Gastritis in Cats: Symptoms, Causes & Treatment (2026)

What Is Gastritis?

Gastritis is inflammation of the gastric mucosa — the lining of the stomach. When this lining becomes irritated or inflamed, it disrupts the stomach's ability to produce protective mucus, regulate acid secretion, and empty normally. The result is nausea and vomiting.

Gastritis in cats falls into two broad categories:

• Acute gastritis: Sudden onset from a dietary cause or transient irritant. Typically self-limiting within 24–48 hours. The cat is otherwise well.
• Chronic gastritis: Recurring or persistent vomiting over weeks to months. Almost always indicates an underlying condition — systemic disease, IBD, or food intolerance — that needs diagnosis and targeted treatment.

The critical issue with cats is that vomiting is so common and so readily normalized by owners that underlying conditions frequently go undetected for months. A cat vomiting once a week for six months is not experiencing “normal cat behavior” — it is experiencing chronic inflammation that warrants investigation.

Signs and Symptoms

The character of the vomit provides useful information:

• Undigested or partially digested food — vomited shortly after eating; suggests the stomach is not retaining food normally
• Yellow or green bile — stomach is empty; bile is refluxing from the small intestine. Common first thing in the morning in cats with IBD or bilious vomiting syndrome.
• Frothy white foam — air and gastric secretions; stomach is empty and irritated
• Hairball material — cylindrical mass of fur; may be normal but frequent hairball vomiting can also indicate abnormal GI motility
• Brown “coffee ground” material or frank blood — indicates GI bleeding; requires prompt veterinary care

Other signs associated with gastritis:

• Lip-licking and repeated swallowing — behavioral signs of nausea in cats
• Drooling or hypersalivation
• Reduced appetite or complete food refusal
• Lethargy and reduced activity
• Weight loss — particularly in chronic gastritis; cats can lose significant muscle mass over weeks
• Hunched posture or guarding the abdomen when touched

Causes of Gastritis in Cats

Acute Gastritis

Causes of a one-off vomiting episode:

• Eating too fast (scoffing food, then immediately vomiting it back up)
• Hairballs — accumulated fur irritating the stomach
• Dietary indiscretion — though cats are more selective than dogs
• Sudden food change — abrupt transitions disrupt the gastric environment
• Medications — NSAIDs and some antibiotics irritate the stomach lining
• Infectious gastroenteritis — bacterial or viral, often with concurrent diarrhea

Chronic Gastritis

Recurrent or persistent vomiting in cats should trigger a systematic investigation. The most common underlying causes:

What Bloodwork Shows

Bloodwork in cats with gastritis primarily serves to rule out systemic causes — not to confirm gastric inflammation itself, which requires endoscopy. The most important addition for any senior cat is a T4.

How Vets Diagnose Chronic Vomiting in Cats

A single vomiting episode in an otherwise healthy cat is usually managed empirically — a brief food rest, then bland food, and monitoring. Recurring vomiting requires a systematic workup:

Treatment

Acute Gastritis at Home

For mild, one-off vomiting in an otherwise healthy cat:

• Brief food rest: 2–4 hours maximum. Water remains available.
• Bland diet: Small, frequent meals of boiled chicken (no skin, no seasoning), or a prescription GI diet (Hill's i/d, Royal Canin GI). Feed 3–4 small amounts rather than one full meal.
• Monitor closely: If vomiting continues after the first few small bland meals, or if the cat refuses to eat at all, contact a vet rather than continuing to wait.

Veterinary Treatment

IBD vs. Small Cell Lymphoma: Why the Distinction Matters

The most important diagnostic challenge in feline chronic GI disease is distinguishing inflammatory bowel disease from small cell (low-grade) lymphoma. They share nearly identical clinical presentations: chronic vomiting, weight loss, and sometimes diarrhea. On bloodwork, both may show low cobalamin and low albumin. On ultrasound, both can show thickened intestinal walls.

The distinction requires biopsy. IBD shows inflammatory cell infiltration with intact mucosal architecture; lymphoma shows a monoclonal population of neoplastic lymphocytes. Immunohistochemistry (IHC) and PARR testing on biopsy samples confirm the diagnosis in ambiguous cases.

The distinction matters for two reasons:

• Treatment differs: IBD is managed with immunosuppression alone (prednisolone ± azathioprine or cyclosporine). Small cell lymphoma is treated with chlorambucil and prednisolone — a different protocol.
• Prognosis differs: Both carry reasonable long-term outcomes when treated, but lymphoma has a defined disease trajectory whereas IBD is managed rather than cured. Knowing which one you are dealing with shapes long-term monitoring and owner expectations.

Importantly, small cell lymphoma is not a death sentence. Median survival times of 2–3 years are reported, and many cats maintain excellent quality of life on chlorambucil therapy. The goal of biopsy is not to receive bad news — it is to get the right diagnosis so the right treatment can be started.

Prognosis

Acute gastritis resolves quickly with supportive care. Prognosis is excellent.

Food-responsive chronic gastritis carries an excellent prognosis with appropriate dietary management. Many cats remain in remission indefinitely on a consistent hydrolyzed or novel protein diet.

IBD is manageable but requires ongoing treatment. Most cats do well on prednisolone; some achieve long-term remission with dietary management plus low-dose immunosuppression. Periodic flares can occur.

Small cell lymphoma has a median survival of 2–3 years with treatment — a meaningful outcome for a senior cat. Many cats live comfortably on chlorambucil with minimal side effects.

Gastritis secondary to hyperthyroidism or CKD improves when the primary condition is well managed, though anti-nausea support is often needed long-term.