Inflammatory Bowel Disease: Another Term & a More Logical Approach?

The term inflammatory bowel disease (IBD) in small animal gastroenterology can be problematic; often when it is used, there comes the need to explain that both the definition and treatment of the disease in dogs and cats are very different from those for IBD in humans. This review article suggests—and justifies (at least in dogs)—the use of the term chronic enteropathy as a replacement for IBD.

IBD in humans includes 2 different chronic disorders characterized by inflammation of the intestinal wall: Crohn’s disease and ulcerative colitis. These are not recognized in dogs; however, dogs do develop a chronic enteropathy (arbitrarily defined as >3 weeks’ duration) that is characterized by signs that can include vomiting, diarrhea, changes in appetite, and weight loss. 

The author justified the term chronic enteropathy for this clinical presentation using the following criteria:

• It can be used for animals in which intestinal inflammation is suspected but has not been documented (ie, no biopsies have been performed).
• It does not imply what treatment will be needed to control clinical signs.

Chronic enteropathy can only be diagnosed after exclusion of extraintestinal causes (eg, exocrine pancreatic insufficiency, hypoadrenocorticism), infectious and parasitic causes, and neoplasia. 

Supported by an extensive literature review, the author demonstrated that >50% of dogs with chronic enteropathy responded to dietary modification. A further subset responded to or improved with antibiotic therapy, and a small proportion required immunosuppressive treatment. The author labeled these as cases of food-responsive enteropathy, antibiotic-responsive enteropathy, and immunosuppressive-responsive enteropathy, respectively. Protein-losing enteropathy can overlie some of these conditions but may also respond to appropriate chronic enteropathy treatment; however, biopsy is recommended to confirm the diagnosis and rule out small cell lymphoma.

These data suggest an eminently logical and sequential approach (ie, dietary trial, antibiotic therapy, immunosuppressive drugs) to chronic enteropathy patients after specific causes of chronic diarrhea have been ruled out.

Note: Dr. Burrows is editor in chief of the Clinician’s Brief Global Edition.

Key pearls to put into practice:

After ruling out extraintestinal, infectious, and other causes of chronic diarrhea, a dietary trial should be started. This can be composed of either a novel antigen or a hydrolysed diet and should be used for a minimum of 4 weeks. It can be expected that ≥50% of dogs will respond within 2 weeks. Strict client compliance (ie, no treats, no protein-containing medications) is critical.

If diet alone is not successful, antibiotics (ie, oxytetracycline, metronidazole, tylosin, or enrofloxacin as appropriate for 4-6 weeks) should be initiated. Probiotic therapy and intestinal biopsy should be considered.

If a positive response is still not seen, immunosuppressive therapy is indicated using either prednisolone, azathioprine, budesonide, or, possibly, cyclosporine.