Gastroenteritis in Cats

Key takeaways

Gastroenteritis is a general term referring to inflammation of the stomach and intestines.

  • 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 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.
  • Blood work, diagnostic imaging, endoscopy, and biopsies are utilized to identify any underlying medical conditions.
  • Common therapeutic options include medication, hospitalization, surgery, and nutritional therapy.
Connect with a vet to get more information
Book an online vet

A closer look: Gastroenteritis in Cats

The stomach and intestines make up the lower section of the digestive tract. The stomach breaks food down into a predigested paste called chyme, which then proceeds through the intestines where the nutrients are extracted. When sections of the tract become inflamed, symptoms such as diarrhea and vomiting might develop. Prolonged symptoms of GI upset are referred to generally as gastroenteritis.

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.

Connect with a vet to get more information

With DVM, ICH certifications and great reviews by pet parents like you for this symptom

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.

Possible causes

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

Main symptoms

Some possible underlying causes of gastroenteritis are severe and potentially life-threatening, with a multitude of associated symptoms. Associated symptoms include

  • Excessive hairball production
  • Bloody vomit (hematemesis)
  • Bloody diarrhea (melena and hematochezia)
  • 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
  • Diagnostic imaging (x-rays and ultrasound)
  • Endoscopy
  • Biopsy

Additional diagnostics for more complicated cases depend on the specific underlying condition identified.

Steps to Recovery

Symptomatic treatment of gastroenteritis includes:

  • Fasting (GI rest)
  • Bland diets
  • Anti-vomiting medications
  • Digestive protectants
  • Dewormers and antiprotozoals
  • Probiotics
  • IV fluids
  • Antibiotics

Duration of symptoms varies 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, depending on the cause. 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. Some of the diseases that cause gastroenteritis have vaccinations available. Diligent storage of nonfood and inappropriate foods will prevent occurrence in cats who have GI sensitivities. Routine annual veterinary checkups for adult cats will help identify early signs of more serious diseases associated with gastroenteritis.

Is Gastroenteritis in Cats common?

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.


Alex Gallagher , - Writing for Merck Veterinary Manual
Alice Defarges , Shauna Blois , Edward J. Hall , Thomas W. G. Gibson , Kelly D. Mitchell. - Writing for Merck Veterinary Manual
Yuri Lawrence, Jonathan A. Lidbury - Writing for Today's Veterinary Practice

Our editorial committee

Our medical review team is responsible for validating and maintaining the quality of our medical information.