Prevalence and underlying causes of histologic abnormalities in cats suspected to have chronic small bowel disease: 300 cases (2008-2013).

OBJECTIVE: To determine prevalence of histologic abnormalities in cats suspected, on the basis of compatible clinical signs and ultrasonographic findings, to have chronic small bowel disease; identify the most common underlying causes in affected cats; and compare methods for differentiating among the various causes of chronic small bowel disease. DESIGN: Retrospective case series. ANIMALS: 300 client-owned domestic cats suspected to have chronic small bowel disease. PROCEDURES: Medical records were reviewed to identify cats evaluated because of chronic vomiting, chronic small bowel diarrhea, or weight loss that also had ultrasonographic evidence of thickening of the small intestine. Cats were included in the study if full-thickness biopsy specimens had been obtained from ≥ 3 locations of the small intestine by means of laparotomy and biopsy specimens had been examined by means of histologic evaluation and, when necessary to obtain a diagnosis, immunohistochemical analysis and a PCR assay for antigen receptor rearrangement. RESULTS: Chronic small bowel disease was diagnosed in 288 of the 300 (96%) cats. The most common diagnoses were chronic enteritis (n = 150) and intestinal lymphoma (124). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that a high percentage of cats with clinical signs of chronic small bowel disease and ultrasonographic evidence of thickening of the small intestine had histologic abnormalities. Furthermore, full-thickness biopsy specimens were useful in differentiating between intestinal lymphoma and chronic enteritis, but such differentiation was not possible with ultrasonography or clinicopathologic testing alone.

Diagnosis of chronic small bowel disease in cats: 100 cases (2008-2012).

OBJECTIVE: To determine whether a diagnosis of chronic small bowel disease could be established in a subset of cats that had clinical signs of chronic vomiting, chronic small bowel diarrhea, weight loss, or a combination of these, combined with ultrasonographically determined thickening of the small bowel. DESIGN: Retrospective case series. ANIMALS: 100 client-owned domestic cats. PROCEDURES: Medical records of cats with clinical signs of chronic vomiting, chronic small bowel diarrhea, weight loss, or a combination of these, combined with ultrasonographically determined small bowel thickening, that underwent laparotomy and multiple small bowel biopsies between 2008 and 2012 were examined. Biopsy specimens were submitted for histologic evaluation, immunohistochemical evaluation, and, when findings were ambiguous, PCR assay for antigen receptor rearrangement. RESULTS: Chronic small bowel disease was diagnosed in 99 of the 100 cats. The most common diagnoses were chronic enteritis and intestinal lymphoma. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that cats with clinical signs of chronic small bowel disease should undergo detailed diagnostic testing because they are likely to have clinically important, diagnosable, treatable disease. Clinical signs of small bowel disease, especially weight loss and chronic or recurrent vomiting, are extremely common in cats. These signs should not be considered a normal condition and should not be ignored, regardless of common explanations given by owners, and cats with these signs should undergo appropriate diagnostic testing.