vomiting, diarrhea, and shaking in dogs.
This condition occurs when the stomach and intestines become inflamed — often from eating spoiled food, sudden diet changes, or bacterial infection.
The inflammation triggers fluid loss through diarrhea, while the shaking can result from pain, dehydration, or body temperature changes.
If your dog’s diarrhea is watery, foul-smelling, or contains mucus, and they’re trembling or lethargic, veterinary care is needed to prevent dehydration and restore gut balance.
Read more: Dog Sick Diarrhea and Vomiting (Why it happens and what to do)
2. Food Poisoning or Toxin Ingestion
When a dog ingests something toxic — such as chocolate, grapes, xylitol, certain plants, or cleaning products — the body reacts violently.
Diarrhea and vomiting occur as the system tries to purge the toxin, while shaking can result from nausea, internal pain, or the toxin’s effects on the nervous system.
Some poisons (like xylitol or caffeine) can cause tremors, seizures, and dangerously low blood sugar within hours. If you suspect your dog ate something toxic, call your vet or an emergency clinic immediately. Time is critical in these cases.
3. Infection (Viral or Bacterial)
Viral infections such as parvovirus, distemper, or coronavirus often begin with diarrhea and vomiting, quickly followed by fever, shaking, and weakness.
These infections attack the gastrointestinal tract and immune system, leading to inflammation, dehydration, and sometimes neurological signs. Puppies and unvaccinated dogs are especially at risk.
A sick dog with diarrhea, shaking, and lethargy should always be seen by a vet, as viral infections can escalate rapidly and be fatal without prompt treatment.
4. Low Blood Sugar (Hypoglycemia)
Shaking paired with diarrhea can also indicate hypoglycemia, especially in small or toy breeds.
When blood sugar drops too low — often from skipping meals, stress, or illness — dogs can tremble, become weak, and even collapse. Diarrhea may worsen the issue by reducing nutrient absorption.
Offer a small meal or a lick of honey on the gums if your dog is alert, but seek veterinary care immediately if symptoms persist, as severe hypoglycemia can lead to seizures or coma.
5. Pain or Fever
Dogs in pain or with fever often shake as a physiological response. If the illness causing diarrhea also triggers abdominal pain or infection, the trembling can worsen.
Fever raises the dog’s body temperature, while shivering helps regulate it. Signs like panting, restlessness, or whining suggest your dog is uncomfortable.
Persistent pain or shaking accompanied by diarrhea usually signals an underlying infection, pancreatitis, or another systemic problem requiring medical attention.
6. Stress and Anxiety
Stress can cause both digestive upset and trembling.
Dogs are sensitive to environmental or emotional stressors such as boarding, thunderstorms, or loud noises. Stress triggers the release of adrenaline and cortisol, which can alter gut motility and lead to diarrhea.
If your dog’s diarrhea appears after a stressful event and they’re trembling but otherwise alert, it may be a mild stress reaction. Offer comfort, a quiet space, and hydration — symptoms usually resolve within a day.
7. Metabolic or Organ Disorders
Liver disease, kidney failure, or Addison’s disease can all cause chronic diarrhea, weakness, and trembling.
These disorders disrupt normal metabolism and electrolyte balance, making dogs feel sick, shaky, and dehydrated. You might also notice increased thirst, weight loss, or changes in appetite.
Blood tests and imaging are needed to confirm the diagnosis and start appropriate treatment.
Read more: Dog Sick Diarrhea and Lethargy (Why it happens)
What to Do If Your Dog Is Sick, Has Diarrhea and Shaking
When your dog develops vomiting, diarrhea and shaking, stay calm but observant — the combination often means their system is under strain.
First, check your dog’s hydration. Gently lift the skin over their shoulders; if it doesn’t snap back quickly, dehydration may be setting in. Offer small amounts of water frequently, or an electrolyte solution made for dogs.
Withhold solid food for 8–12 hours to rest the digestive tract, then reintroduce a bland diet such as boiled chicken and plain rice in small, frequent meals.
If your dog seems cold or shivering, keep them warm with a blanket, but don’t overheat them. Shaking may also indicate fever or pain, so monitor their temperature if possible — normal is around 101–102.5°F (38–39°C).
Avoid giving over-the-counter medications unless directed by your vet, as human drugs can worsen vomiting or harm your dog’s organs.
If your dog improves after rest and bland meals, gradually return to their regular diet over a few days. But if they refuse food, continue shaking, or have bloody diarrhea, it’s time to call your veterinarian.
When to Call or Visit Your Vet
Contact your vet right away if your dog:
Shakes continuously or seems unable to stand
Has bloody, black, or watery diarrhea
Is vomiting repeatedly or cannot keep water down
Shows signs of dehydration or sunken eyes
Acts weak, confused, or unresponsive
Has a distended or painful abdomen
These symptoms may signal parvovirus, poisoning, pancreatitis, or organ dysfunction, which require immediate professional treatment.
Even if your dog appears to stabilize, lingering diarrhea and tremors can still point to deeper health issues that need testing. A stool sample, bloodwork, and possibly imaging will help your vet pinpoint the exact cause.
Read more: Dog Sick Diarrhea (Common causes explained)
Key Takeaway
When your dog is sick, has diarrhea, and starts shaking, it’s their body’s way of signaling distress. It might be a mild stomach upset or something far more serious — but in every case, close observation and early action are key.
Offer hydration, rest, and a gentle diet for mild cases, but don’t delay veterinary help if your dog’s symptoms persist or worsen.
Prompt care can mean the difference between a simple recovery and a serious medical emergency — helping your dog feel safe, strong, and back to their happy self again.