Gastroenteritis in Cats


Gastroenteritis is a general term referring to inflammation of the stomach and intestines that presents as an “upset stomach” characterized by vomiting, appetite loss, and diarrhea.  Gastroenteritis often results when a cat eats something new or inappropriate, but is also associated with a number of underlying conditions like inflammatory bowel disease, food allergies, and parasites. 

A gastroenteritis diagnosis in and of itself is not particularly useful because it doesn’t identify the underlying cause or guide treatment beyond symptomatic care like fasting, bland diets, and antiemetics. Complicated cases require a more aggressive diagnostic approach to identify the cause of inflammation and guide specific treatment. Bloodwork, diagnostic imaging, endoscopy, and biopsies are utilized to identify any underlying medical conditions. Common therapeutic options include medication, hospitalization, surgery, and nutritional therapy.

Risk Factors

Mild gastroenteritis is common. Most cases are due to nothing more serious than eating something unusual or inappropriate. These mild cases resolve quickly on their own. In rare cases, gastroenteritis may be associated with a life threatening condition such as GI blockage or poisoning.

Gastroenteritis is a more significant concern when the symptoms persist for more than 24 hours, recur frequently over time, or are accompanied by other symptoms such as weight loss or blood in the stool/vomit. 

While medically specific, a diagnosis of gastroenteritis is not particularly useful to pet parents because it does not identify the underlying cause of the inflammation. A more specific diagnosis is necessary for anything beyond symptomatic therapy like antiemetics, fasting, and bland diets.

Possible Causes

Mild, self-limiting gastroenteritis is most commonly caused by eating something unusual or inappropriate.  

Common underlying conditions that lead to gastroenteritis include: 

• Toxin ingestion • Inflammatory bowel diseaseFood allergiesCancer • Food intolerance

• Food poisoning • Gastrointestinal parasites (worms)• Diabetes mellitus Hypoadrenocorticism


Main Symptoms

The primary symptoms of gastroenteritis include

VomitingDiarrhea • Appetite loss • Weight loss

Detailed Characterization

Some of the possible underlying causes of gastroenteritis (as listed above) are severe and potentially life-threatening with a multitude of associated symptoms including: 

• Excessive hairball production • Bloody vomit (hematemesis) • Bloody diarrhea (melena and hematochezia)

• Rapid heartbeat and a weak pulse (hypovolemia) • Pale gums (anemia, associated with gastrointestinal ulcers)

• Abdominal pain

Testing and Diagnosis

A specific diagnosis of gastroenteritis requires a biopsy from the lining of the stomach and intestines. In most cases the clinical suggestion of the condition is sufficient and it is not necessary to get a confirmed diagnosis. 

Mild, uncomplicated cases typically go away quickly on their own or with symptomatic therapy, so no additional diagnostic testing is necessary.   Cats with more severe or chronic symptoms progress through increasingly complicated diagnostic tests as needed until the cause of the gastroenteritis is identified:  

• Physical examination • Blood tests • Fecal analysis • Endoscopy • Biopsy

• Diagnostic imaging (x-rays and ultrasound)

Additional diagnostics and treatment for more complicated cases depends on the specific underlying condition.

Steps to Recovery

Symptomatic treatment of gastroenteritis includes: 

• Fasting (GI rest) • Bland diets  • Antiemetics • Digestive protectants • Probiotics

• Dewormers and antiprotozoals • IV fluids • Antibiotics

Duration of symptoms will vary depending on the root cause. A cat with simple, acute gastroenteritis is expected to improve with symptomatic therapy within 48 hours, but a cat with inflammatory bowel disease needs long-term care.


Gastroenteritis is contagious in some cases (and potentially zoonotically), depending on the cause. Some of the diseases that cause gastroenteritis have vaccinations available. Most contagious diseases that cause symptoms of vomiting and diarrhea are spread in those fluids, so isolation of sick pets is important for preventing disease transmission. Diligent storage of non food and inappropriate foods will prevent occurrence in cats who have GI sensitivities. Routine annual veterinary check ups for adult cats will help identify early signs of more serious diseases associated with gastroenteritis.

Is Gastroenteritis Common in Cats?

Gastroenteritis is common, but specifically diagnosing it with a biopsy is much less so.

Typical Treatment

Symptomatic therapy includes: 

• Fasting (GI rest) • Bland diets • Antiemetics • Digestive protectants • Dewormers and antiprotozoals

• Probiotics • IV fluids • Antibiotics

Specific therapies target the underlying conditions and vary widely.

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