What is gastroenteritis in dogs?

Gastroenteritis is one of the most common reasons dogs end up at the vet, and if you’ve ever seen your pup suddenly go off their food, lose their energy, vomit, or have diarrhoea, you’ll know how worrying it can be.

This condition, which simply means inflammation of the stomach and intestines, can strike suddenly and make even the happiest dog feel miserable. The good news is that most cases are treatable, and a little knowledge of the symptoms, causes, and available treatments can help ensure the health and wellbeing of your furry family member.

Gastroenteritis can occur at all ages and stages of life, and it can be an acute condition, coming on seemingly out of nowhere, or chronic, where it develops more slowly and persists for longer.

Acute gastroenteritis

Acute gastroenteritis is a sudden-onset condition and is often caused by eating harmful items (e.g. table scraps or garbage), infections such as parvovirus or protozoa infestation (e.g., Giardia), or even stress.

Treating Giardia often includes a prolonged use of a worming agent combined with antimicrobial treatment. The average treatment cost for Giardia in 2024 was $580 but could be as high as $8,542^Ø.

Chronic gastroenteritis

Chronic gastroenteritis develops over time and is typically triggered by food allergies, underlying diseases, or persistent exposure to stressors.

The average treatment cost for IBD (inflammatory bowel disease) in 2024 was $1,701, with the highest amount being $25,703^Ø.

How common is gastroenteritis in dogs?

Gastroenteritis is one of the most common conditions experienced by dogs. It can affect dogs of all ages and breeds, but it is more prevalent in puppies and senior dogs, and does occur more often in some breeds than others:

Cost of gastroenteritis treatment for dogs

According to PetSure claims data in 2024, gastroenteritis is the second most claimed condition in dogs.

The average cost for treatment in dogs in 2024 was $737, with the highest cost for treatment reaching as much as $32,310^Ø.

As you can see from the table below, the cost of treating gastroenteritis has increased steadly from year to year.

Symptoms of gastroenteritis in dogs

Gastroenteritis usually affects the stomach and intestines, so most symptoms involve digestive upset. Signs can range from mild to severe and may appear suddenly.

Common symptoms include:

• Vomiting – Often frequent or persistent; may contain bile or foam.

• Diarrhoea – Watery or loose stools; sometimes foul‑smelling or discoloured (e.g., with mucus or blood).

• Loss of appetite – Dogs may refuse food or eat less than usual.

• Lethargy – Unusual tiredness or reluctance to play and exercise.

• Abdominal discomfort – Whining, restlessness, stretching, or sensitivity when the belly is touched.

• Dehydration – Sunken eyes, dry gums, or excessive panting caused by fluid loss from vomiting and diarrhoea.

• Fever – Occasionally present with infectious causes.

When to visit the vet

While mild cases may resolve on their own, there are a number of symptoms that indicate a more serious condition, so it’s important that you take your dog to the vet if they occur.  These include:

• Vomiting that won’t stop even though there is nothing left in their stomach, and/or they are vomiting yellow bile.
• They are showing signs they are in pain or distress, including heavy panting.
• They appear particularly weak or lethargic.
• They have blood in their vomit or stool.
• There is the possiblity of them becoming dehydrated due to excessive vomiting.

Unsure how serious it is?

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Causes of gastroenteritis in dogs

Gastroenteritis in dogs can occur for many reasons, ranging from something as simple as eating spoiled food to more serious infections or underlying health conditions.

Here are some of the key reasons why dogs develop this condition:

1. Infections – viral, bacterial or parasitic

Viruses like parvovirus or distemper, bacteria such as Salmonella or E. coli, and intestinal parasites like roundworms or giardia can all cause gastroenteritis. These infections often lead to more severe symptoms, including vomiting, diarrhoea, and lethargy, and may require prompt veterinary treatment.

2. Dietary indiscretions – eating something they shouldn’t

Dogs are naturally curious and often explore with their mouths. Eating spoiled food, garbage, or non‑food items like toys or plants can irritate the stomach and intestines, triggering inflammation. Sudden dietary changes, such as switching foods too quickly or indulging in rich table scraps, are also common culprits.

3. Toxins and poisons

Ingesting toxic substances—such as certain human foods (chocolate, grapes, onions), household chemicals, or poisonous plants—can irritate the digestive tract and damage internal organs. Even small amounts can be dangerous, making quick veterinary intervention essential.

4. Food allergies or intolerances

Some dogs develop sensitivity to specific ingredients, such as certain proteins or grains. These intolerances can cause chronic or recurring gastroenteritis, often accompanied by itchy skin, flatulence, or inconsistent bowel movements. Identifying and removing the trigger ingredient is key to management.

5. Stress and anxiety

Emotional stress—caused by changes in routine, travel, boarding, or new pets in the home—can affect the digestive system. This “stress colitis” can lead to mild, temporary bouts of diarrhoea and is common in otherwise healthy dogs.

6. Underlying medical conditions

Chronic gastroenteritis can also stem from conditions such as inflammatory bowel disease (IBD), pancreatitis, liver disease, or kidney problems. These require thorough diagnosis and ongoing management rather than short‑term treatment.

Diagnosis of gastroenteritis in dogs

Early and accurate diagnosis not only ensures appropriate treatment but also minimises the risk of complications, especially in vulnerable groups like puppies and senior dogs.

To confirm gastroenteritis and rule out other underlying conditions, your vet may conduct a variety of diagnostic tests, including:

1. Physical exam and history

Because gastroenteritis can be caused by many different factors, your vet will start with a physical examination, which may include checking hydration, abdominal pain, temperature, and overall condition.

The vet will also take a detailed history of your dog’s recent diet, environment, and symptoms. This helps identify potential triggers, such as sudden dietary or environmental changes, scavenging, or toxin exposure.

2. Faecal analysis, blood and urine tests

• A stool sample identifies the presence of parasites, bacterial overgrowth, or evidence of an infection.
• Blood tests assess organ function, hydration levels, and detect signs of infection or inflammation, while
• Urinalysis helps to rule out other conditions, such as kidney disease, that can mimic gastroenteritis symptoms.

3. Other diagnostic tests

• Imaging techniques (X-rays or ultrasound): used if a foreign object, blockage, or more serious underlying condition is suspected; helps detect abnormalities in the gastrointestinal tract.
• Endoscopy: allows visual examination of the GI tract and, in some cases, biopsy collection to investigate chronic or severe cases and to retrieve some foreign bodies.
• An elimination diet: may be necessary to uncover potential food allergies.
• Parvovirus test: especially in puppies or unvaccinated dogs with severe vomiting and diarrhoea.

Treatment of gastroenteritis in dogs

The treatment plan depends on the severity of symptoms and underlying cause, but the main goal is to restore hydration, ease discomfort, and allow the digestive system to recover.

Mild cases of gastroenteritis in dogs usually resolve with supportive care, while moderate to severe cases require more medical interventions. Untreated or chronic cases can lead to complications, so early detection and tailored management are both essential.

Here are common approaches to managing gastroenteritis in dogs:

1. Fluid therapy

Rehydration is the cornerstone of treatment, as vomiting and diarrhoea can quickly lead to dehydration. Mild cases may be managed with oral rehydration at home, while more severe cases require intravenous (IV) fluids at the vet clinic to restore electrolyte balance.

2. Medications

Depending on the cause and severity, vets may prescribe:

• Anti-nausea drugs to help control vomiting and reduce nausea.
• Antidiarrhoeal medications to reduce fluid loss.
• Probiotics to assist in restoring a healthy gut microbiome, especially after infections or antibiotic treatments.
• Antibiotics if a bacterial infection is confirmed.

3. Dietary management

Dogs are often placed on a short period of fasting (usually 12–24 hours) followed by a bland diet—commonly boiled chicken and rice or a prescription gastrointestinal diet—to rest the stomach and intestines. Gradual reintroduction of normal food helps prevent relapse.

4. Addressing underlying causes

If gastroenteritis is linked to parasites, toxins, food allergies or another illness, treatment will target that specific cause. For example, deworming medication for parasites or supportive care for pancreatitis.

5. Hospitalisation for severe cases

Dogs with profuse vomiting, bloody diarrhoea, or systemic illness may require hospitalisation for monitoring, IV fluids, and intensive supportive care.

Home care for dogs with gastroenteritis

Most dogs start to feel better within a few days once treatment begins, but careful home management is important to ensure full recovery and prevent relapses.

Here are some things that you can do to help  your dog recover and make them more comfortable:

1. Gradually return to a normal diet

Follow your vet’s instructions on reintroducing food. Typically, dogs start with a bland diet (like boiled chicken and rice or a prescription gastrointestinal formula) for several days before transitioning back to their regular food. Make dietary changes gradually to avoid upsetting the stomach again.

2. Encourage hydration

Ensure fresh water is always available and encourage small, frequent sips. If your dog won’t drink, your vet may recommend oral electrolyte solutions to help maintain fluid balance.

3. Monitor symptoms

Keep a close eye on your dog’s appetite, energy levels, vomiting, and stool consistency. A simple diary of these signs can help you and your vet track progress.

4. Rest and comfort

Provide a quiet, comfortable space where your dog can rest undisturbed. Limit strenuous activity until they have fully recovered.

5. Prevent recurrence

Avoid sudden dietary changes, keep rubbish and toxic foods out of reach, and stay up to date with parasite prevention. Stress‑related cases may improve with routine, enrichment, and gentle reassurance.

6. Call the vet if symptoms worsen

Contact your vet immediately if your dog’s symptoms worsen, they stop eating or drinking, or you notice bloody diarrhoea, ongoing vomiting, or signs of dehydration (dry gums, sunken eyes, lethargy).

Prevention of gastroenteritis in dogs

While not every case of gastroenteritis can be prevented, there are several steps you can take to reduce your dog’s risk:

• Feed a balanced diet – give your dog high-quality, nutritionally complete food and avoid products with by-products, artificial colours, flavours and fillers.

• Avoid table scraps and unsafe foods – human foods, especially fatty or spicy items and foods that your dog isn’t used to, often trigger stomach upset. Keep rubbish and toxic foods (e.g., onions, chocolate, grapes) out of reach.

• Prevent access to spoiled or contaminated items – stop your dog from scavenging, drinking from puddles, or eating unknown objects while out on walks.

• Maintain regular parasite control – routine deworming and flea prevention help protect against gastrointestinal parasites.

• Ensure vaccinations are up to date – vaccines can protect against viral causes of gastroenteritis, such as parvovirus.

• Avoid sudden changes of diet – introduce new foods or treats gradually to allow your dog’s digestive system time to adjust.

• Manage stress – stress can contribute to digestive upset; provide a stable routine and comfortable environment.

• Regular vet check-ups – annual health checks can detect underlying issues that may predispose your dog to gastrointestinal problems.

In summary…

Gastroenteritis in dogs is a common condition that can range from mild stomach upset to a more serious illness. Understanding its causes, recognising the signs early, and seeking prompt veterinary care are key to ensuring a good outcome.

With proper nutrition, routine parasite control, up-to-date vaccinations and careful monitoring of what your dog eats, many cases can be prevented. Being aware and proactive helps keep your dog healthy and comfortable.

Bow Wow Meow Pet Insurance can help protect you and your dog should an unexpected trip to the vet occur.

 

• Find out more about our dog insurance options

• Get an online pet insurance quote

 

    

^∅Based on PetSure claims data, 2024 calendar year. Reimbursement for these claims under a pet insurance policy, would be subject to limits, such as annual benefit limits or sub-limits, benefit percentage, applicable waiting periods and any applicable excess. Cover is subject to the policy terms and conditions. You should consider the relevant Product Disclosure Statement or policy wording available from the relevant provider. Please note that values calculated are based on all claims for that condition and medically related conditions in each calendar year.