• Inflammatory bowel disease (IBD) is a broad term for conditions that cause the lining of the digestive tract to become thickened and inflamed.
  • IBD can occur in dogs and cats.
  • Signs of IBD include chronic, intermittent vomiting and/or diarrhea, weight loss, and anorexia (appetite loss).
  • The exact cause of IBD is unknown.
  • Conclusive diagnosis of IBD requires biopsies (tissue samples) of the intestinal tract.
  • Some veterinarians may recommend a diet trial to test for food allergies.
  • Many pets with IBD require a special diet as well as medication.
  • Additional treatments may include antivomiting, antidiarrhea, and/or antiparasite medications, as well as antibiotics.
  • IBD usually can’t be cured, but it can frequently be controlled.

What Is Inflammatory Bowel Disease?

Inflammatory bowel disease (IBD) is a general term for conditions that cause the lining of the intestines to become thickened and inflamed. When this occurs, the digestive tract can’t absorb nutrients and move food substances properly. Certain portions of the digestive tract may be affected, or the entire length of the intestines may be involved.

What Are the Signs of Inflammatory Bowel Disease?

Dogs and cats with IBD can appear normal but may experience intermittent, but chronic, vomiting or diarrhea. The signs may vary, depending on what portion of the digestive tract is involved. Lesions at the beginning of the intestine may result in vomiting, while lesions further down the digestive tract may cause watery diarrhea or diarrhea with mucus or fresh blood. In more severe cases, the animal may lose weight, experience a loss of appetite, or have a thin, dull coat.

What Causes This Condition?

The exact cause of IBD is unknown. It is suspected that IBD is caused by chronic stimulation of the immune system from various factors, including dietary ingredients, parasites, or bacteria within the digestive tract. Genetics may also play a role.

How Is Inflammatory Bowel Disease Diagnosed?

Your veterinarian will probably recommend a number of tests to rule out other causes of vomiting and diarrhea, including fecal exams, blood tests, and radiographs (x-rays). An abdominal ultrasound may show thickened loops of bowel, which tends to occur with IBD. However, a definitive diagnosis of IBD requires biopsies (tissue samples) from the digestive tract.

Biopsies may be obtained during abdominal surgery, or via endoscopy using a fiberoptic endoscope. A fiberoptic endoscope is a long, narrow tube with a tiny camera at the tip. The endoscope can be inserted through the pet’s mouth to reach the esophagus, stomach, and small intestine, and/or inserted into the rectum to reach the large intestine. The instrument includes a small forceps, which the veterinarian can guide, using the camera, to take tissue samples.

While both procedures require anesthesia, endoscopy has the benefit of being less invasive, so the pet requires less time to recuperate. Endoscopy has some limitations, in that it may be difficult or impossible to reach some locations within the digestive tract, and only small samples may be obtained. For those reasons, surgery may be preferred.

Once a tissue sample is obtained, a specialist will examine the sample to determine the dominant type of cell found in the intestinal lining. This allows an exact diagnosis to be made, so treatment can be tailored to the specific type of IBD present.

What Is a Diet Trial?

In some cases, your veterinarian may suggest a hypoallergenic diet trial to rule out a dietary cause, such as an allergy. Although most pets with a food allergy develop problems with their skin (such as itching), some pets also develop signs consistent with IBD. In most cases of food allergy, the protein source in the food is usually the cause of the problem.

Before starting a diet trial, your veterinarian needs a full history of what diets your pet has eaten in the past. Be sure to include any human foods as well as any commercially prepared diets or treats. A diet trial usually involves feeding your pet a diet made using a protein source that your pet’s immune system has not been exposed to before, such as venison, rabbit, fish, or duck. This means your veterinarian needs to know what protein sources your pet has been eating, because those sources must be avoided for the duration of the diet trial. Another alternative is feeding a food that contains hydrolyzed protein, meaning that the protein has been broken down into very small molecules so that the immune system won’t recognize it.

During the trial, it is important that the pet eats only the hypoallergenic food and nothing else. All treats, edible chews (such as rawhide), and human foods must be discontinued. Feeding these items may expose the pet to the offending protein(s), which can confuse the results of the dietary trial. Typically, the animal is on the diet trial for a minimum of 12 to 16 weeks. If the signs improve or resolve during the trial and return when the pet is fed the previous diet, a diagnosis of food allergy can be assumed.

How Is This Condition Treated?

Treatment of IBD varies depending on your pet’s condition and the specific type of IBD determined by the biopsy. Most pets with IBD may require a special diet and/or anti-inflammatory or immunosuppressive medications.

Other recommendations may include antivomiting and antidiarrhea medications, antibiotics, parasite treatments, and/or probiotics.

Although IBD can’t always be cured, it can frequently be controlled. Pets with IBD may have occasional relapses.