Differentiating feline inflammatory bowel disease from small cell gastrointestinal lymphoma requires biopsy but determines treatment and prognosis significantly. Getting the diagnosis right protects cat welfare.
The welfare stakes of accurate differentiation between IBD and small cell lymphoma are significant. A cat with lymphoma treated as IBD may experience temporary improvement from steroids followed by progressive disease as the lymphoma is not adequately controlled. A cat with IBD treated as lymphoma receives chlorambucil unnecessarily. The biopsy procedure involves anesthesia and is not without risk, but the welfare benefit of accurate diagnosis — enabling appropriate treatment for whichever condition is present — generally justifies the procedure for cats who are otherwise reasonable surgical candidates. Owners who understand the importance of biopsy versus response trial are better equipped to advocate for the diagnostic approach that best serves their cat's welfare.