Gastroenteritis in Dogs: Gastroenteritis is when …

What does it mean when your veterinarian diagnoses your dog with gastroenteritis?

Isn’t that a mouthful? Sometimes it seems the vets use these terms specifically to baffle us! In their defense, medical terms are actually highly descriptive once you figure out how to decipher them.

Gastroenteritis in Dogs: Gastroenteritis is when ...

Frequent diagnosis

If you own a dog, gastroenteritis is a term that you might run into often enough.

You bring your dog into the veterinary clinic with diarrhea and vomiting. The chances that your vet will spring this word on you are pretty good. So what does it mean?

I don’t know why—I blame my goofy bone—every time I come across this word I think of how a student who didn’t do his homework would tackle explaining it: “Gastroenteritis is … When … something bad enters the digestive system.”

What grade do you think he’d deserve for that? Let’s take a look.

What does the term really mean?

Gastroenteritis refers to inflammation of the stomach and intestines.

The faithful suffix -itis stands for inflammation (e.g., arthritis, pancreatitis, gingivitis …).

Gastroenteric refers to the stomach and intestines – gastrointestinal (GI). Sorry, nothing about any actual entering.

However, the most common cause of gastroenteritis in dogs is a dietary indiscretion, which actually is something inappropriate entering the system. Ha! It can also be caused by drugs, poisoning or infection.

Considering all that, I think our unprepared student deserves a C for his efforts.

Is it a useful diagnosis?


Because of its many different possible causes and how it can vary greatly in its severity, gastroenteritis is actually quite a broad term.

Something makes the GI tract angry, and it triggers a defensive mechanism – inflammation. Some of the many causes are

  • dietary indiscretion
  • an abrupt change in diet (you’ve heard about gradual switching, haven’t you?)
  • poisoning
  • infections
  • food allergies
  • autoimmune disease

Quite a list, isn’t it?

You are most likely to face the acute form of gastroenteritis, but it can also have a chronic form.

The symptoms of vomiting, diarrhea, and loss of appetite may wax and wane, but they linger over weeks or months.

Is it serious?

It can be.

The rule of thumb is the violence of the symptoms and how long they last.

Violent diarrhea and vomiting, the presence of blood, pain, fever, dehydration, lethargy, these are all signs that it’s time to take action immediately. If the symptoms are relatively mild but chronic, you also want to pay attention and investigate the cause.

I was tempted to call for common sense, but is it still common sense when it’s not so common?

What to do?

I know people who run to the vet at the drop of a hat and I know people who shrug off quite violent lasting symptoms. Neither is a good idea, but when you’re in doubt, err on the side of caution. It is better to rush to a vet with a simple garbage gut than to ignore a potentially life-threatening situation!

While acute symptoms are likely to get your attention, it is often easy to ‘come to terms’ with a chronic situation.

I know, I’ve been there. It is not that we didn’t take Jasmine to vets. We did. But after countless fruitless visits, we accepted the lack of diagnosis. That was the wrong thing to do, and Jasmine paid for that. Chronic diarrhea is not normal! Where there is a symptom, there is a cause.

What is the best treatment?

Also, beware of arbitrary symptom-based treatment.

While there is a time and place for that approach, without a firm diagnosis, it can do more harm than good.
Moderate diarrhea that lasts a day or two is likely nothing to be overly concerned about. I do worry when diarrhea is accompanied by vomiting though. Dr. Beatty’s article gives a good of example why it is a good idea to take this seriously.

Our J.D. is a young healthy dog who’ll eat about anything that fits in his mouth. 

When he gets diarrhea, I have very clear suspicions. I put him on a 24 hour fast and all is well the next day. Sometimes he also does throw up. However, examining the vomit always makes it quite obvious why.

Jasmine is a different story. Even when her diarrhea isn’t really bad, a 24 hour fast has never worked for her, and medical treatment has always turned out necessary.

Related articles:
Diarrhea/Runny Stools in Dogs: Why Is My Dog’s Poop Runny?
Symptoms to Watch for in Your Dog: The Big Picture
Treating Dog Diarrhea at Home

Further reading:
Gastroenteritis in Dogs

Categories: ConditionsGastroenteritis

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Jana Rade

I am a graphic designer, dog health advocate, writer, and author. Jasmine, the Rottweiler of my life, was the largest female from her litter. We thought we were getting a healthy dog. Getting a puppy from a backyard breeder was our first mistake. Countless veterinary visits without a diagnosis or useful treatment later, I realized that I had to take Jasmine's health care in my own hands. I learned the hard way that merely seeing a vet is not always enough. There is more to finding a good vet than finding the closest clinic down the street. And, sadly, there is more to advocating for your dog's health than visiting a veterinarian. It should be enough, but it often is not. With Jasmine, it took five years to get a diagnosis. Unfortunately, other problems had snowballed for that in the meantime. Jasmine's health challenges became a crash course in understanding dog health issues and how to go about getting a proper diagnosis and treatment. I had to learn, and I had to learn fast. Helping others through my challenges and experience has become my mission and Jasmine's legacy. I now try to help people how to recognize and understand signs of illness in their dogs, how to work with their veterinarian, and when to seek a second opinion. My goal is to save others the steep curve of having to learn things the hard way as I did. That is the mission behind my blog and behind my writing. That is why I wrote Symptoms to Watch for in Your Dog, which has turned out being an award-winning guide to dog owners. What I'm trying to share encompasses 20 years of experience.

  1. This is very helpful advice for someone who isn’t sure if they should call the vet or not. I always check Symptoms to Watch for in Your Dog when my dog seems unwell, but it doesn’t seem to be an emergency situation. It helps me decide if it is a call the vet now problem or not.

  2. I’m one of those who takes my cats to the vet when they are vomiting or have diarrhea because I know how quickly they can go downhill. Gastroenteritis sounds like a generic term similar to Upper Respiratory Infection that I just talked about.

    • Yes, cats have even a tougher deal; I don’t know that much about cats but it seems that a cat with no nutrients is heading for fatty liver.

  3. I am fortunate I can email my vet if this happens before i take Layla to the vet and in the past when she did have an upset tummy he told me to give her chicken with probiotics which works wonders for her so I can keep them in the house for emergencies. Great post

  4. One thing comes through for me, if you know your dog well this helps you take the best first steps.

    I might find diarrhea a bit of a worry but I would find vomiting a cause for immediate concern and a trip to the vet. Especially with your important list of possible causes that goes way beyond simply eating the wrong thing.

  5. I’ve never heard of gastroenteritis before. And YES that is quite the mouthful. My first instincts were ” This must be related to food poisoning.” but as I read more I can see that’s just one factor to take into account. I fully agree about taking your pet to the vet just in case, even it if may be futile. Better to be safe than sorry. Thanks for sharing this info. I always learn something new.

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