It can be confusing and concerning to see your dog throwing up and having diarrhea — yet still running around, playing, and seeming perfectly fine.
You may wonder if it’s something minor or the start of a more serious health issue.
We outline the common reasons why a dog may throw up and have diarrhea but still act normal, what you can do, and when to seek veterinary help.
Dog Throwing Up and Diarrhea but Acting Normal — Why It Happens
When a dog is vomiting and has diarrhea but otherwise acting normal, it’s often due to mild gastrointestinal upset or something they ate that didn’t sit right.
Dogs are curious eaters — a little spoiled food, grass, or a sudden diet change can quickly cause an upset stomach. In many cases, this combination of vomiting and diarrhea is the body’s natural way of eliminating something it doesn’t agree with.
That said, even if your dog seems okay, ongoing vomiting or diarrhea can cause dehydration or reveal an underlying issue such as parasites, food intolerance, or infection.
Paying attention to frequency, duration, and any changes in behavior will help you determine if it’s something that needs a vet’s attention.
Dog Throwing Up and Diarrhea but Acting Normal: Common Causes
Sudden Diet Change
Switching your dog’s food abruptly — even from one high-quality brand to another — can easily cause vomiting and diarrhea.
A dog’s digestive system relies on consistency, and new proteins or fat levels can upset the balance of gut bacteria.
If your dog is otherwise bright and active, a recent diet change is often the culprit. Always transition foods gradually over 7–10 days to avoid gastrointestinal distress. Mixing increasing portions of the new food with the old allows the digestive tract to adapt smoothly.
Read more: Dog Has Bloody Diarrhea but Acting Normal (What It Really Means)
Dietary Indiscretion
One of the most common reasons dogs vomit and have diarrhea while seeming normal is dietary indiscretion — a polite term for eating things they shouldn’t. This can include garbage, table scraps, spoiled food, or objects like grass, tissues, or toys.
When a dog ingests something unusual, their digestive system reacts by trying to get rid of it. Vomiting helps expel what’s in the stomach, and diarrhea clears the intestines. If your dog bounces back quickly and acts normal afterward, it’s likely just mild stomach upset.
However, if symptoms last more than a day or the vomit contains blood, it’s time to see a vet, as foreign objects can sometimes cause blockages or irritation in the gut.
Food Intolerance or Sensitivity
Some dogs develop intolerance to certain ingredients such as beef, chicken, dairy, or grains. When exposed, their system reacts with mild vomiting and diarrhea — but since they’re not in pain or lethargic, they often appear completely fine.
Over time, food sensitivities can worsen if the offending ingredient isn’t removed. If your dog’s digestion improves after removing a suspected trigger food, it’s a good sign of intolerance.
Working with your vet to identify safe proteins or switching to a limited-ingredient diet can help prevent future flare-ups.
Mild Bacterial or Viral Infection
Dogs can pick up minor bacterial or viral infections from contaminated water, soil, or other dogs. These often cause temporary vomiting and diarrhea as the immune system fights off the invader.
If your dog’s energy and appetite remain normal and symptoms clear up within a day or two, it’s likely a mild infection.
However, if vomiting becomes persistent, stools are bloody, or your dog starts acting lethargic, it could indicate a more serious issue like parvovirus or bacterial gastroenteritis — both of which require veterinary care.
Intestinal Parasites
Parasites like roundworms, hookworms, and giardia are common in dogs and can cause chronic vomiting and diarrhea — sometimes with no major change in behavior. These parasites can enter through contaminated soil, water, or feces.
Even though your dog might act perfectly normal, parasites can still affect nutrient absorption and cause gradual weight loss or dull coat quality.
Regular deworming and fecal checks at your vet help catch infections early before they cause lasting harm.
Stress or Excitement
Emotional stress or sudden excitement can also lead to gastrointestinal upset in dogs. Situations like car rides, boarding, fireworks, or moving homes can trigger vomiting or loose stools.
In these cases, the behavior stems from the gut-brain connection — the same way humans might get an upset stomach before a big event. Once your dog relaxes and settles back into routine, the symptoms usually resolve on their own.
Read more: Dog Pooping Bloody Mucus but Acting Normal (Here’s why)
What to Do If Your Dog Is Throwing Up and Has Diarrhea but Acting Normal
If your dog has mild vomiting and diarrhea but is otherwise alert, playful, and drinking water, you can often manage the situation at home.
Start by withholding food for about 8–12 hours (but never water) to let the stomach rest. After that, reintroduce a bland diet — boiled chicken and plain white rice are gentle on the stomach.
Feed small portions every few hours and gradually transition back to their regular food once stools begin to firm up.
Encourage hydration by offering clean water or unflavored Pedialyte if recommended by your vet. Dehydration can sneak up quickly, even when your dog seems fine.
Keep an eye on their bowel movements and energy levels. If they vomit more than twice, diarrhea persists for over 48 hours, or they refuse food or water, it’s time for a professional checkup.
Avoid giving over-the-counter medications unless specifically instructed by your vet, as some human meds can be toxic to dogs.
When to Call or Visit Your Vet
Even if your dog seems normal, certain signs mean you shouldn’t wait.
If vomiting and diarrhea last longer than two days or come with blood, lethargy, abdominal pain, or refusal to eat or drink, it’s important to get veterinary care right away. Persistent digestive issues can lead to dehydration and electrolyte imbalances that worsen quickly.
Seek immediate help if your dog’s vomit looks like coffee grounds (which can indicate internal bleeding) or if diarrhea is black, tar-like, or contains bright red streaks. These are signs of possible intestinal bleeding or severe irritation.
Puppies, senior dogs, and those with chronic illnesses like diabetes or kidney disease are at higher risk of complications and should be checked sooner, even if they appear normal.
Read more: Dog With Loose Stools but Acting Normal (When to Worry)
Key Takeaway
If your dog is throwing up and has diarrhea but otherwise acting normal, it’s often just a short-term digestive upset caused by something they ate or a minor stomach bug. With rest, hydration, and a gentle diet, most dogs recover within a day or two.
However, don’t ignore the symptoms if they persist, worsen, or involve blood — these could be signs of something more serious brewing beneath the surface.
When in doubt, trust your instincts and consult your veterinarian. Catching issues early helps keep your dog’s tummy — and tail — happy and healthy.