by: Jennifer Chang, DVM, DACVIM
Inflammatory bowel disease is one of the most common diseases causing gastrointestinal signs in dogs and cats. Patients often present with a history of vomiting, diarrhea and/or hyporexia that occur secondary to an inappropriate immune response within the intestinal tract. This immune response is most commonly triggered by dietary ingredients or infectious agents (i.e. bacterial, parasitic), but the underlying trigger may also be unknown. On baseline diagnostics, affected patients may exhibit hypoproteinemia and hypocholesterolemia. In patients with ileal involvement, hypocobalaminemia may also be present and can contribute to a mild anemia. Abdominal imaging often reveals thickened intestinal walls with or without loss of normal layering and mesenteric lymphadenopathy. An abdominal effusion may also be noted if significant hypoalbuminemia is present. Definitive diagnosis requires histopathologic evaluation of biopsies of the intestinal tract that can be collected endoscopically or surgically. As with other immune-mediated diseases, therapy for IBD is primarily through treatment of any underlying triggers and use of immunosuppressives. In cases with an infectious component, deworming or antibiotics may be needed. Patients with suspected dietary sensitivities may require a specialized diet, such as a low fat diet or a novel protein diet. Prednisone/prednisolone is often the initial immunosuppressive of choice for management of IBD. If control of the disease is not obtained within 1-2 weeks of initiating therapy, additional immunosuppressives, such as cyclosporine modified (Atopica®), should be utilized adjunctively. Patients with hypocobalaminemia will also benefit from subcutaneous cobalamin supplementation while the underlying disease is getting under control. Treatment is typically long term, but with time many patients can be slowly weaned to the lowest effective doses of the immunosuppressive medications, and some patients can eventually be managed with diet alone. A positive response to therapy is best noted with resolution/improvement in clinical signs and weight gain. In hypoproteinemic patients, serum albumin also serves as good marker to monitor for response to therapy. Unfortunately, IBD is rarely cured and relapses are possible, but with appropriate therapy, many patients can live a normal life span with a good quality of life.