When a dog is vomiting, having diarrhea, shaking, and refusing to eat, it’s one of the most alarming combinations of symptoms a pet owner can face.
These issues together often signal that something more serious is happening internally, and it’s important to understand what may be going on and how quickly to respond.
This guide explains the most common causes of sudden vomiting, diarrhea, shaking, and loss of appetite in dogs, what you can do at home, and when it’s best to involve your veterinarian.
Dog Vomiting, Diarrhea, Shaking and Not Eating: Why It Happens
A dog showing vomiting, diarrhea, shaking, and refusing food is usually dealing with a significant medical issue that affects their digestive system, nervous system, or overall stability. These symptoms often appear when the body is trying to rid itself of toxins, reacting to severe inflammation, or struggling with pain or dehydration.
Gastroenteritis, infections, toxin ingestion, pancreatitis, and organ dysfunction can all lead to this distressing combination of signs.
The shaking typically signals discomfort, nausea, fever, or stress, while the loss of appetite happens because the dog’s body is too overwhelmed to focus on eating.
Dog Vomiting, Diarrhea, Shaking and Not Eating: Common Causes
Pancreatitis
Pancreatitis occurs when the pancreas becomes inflamed, usually triggered by eating fatty foods but sometimes happening without a clear cause. When the pancreas is irritated, digestive enzymes begin damaging internal tissues instead of assisting with digestion.
Dogs with pancreatitis often vomit repeatedly, develop watery or mucus-filled diarrhea, and shake from intense abdominal pain.
A dog suffering from pancreatitis usually avoids eating because food worsens discomfort. This condition can escalate quickly, and repeated vomiting can make dehydration and shaking much worse.
Pancreatitis is serious and sometimes life-threatening, especially when paired with multiple symptoms like these.
Related: Old Dog Shaking and Vomiting (Causes explained)
Gastroenteritis
Gastroenteritis—severe inflammation of the stomach and intestines—is one of the most common reasons a dog develops vomiting and diarrhea together.
When the digestive tract becomes irritated, fluid loss happens rapidly, which can lead to shaking from dehydration or discomfort.
Many dogs with gastroenteritis refuse food because eating worsens their nausea or abdominal pain.
Symptoms can escalate quickly, especially if the vomiting and diarrhea are continuous. Shaking may indicate worsening dehydration or increasing inflammation.
Even though some cases are mild, the presence of multiple symptoms at once suggests a more severe form that typically requires veterinary attention.
Toxin Ingestion
Ingesting toxins—such as spoiled food, household cleaners, human medications, toxic plants, or chemicals—can cause sudden and severe gastrointestinal distress.
When the body detects harmful substances, it attempts to expel them rapidly, resulting in vomiting and diarrhea.
Shaking often appears as the toxin affects the nervous system or as the dog becomes weak and distressed. Refusal to eat is a natural response when the body is under toxic stress.
Toxins can cause organ failure, seizures, internal bleeding, or shock, so this combination of symptoms must always be treated urgently.
Parvovirus
Parvovirus is a highly contagious and often deadly viral infection in dogs—especially puppies or unvaccinated adults.
Vomiting and profuse, foul-smelling diarrhea are hallmark signs. As dehydration progresses, shaking begins, and the dog becomes too weak or nauseated to eat.
Parvo destroys the lining of the intestines, leading to severe fluid loss and a high risk of bacterial infection entering the bloodstream.
Because of how aggressively this virus spreads and worsens, any dog showing multiple symptoms should be seen immediately, especially if they are young or not fully vaccinated.
Severe Dehydration
When vomiting and diarrhea occur together, dehydration can develop in a matter of hours.
Dehydration affects blood pressure, internal organs, and the dog’s ability to regulate their body temperature.
Shaking is a common sign that dehydration has progressed to a dangerous level. A dehydrated dog will feel weak, cold, and unable to eat because their systems are shutting down to conserve energy. Without immediate care, dehydration can cause organ failure or collapse.
Even mild dehydration can escalate quickly when symptoms are ongoing.
Intestinal Blockage
If a dog swallows something they shouldn’t—like a toy, bone, sock, or piece of fabric—the item can get stuck in the intestines.
Vomiting occurs because food and fluid cannot pass the obstruction. Diarrhea may happen when liquid around the blockage pushes through, creating a misleading sense that the gut is still functioning.
Shaking often signals pain or worsening distress, and a dog with an intestinal blockage almost always stops eating. This condition requires surgical intervention in most cases, and delays can be fatal.
Related: Dog suddenly not eating and vomiting (Here’s why)
What to Do If Your Dog Is Vomiting, Has Diarrhea, Is Shaking, and Not Eating
If your dog is showing this combination of symptoms, the first step is to evaluate how quickly the signs started and whether they seem to be worsening.
Because vomiting and diarrhea together can lead to rapid dehydration, you should avoid offering large amounts of water or food immediately, as this may trigger more vomiting. Instead, allow your dog to rest in a quiet, comfortable area while monitoring their breathing, shaking, and hydration.
You can check hydration by gently lifting the skin on the back of the neck. If it doesn’t snap back quickly, dehydration is already present. At home, you can offer small amounts of water or an electrolyte solution after vomiting stops for at least a couple of hours.
Do not give food until your dog can keep fluids down reliably. Avoid home remedies like over-the-counter medications, as many are unsafe for dogs and may worsen symptoms.
If your dog is trembling from pain, cold, or weakness, keep them warm with a soft blanket and minimize movement. Shaking combined with refusal to eat often means their body is under significant stress.
If the symptoms started after your dog may have eaten something unusual, note any possible toxins, foods, or objects they could have swallowed, as this information will help the vet diagnose the problem more quickly.
Most importantly, keep a close eye on frequency. Vomiting every hour, continuous diarrhea, or shaking that does not subside all indicate that home care may not be enough.
While mild stomach upset can improve with rest, this combination of symptoms is much more concerning and often requires professional treatment.
When to Call or Visit Your Vet
You should contact a veterinarian immediately if your dog continues vomiting or has diarrhea for more than a few hours, as dehydration can set in quickly. If the shaking worsens or your dog becomes too weak to stand, this is a sign of significant distress and should never be ignored.
Vomiting that contains blood, diarrhea that looks dark or tar-like, or shaking that appears to be caused by extreme pain are all urgent warning signs.
Puppies, senior dogs, and dogs with chronic conditions—such as diabetes or kidney disease—are at even higher risk of complications.
If you suspect toxin ingestion or if your dog has not kept any food or water down for 12 hours, emergency care is necessary.
Sudden weakness, pale gums, collapse, or a bloated abdomen require immediate veterinary attention, as these symptoms may indicate life-threatening issues such as internal bleeding, organ failure, bloat, or severe infection.
Read more: Dog Shaking and Vomiting (Why it happens)
Key Takeaway
Vomiting, diarrhea, shaking, and not eating together are never symptoms to ignore in a dog.
This combination often points to significant illness, ranging from severe gastrointestinal inflammation to toxins, dehydration, or life-threatening infections. Early action is crucial, and even if some cases begin mildly, they can escalate quickly.
Offering gentle support at home can help, but most dogs with these symptoms need veterinary care to prevent complications and ensure a safe recovery.
Trust your instincts—if your dog seems unusually weak, distressed, or unable to hold down food or water, getting help promptly gives them the best chance of bouncing back.