Causes and Management of Gastritis in Dogs

DigestiveQ&AMeongsiljang Veterinary Advisory Board

We’ve compiled a comprehensive guide based on veterinary textbooks, covering the acute and chronic causes of gastritis in dogs, a symptom checklist, when to visit the vet, and dietary management tips you can follow at home.

Canine Gastritis: Causes and Management

A dog lying on a blanket, feeling uncomfortable in its stomach.

Most cases of canine gastritis are acute and stem from dietary indiscretion, such as scavenging from trash cans or eating human food, which inflames the stomach lining. Acute gastritis typically resolves within a few days once the underlying cause is removed and symptomatic treatment is provided. However, if vomiting persists for several weeks or more, chronic gastritis should be suspected. Because chronic gastritis often involves complex causes like food allergies or immune-mediated reactions, thorough diagnostic testing is necessary. This article covers the causes of both acute and chronic gastritis, a symptom checklist, and guidance on treatment and home dietary management.

Main Causes of Acute Gastritis

According to veterinary internal medicine textbooks, the most common cause of acute gastritis is dietary indiscretion. Typical examples include eating food picked up during walks or consuming spoiled food.

Dietary indiscretion: Eating spoiled food or greasy human foods can irritate the stomach lining.

Ingestion of foreign objects: Swallowing toy fragments, bones, or plastics can physically damage the stomach wall.

Drug side effects: Medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) can weaken the protective layer of the stomach lining.

Toxic substances: This occurs when pets lick or ingest detergents, toxic plants, or chemicals.

Food hypersensitivity: Some pets may have sensitive stomachs that react adversely to specific pet foods or treats.

Acute gastritis typically improves within a few days once the underlying cause is quickly removed.

What Causes Chronic Gastritis?

Chronic gastritis is a condition in which vomiting persists for several weeks to months or longer. Unlike acute gastritis, it is often difficult to pinpoint a single underlying cause. According to veterinary internal medicine textbooks, the main causes of chronic gastritis include:

Food allergy: An immune response to a specific protein source leads to chronic inflammation of the gastric mucosa.

Immune-mediated reaction: The immune system overreacts against the gastric mucosa, causing chronic inflammation (e.g., lymphoplasmacytic gastritis).

Part of inflammatory bowel disease (IBD): Inflammation may extend beyond the stomach to involve the entire gastrointestinal tract.

Helicobacter infection: While a major cause of gastritis in humans, its role in actually causing disease in dogs has not yet been definitively proven.

Interestingly, some dogs show no clinical signs at all, even when gastric inflammation is confirmed on histopathology.

A puppy hesitating in front of its food bowl

Symptom Checklist for Gastritis in Dogs

The symptoms of gastritis in dogs can vary slightly depending on whether the condition is acute or chronic. Use the following points to assess your pet’s current state.

Intermittent vomiting: Acute cases tend to start suddenly, while chronic cases often recur at intervals of several days.

Bile vomiting on an empty stomach: In chronic gastritis, you may notice a pattern where your dog vomits yellow bile when fasting, with symptoms improving after eating.

Grass eating: You might observe your dog nibbling on grass when feeling unwell, though the exact reason for this behavior remains unclear.

Decreased appetite: Your dog may hesitate in front of their food bowl or stop eating midway through a meal.

Abdominal discomfort: Your dog may tense up when their belly is touched or assume a prayer position (stretching the front legs forward while keeping the hindquarters elevated).

Weight loss: If chronic gastritis persists over a long period, gradual weight loss may occur.

Go to the Vet Immediately If You See These Symptoms

If you notice blood in the vomit (or a coffee-ground appearance), if your pet hasn’t been able to keep down water for more than a day, or if you see signs of dehydration such as dry gums and skin that doesn’t snap back when gently pinched, it’s an emergency. Immediate veterinary care is also necessary if you suspect your pet has swallowed a foreign object. In particular, if your dog appears severely lethargic or shows extreme pain when you touch its abdomen, there may be a risk of gastric perforation or intestinal obstruction, so don’t delay seeking help.

How Is It Diagnosed at the Vet?

If your dog is suspected of having gastritis, the veterinarian will proceed with step-by-step examinations. First, blood and urine tests are conducted to assess overall health. In cases of chronic gastrointestinal disease, abnormal findings such as anemia or hypoproteinemia may appear, but blood test results often come back normal. If a foreign body is suspected, an X-ray or ultrasound is used to examine the inside of the stomach. If chronic vomiting persists for several weeks or more, an endoscopy is the most accurate diagnostic method. With an endoscopy, the veterinarian can directly observe the condition of the stomach lining and collect tissue samples to determine the type of inflammation. Acute gastritis is usually resolved with symptomatic treatment alone without the need for detailed examinations. However, if vomiting recurs or your dog loses weight, be sure to have them undergo a thorough examination.

How Is Treatment Carried Out?

Acute gastritis usually responds well to symptomatic treatment. Your veterinarian will prescribe antiemetics and acid-suppressing medications based on your pet’s weight, and administer fluid therapy if dehydration is severe. Treatment for chronic gastritis depends on the underlying cause. If a food allergy is suspected, we typically trial a hydrolyzed protein diet or a novel protein diet for about two weeks. If symptoms do not improve within two weeks, we may try another novel protein diet for an additional two weeks, or initiate immunosuppressive therapy under veterinary guidance. When immunomodulatory drugs (such as glucocorticoids) are used for immune-mediated inflammation, the dosage is gradually tapered over several months. If a foreign body is the cause, it may be removed via endoscopy, or surgery may be required depending on its size and location. Under no circumstances should you administer human medications to your pet without veterinary guidance.

A puppy receiving treatment from a veterinarian

Dietary Management at Home

Dietary management during the recovery phase from gastritis is just as important as medical treatment.

Immediately after acute gastritis: Depending on your veterinarian’s assessment, withhold food for 12–24 hours, then offer small amounts of low-fat foods such as boiled chicken breast and white rice, divided into 4–5 meals per day. Gradually transition back to the regular diet over 3–5 days.

Managing chronic gastritis: Divide the daily food ration into 3–4 meals to reduce gastric burden. Strictly limit high-fat treats and human food, and consistently feed a gastrointestinal prescription diet recommended by your veterinarian.

If fasting-induced vomiting is frequent: Offering a small treat before bedtime or advancing the morning feeding time can help minimize irritation to the empty stomach.

Key Points to Prevent Recurrence

Gastritis is a condition that tends to recur frequently. Replace your trash can with one that has a locking mechanism, and be careful to prevent your pet from eating food off the ground during walks. When introducing new food or treats, transition gradually over 3 to 5 days. Never feed onions, grapes, or greasy human foods. Regular health check-ups are also important for the early detection of chronic gastritis.

Reviewed by a veterinarian

Dr. Tony — Punnawat Phongkittirak

Veterinarian

A veterinarian who majored in veterinary medicine at Khon Kaen University, Thailand, and completed the IVSA program at North Carolina State University in the United States. Drawing on clinical experience at animal hospitals, he works in the pet healthcare field and is dedicated to building a digital care environment that connects pet parents with veterinarians.

Frequently Asked Questions

Does every time a puppy vomits mean it has gastritis?

Not necessarily. Vomiting can be caused by a variety of factors beyond gastritis, including ingestion of foreign objects, pancreatitis, kidney disease, and infections. If vomiting persists for more than a day or is accompanied by other symptoms, it's best to have your pet examined by a veterinarian.

How long does a dog stay sick with gastritis?

Acute gastritis usually improves within a few days once the underlying cause is removed and proper care is provided. Chronic gastritis, on the other hand, can persist for several weeks to months, so it’s important to work with your veterinarian to develop a long-term management plan.

Are there specific foods that are good for gastritis?

During the recovery phase of acute gastritis, low-fat, easily digestible foods such as boiled chicken breast and white rice are recommended. For chronic gastritis, hydrolyzed protein diets or gastrointestinal prescription diets recommended by your veterinarian can be helpful.

Can a dog's gastritis be transmitted to humans?

General canine gastritis is not contagious to humans. The Helicobacter species found in dogs are often different from H. pylori, which causes gastritis in humans, and there is currently limited evidence regarding cross-infection between dogs and humans. If you have family members with weakened immune systems, we recommend consulting with a veterinarian.

Can I give probiotics to help prevent gastritis?

Probiotics for pets can help improve gut health. However, human probiotics differ in bacterial strains and dosage, so always consult your veterinarian before giving your pet a product specifically formulated for animals.

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References

[1] Schaer M. & Gaschen F., Clinical Medicine of the Dog and Cat, 4th Edition — Chapter 9: Diseases of the Stomach, CRC Press

[2] Ramsey I. & Tennant B., Notes on Canine Internal Medicine, 4th Edition — Section 5.1: Gastritis, Wiley-Blackwell

[3] Little S., The Dog Care Handbook: Things I Wish My Vet Had Told Me — Gastro-intestinal Disease, 2024