Clinicians and researchers from Alamo Feline Health Center in San Antonio, TX retrospectively studied the medical records from 100 cats suspected to have chronic small bowel disease (CSBD) between 2008-2012. Inclusion criteria included a history of vomiting at least twice per month, small bowel diarrhea of several weeks’ duration, and/or weight loss of at least 0.5 kg (1 lb) within a 6 month period, or a combination of these criteria. Also, inclusion criteria required cats to have thicken small bowel (> 2.8 mm) in at least two locations as determined by ultrasonographic examination, and to have laparotomy with multiple small bowel biopsies examined histologically. If histologic results were ambiguous, immunohistochemistry and/or PCR assay for antigen receptor rearrangement were used to distinguish between enteritis and small-cell lymphoma.
Based on the above inclusion critieria, 99 of the 100 cats were determined to have CSBD. Chronic enteritis was diagnosed in 49 cats, with the predominate infiltrating inflammatory cells being lymphocytes and plasma cells (86%). Seventeen of these 49 cats had eosinophilic infiltration. Intestinal lymphoma was diagnosed in 46 cats and 44 of these cats had T-cell type lymphoma. Most likely T-cell origin was attributed to the inclusion criteria that selected for mucosal thickening and not for obstructive intestinal masses. Ultrasound examination and visualization of intestines during surgery suggested that CSBD is often segmental. Cats less than 8 years old were most likely to have enteritis, while older cats had enteritis or lymphoma. Concurrent biopsy specimens were obtained from small bowel, liver, and pancreas from 42 cats, 21 of which had enteritis. Eight of the 21 cats had concurrent hepatitis, two cats had concurrent pancreatitis, and only one cat had concurrent hepatitis and pancreatitis (triaditis).
The most important conclusion formed by the authors was that signs of CSBD, including ‘innocuous’ vomiting, should not be ignored or considered normal, regardless of the perception of the owner. Cats with these clinical signs should have an abdominal ultrasound performed to determine if the small bowel is thickened. The authors recommend laparotomy and collection of multiple small bowel biopsy specimens for cats with abnormal findings so that chronic enteritis or neoplasia can be definitively diagnosed and treated appropriately. [GO]