Pancreatic Insufficiency Diagnosis

Exocrine pancreatic insufficiency (EPI), a heritable condition, results from autoimmune destruction of pancreatic acinar cells and is most common in young-adult German shepherd dogs (GSDs) and rough-coated collies (RCCs). Signs include polyphagia, weight loss, and soft voluminous feces. Diagnosis is based on signs, serum trypsin-like immunoreactivity (TLI) below reference range, and resolution with pancreatic enzyme supplementation. This study documented 3 cases in which EPI signs were present but serum TLI was normal. Case 1 was an intact male GSD (6 months of age), case 2 was an intact male RCC (5 months of age), and case 3 was an intact male GSD (18 months of age). Each had chronic soft feces or diarrhea, polyphagia with marginal weight gain, and chronic intestinal parasitism unresponsive to appropriate treatment. All had complete resolution when supplemented with pancreatic enzymes, and all had normal baseline serum TLI concentrations and low-normal serum pancreatic lipase immunoreactivity (cPLI). Serum TLI remained within range after a 12–20-month follow-up period during which none experienced progressive signs. Isolated enzyme deficiencies may have been present in these study dogs. Although rare, isolated pancreatic enzyme deficiency should be considered in young dogs with persistent, nonresponsive diarrhea suggestive of EPI but with serum TLI concentrations in the normal range.

CommentaryThis case report series exemplified that there are clinically relevant differences between cPLI and TLI levels. EPI diagnosis is often simple; however, there are cases in which EPI is suspected but the TLI result is not low enough to support the diagnosis. In cases in which EPI is suspected based on signs and breed predisposition but not confirmed by a low TLI result, a cPLI test should be submitted.—Dara Zerrenner, VMD, MS, DACVIM

SourceSuspected isolated pancreatic enzyme deficiencies in dogs. Viviano KR, Ziglioli V. JVIM 27:588-591, 2013.