Can clinical signs, clinicopathological findings and abdominal ultrasonography predict the site of histopathological abnormalities of the alimentary tract in cats?

Objectives: Many cats with gastrointestinal signs have coexisting abnormalities in the intestine, liver and pancreas. Investigations typically involve clinicopathological tests, diagnostic imaging and biopsy, either at coeliotomy or by non-invasive means. While exploratory coeliotomy enables all organs to be sampled simultaneously, it is invasive and might not be necessary. The aim of the current study was to assess the performance of preliminary clinical information in predicting the histopathological presence of abnormalities in alimentary tract organs in cats.

Methods: The records of 38 cats with alimentary tract signs, which had ultimately undergone exploratory coeliotomy and surgical biopsy, were reviewed. The clinical signs, clinicopathological findings, diagnostic imaging findings and histopathology results were reviewed.

Results: On histopathological analysis, lesions were detected in 29/37 (78%) liver biopsies, in 29/35 (83%) gastrointestinal biopsies and in 17/37 (46%) pancreatic samples, the majority of which were inflammatory in nature. Clinical signs were generally poor markers of the presence of lesions in the alimentary tract. Further, while liver enzyme activity was relatively specific (88-100%) for detecting histopathological abnormalities in the liver, sensitivity was poor (11-50%). Pancreatic histopathological abnormalities were present in 1/3 of the cats with a positive pancreas-specific lipase result, and in 6/8 cats with a negative result. While relatively specific (57-100%) for both intestinal (57-100%) and hepatic (71-80%) histopathological abnormalities, abdominal ultrasonography lacked sensitivity for both organs (intestine 50-80%; liver 20-25%). In contrast, ultrasonography was relatively sensitive (50-80%), but not specific (17-22%) for detecting pancreatic lesions.

Conclusions and relevance: Clinical signs, and clinicopathological and ultrasonographic abnormalities lack precision for hepatic and pancreatic histopathological lesions in cats with alimentary tract signs, and cannot reliably predict from which organs biopsies should be collected. Arguably, therefore, exploratory coeliotomy is necessary to determine the site of histopathological abnormalities in feline alimentary tract disorders.