Gastroenteritis in Dogs: Causes, Symptoms & Treatment

Dr. Jason Gagné, DVM, DACVIM
By Dr. Jason Gagné, DVM, DACVIM
Updated: 6/24/20242-4 minutes
girl smiling while petting a black and tan dog

The signs of gastroenteritis in dogs may seem startling. The most common symptoms vomiting and diarrhea can make any pet owner concerned. Fortunately, dog gastroenteritis is a fairly common condition that is often treatable.

Be careful not to ignore it, though. Loose stool and vomiting aren’t unique to one condition. While your pet’s digestive upset may not be cause for panic, it’s also possible they have a serious underlying illness.

Here’s what you should know about the causes, symptoms and treatment for gastroenteritis in dogs.

What is Gastroenteritis in Dogs?

Dog gastroenteritis is an inflammation of your pet’s gastrointestinal (GI) tract (i.e., stomach and small intestine). It’s characterized by diarrhea and usually accompanied by vomiting, among other symptoms.

In acute cases, symptoms may worsen but generally don’t last long; they often go away on their own. Chronic cases tend to persist for more than two weeks.

What Causes Gastroenteritis in Dogs? 

GI inflammation in dogs can be caused by several things including: 

  • Your dog ate unsafe food. This could be food that’s spoiled or harmful to dogs
  • Ingesting a foreign object. Curious canines who like to munch on more than just food (e.g., household objects or your shoes) may cause themselves harm. 
  • GI ulcers. You may see blood in your pet’s vomit or stool. 
  • Toxins. Certain foods, plants and chemicals are dangerous for dogs. 
  • Bacteria or viruses. Parvovirus, among other illnesses, can trigger vomiting and diarrhea. 
  • Parasites. Intestinal parasites such as roundworms are associated with GI upset. 
  • Food intolerance. Some dogs are sensitive to specific ingredients.

What is Acute Hemorrhagic Diarrhea Syndrome (AHDS) in Dogs?

Acute Hemorrhagic Diarrhea Syndrome (AHDS), also known as hemorrhagic gastroenteritis (HGE), is an acute (sudden) disorder of dogs characterized by vomiting and bloody diarrhea.

AHDS is very serious. It often affects small or toy breeds (but any breed can be affected), and requires immediate medical attention. If left untreated, a dog with AHDS may die.

Gastroenteritis in Dogs – is it Contagious? 

In some cases, the cause of gastroenteritis in dogs may be zoonotic (contagious to humans). This can happen when the condition is caused by a bacterial infection such as e.coli or salmonella.

AHDS, on the other hand, while serious, isn’t considered contagious.

Dog Gastroenteritis Symptoms 

Remember, the primary signs of gastroenteritis are diarrhea and vomiting. There are, however, some other symptoms to watch for: 

  • Lethargy 
  • Stomach pain 
  • Lack of appetite 
  • Dry heaving or gagging 
  • Dehydration (excessive panting or dry gums)

Diagnosing Gastroenteritis in Dogs

There are a few ways you can determine if your dog has gastroenteritis.

First, note the symptoms. If they start having diarrhea and are throwing up, this may be a clear sign. Also, when examining their stool, is it healthy poop or does it look watery and loose?

A thorough inventory of diet history and environmental changes can help aid in determining the cause. 

Ultimately, your veterinarian can make a formal diagnosis. They’ll check for additional clinical signs and may conduct fecal testing, bloodwork or X-rays.

These tests can help them rule out more serious conditions such as parasites, intestinal obstructions and other diseases.

Again, if you see blood in your dog’s stool or vomit (which can resemble coffee grounds), contact your veterinarian as soon as possible.

Dog Gastroenteritis Treatment

Treatment for gastroenteritis in dogs will depend on the cause.

If your veterinarian determines the condition is acute and non-life-threatening, they may recommend withholding food for 24 hours or so. This will help the GI tract rest and recover.

Keeping your pet hydrated is key, as they lose a lot of fluids and electrolytes through vomiting and diarrhea.

In more mild cases of gastroenteritis (especially those without vomiting), your dog can drink water in moderation. In more severe cases, intravenous fluids may be required.

Once it’s time to reintroduce food, offer it in small amounts, several times per day. Gradually transition back to their normal feeding schedule over a few days.

Depending on the seriousness of your dog’s upset stomach, your veterinarian may prescribe medication.

While it may be tempting to try a gastroenteritis in dogs home treatment, always check with your veterinarian first. You don’t want to accidentally worsen your pet’s condition with over-the-counter remedies.

Gastroenteritis in Dogs – Recovery Time 

Recovery time depends on the cause and severity of symptoms.

In more mild, acute cases, the condition may resolve itself within a couple days. More severe instances or instances related to an underlying medical condition might take longer.

Preventing Gastroenteritis in Dogs 

If you’re not sure what triggered your dog’s gastroenteritis, finding the right prevention tactic can be tricky. There are some general guidelines you can follow, however.

Try to Prevent Scavenging 

If your dog munches on every food scrap they find on a walk, discourage this behavior. Discarded food may be spoiled or harmful to pets.

Stay Current With Vaccinations

Vaccinations are important for keeping your pet healthy. In particular, vaccinating against parvovirus a contagious and potentially deadly virus for dogs can eliminate one possible cause of gastroenteritis.

Consider Deworming Medication 

Roundworms and other intestinal parasites are known to cause vomiting and diarrhea, among other symptoms. Regular deworming medication reduces the chances of an infection. Ask your veterinarian for a recommendation.

If you’re wondering, Can dogs get stomach bugs?, because your pet has symptoms of digestive upset, they may be experiencing gastroenteritis.

Diarrhea, vomiting, lethargy and stomach pain these are all signs that your dog likely needs medical attention (especially if you see blood). Contact your veterinarian for a formal diagnosis and treatment plan to help your pet.

Want additional canine care tips? Explore our other dog health articles for more advice from our experts.


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