Gastroenteritis in Cats

By Tammy Hunter, DVM; Ernest Ward, DVM

What is gastroenteritis?cat_gastrointestinal_2018-01

Gastroenteritis refers to inflammation of the gastrointestinal tract, meaning the stomach and the intestines. It can be caused by infection with bacteria, viruses, parasites, medications, or even new foods. The condition often causes abdominal pain, diarrhea, vomiting, and/or other clinical signs.

What are the symptoms of gastroenteritis?

Most cats with gastroenteritis will have intermittent episodes of vomiting and diarrhea. The vomit may contain foamy, yellowish bile, especially after the stomach has been emptied. Many owners will observe ’dry heaving’ or gagging after their cat eats or drinks. Large volumes of diarrhea will usually be produced several times a day. The diarrhea may have the consistency of soft- serve ice cream.

"Gastroenteritis is most often characterized by vomiting and diarrhea."

Many cats will exhibit tenderness when picked up around the abdomen or will resist handling of the stomach and hindquarters. Most cats affected with gastroenteritis will appear less active (lethargic), have a decreased appetite and they may hide. A low-grade fever is also common. Dehydration can occur quickly if the vomiting and diarrhea persist for more than 24 hours.

How is gastroenteritis diagnosed?

Gastroenteritis is a diagnosis of exclusion, which means that your veterinarian needs to eliminate or rule out other possible causes. The first step toward finding the cause of the vomiting, diarrhea, and lethargy is a good medical history.

Some key information in your cat’s medical history includes:

  • Your cat’s current diet, how often you feed your cat, and how much he or she eats.
  • Everything your cat ate or drank within the past 48 hours.
  • Any new foods, treats, or rewards.
  • Recent exposure to pesticides, medications, cleaning agents, or similar materials in your home environment.
  • Recent exposure to a new animal or person.
  • Previous episodes of vomiting and diarrhea (including their cause and treatment).
  • Any illness within the past month.
  • Any chronic illnesses that your cat may have.
  • Any medications, vitamins, or supplements given within the past month

Your veterinary health team may have you fill in a questionnaire prior to your visit. See handout “Diarrhea Questionnaire and Checklist for Cats” for an example.

After obtaining the medical history, your veterinarian will perform a thorough physical examination. Your veterinarian will look for evidence of dehydration, abdominal pain or tenderness, bloating or gas, swellings, and any other physical abnormality. Your cat’s temperature and other vital signs (heart rate and respiratory rate) will also be checked.

At this stage, your veterinarian may recommend diagnostic testing, which could include:

  • A complete blood cell count (CBC) - indicates the presence of dehydration, anemia, and infection.
  • Serum chemistries and electrolytes - detects organ system abnormalities and electrolyte imbalances caused by the vomiting and diarrhea.
  • A fecal test - detects intestinal parasites (e.g., roundworm, hookworm, giardia).
  • A urinalysis - detects urinary tract infections, kidney disease, dehydration, and diabetes.
  • Abdominal radiographs (X-rays) - searches for gastric (stomach) or intestinal obstruction and other abnormalities.
  • An abdominal ultrasound - searches for intestinal obstructions, certain cancers, or other abnormalities.

The severity and duration of your cat’s symptoms, his or her medical history, and the physical examination will determine which tests your veterinarian chooses to run.

What are some of the causes of gastroenteritis?

There are many causes of vomiting and diarrhea in cats. Some of the more common conditions that your veterinarian will attempt to rule out during the diagnostic work-up include:

  • infections (bacterial, viral, fungal, or parasitic)
  • foreign bodies (especially string or thread) or other objects
  • intussusception (the telescoping of the intestine into itself, causing an intestinal blockage)
  • tumors/cancers
  • poisoning/toxins (e.g., plants, cleaning agents)
  • endocrine diseases (e.g, diabetes, hyperthyroidism)
  • pancreatic, liver, or kidney disease

This is only a partial list of some of the more serious conditions that can cause vomiting and diarrhea in cats. Your veterinarian may discuss other possibilities based on your cat’s specific condition or history.

How is gastroenteritis treated?cat_iv

Once the results of the diagnostic tests are known and other causes of the clinical signs have been eliminated, your veterinarian will prescribe a treatment plan. The principal treatment of gastroenteritis consists of rehydration and the restoration of blood electrolyte balance (sodium, potassium, and/or chloride). Depending on the cat’s degree of dehydration, this fluid replacement may be given orally, subcutaneously (under the skin), or by intravenous (IV) treatment.

Medical treatment may also include:

  • Antibiotics (e.g., metronidazole, ampicillin) may be administered if the clinical signs are severe or if diagnostic tests suggest a bacterial infection.
  • Anti-emetic or anti-vomiting medications, for example maropitant (brand name Cerenia®) or metoclopramide (brand name Reglan®), may be given to your cat.
  • Gastrointestinal protectants, for example famotidine (brand name Pepcid®) or ranitidine (brand name Zantac®), may be used to prevent stomach ulcers .

Food may be withheld for 8-12 hours during the initial stages of treatment and then slowly be reintroduced via small, frequent feedings of a highly digestible, low fat diet. Your veterinarian will advise you on the best diet to feed your cat for a speedy recovery.

What is the prognosis (expected outcome) for gastroenteritis?

Most cases of acute gastroenteritis improve rapidly after rehydration. If the vomiting and diarrhea do not improve significantly within 24-48 hours of treatment, call your veterinarian.

Gastroenteritis is common in cats. Early recognition and treatment are the cornerstones to returning your cat to  her normal healthy state as quickly as possible.

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