It’s alarming when your dog suddenly refuses to eat and shows signs of an upset stomach. These two symptoms together can signal anything from minor digestive issues to serious health problems that need medical attention.
We outline the common causes of a dog’s has upset stomach and not eating, what you can do at home, and when to seek veterinary help.
Dog Upset Stomach and Not Eating — Why It Happens
An upset stomach and loss of appetite often go hand in hand in dogs, especially when the body is reacting to something irritating or harmful. This could include dietary indiscretion (eating garbage), infections, parasites, pancreatitis, stress, or chronic gastrointestinal diseases.
Dogs may also experience nausea, vomiting, diarrhea, and lethargy alongside their upset stomach, all of which contribute to them refusing food.
The underlying causes can range from mild and self-limiting to life-threatening conditions that require prompt treatment.
Dog Upset Stomach and Not Eating: Common Causes
Dietary Indiscretion
Dogs are notorious for getting into the trash or eating things they shouldn’t.
Spoiled food, fatty table scraps, or ingesting non-food items can irritate the stomach and cause vomiting, diarrhea, or general gastrointestinal distress. Your dog may act nauseated and refuse to eat while their body tries to recover from the offending item.
Mild cases often resolve on their own, but severe reactions can lead to dehydration or pancreatitis.
Gastroenteritis
This is inflammation of the stomach and intestines and is a common reason for upset stomach and appetite loss.
It may be caused by bacteria, viruses, or food allergies. Dogs with gastroenteritis may also vomit, have loose stools, or become lethargic.
Because the gastrointestinal tract is inflamed, eating can worsen discomfort, leading them to avoid food.
Persistent symptoms or signs of blood in vomit or stool require urgent vet care.
Read more: Dog Vomiting and Not Eating (Here’s what might be going on)
Parasites
Intestinal worms or protozoa can upset your dog’s digestive system and interfere with nutrient absorption.
A parasitic infection may cause nausea, soft stool, weight loss, bloating, and disinterest in food. Puppies and dogs with weakened immune systems are especially vulnerable. Routine deworming and fecal checks can help prevent recurring issues.
Left untreated, parasites can cause chronic digestive issues and malnutrition.
Pancreatitis
Pancreatitis is a painful inflammation of the pancreas often triggered by eating fatty foods.
It can cause severe abdominal discomfort, vomiting, diarrhea, lethargy, and refusal to eat. Some dogs will stand with their front end lowered in a “prayer position” due to abdominal pain. This condition can range from mild to life-threatening and always warrants veterinary assessment.
It’s particularly common in smaller breeds like Miniature Schnauzers or Yorkshire Terriers.
Stress or Anxiety
Just like people, dogs can experience stomach upset when stressed.
A change in routine, boarding, new environments, or the absence of their owner can all trigger gastrointestinal upset. Symptoms include mild diarrhea, nausea, pacing, or hiding. While stress-induced stomach upset usually resolves within a day or two, prolonged anxiety can lead to ongoing appetite issues.
Behavioral support and calming techniques may help in these cases.
Chronic GI Conditions (e.g., IBD)
Some dogs develop chronic digestive disorders like inflammatory bowel disease (IBD).
These conditions cause recurring episodes of vomiting, diarrhea, or nausea, often leading to a reduced appetite. If your dog has frequent digestive upset or loses weight over time, chronic GI conditions should be considered.
They often require a combination of prescription diets and medications to manage.
What to Do If Your Dog Has Upset Stomach and Not Eating
If your dog’s symptoms are mild and they’re still drinking water, try withholding food for 12–24 hours to allow the stomach to settle.
After fasting, offer a bland diet like boiled chicken and white rice in small amounts. Monitor their response closely—if symptoms improve, gradually reintroduce regular food over a few days.
Encourage hydration with fresh water or unflavored electrolyte solutions. You can also try giving small amounts of plain canned pumpkin to soothe the digestive tract.
Avoid giving treats, fatty foods, or human medications. If your dog seems nauseated (licking lips, drooling), your vet may prescribe anti-nausea medication to help restore appetite.
When to Call or Visit Your Vet
Seek veterinary help if your dog:
Vomits repeatedly or has bloody vomit/stool
Appears bloated or in significant pain
Is lethargic or weak
Shows no interest in water
Has had no improvement in 24 hours
Is a puppy, senior, or has other health conditions
These signs suggest something more serious may be going on that requires professional evaluation and possibly diagnostics like x-rays or blood work.
Read more: Dog Diarrhea and Not Eating (Should you worry?)
Key Takeaway
An upset stomach paired with loss of appetite can be a sign of anything from a simple dietary mistake to a serious medical condition.
While some cases are mild and resolve with at-home care, others can progress quickly and become dangerous without treatment. Always monitor your dog closely and don’t hesitate to reach out to your vet when in doubt.
Your dog depends on you to notice when something isn’t right—and getting help early can make all the difference.