Exocrine Pancreatic Insufficiency (EPI) in a Cat

Resumo

Background: Feline exocrine pancreatic insufficiency (EPI) was historically considered an uncommon disease; however, its diagnosis has increased with the availability of serum feline trypsin-like immunoreactivity (fTLI) testing. The disorder is characterized by insufficient secretion of pancreatic digestive enzymes, resulting in maldigestion and malabsorption. Clinical manifestations are variable and nonspecific, commonly including chronic diarrhea, weight loss, polyphagia, and poor hair coat quality. This report aimed to describe the clinical findings, diagnostic investigation, therapeutic management, and clinical evolution of a cat diagnosed with exocrine pancreatic insufficiency.

Case: A 5-year-old spayed female mixed-breed cat weighing 4 kg was evaluated due to a 30-day history of progressive diarrhea. Initially, the feces were soft, evolving to watery diarrhea with yellowish coloration and increased fecal volume. The owner also reported progressive weight loss despite marked polyphagia, polydipsia, and deterioration of coat quality. Physical examination revealed normal physiological parameters, mild dehydration (6%), and body condition score of 4/9. A complete diagnostic investigation was performed, including complete blood count, serum biochemical analysis, abdominal ultrasonography, urinalysis, fecal parasitological examination, immunochromatographic testing for feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV), and polymerase chain reaction (PCR) testing for Tritrichomonas blagburni. The laboratory and imaging findings were nonspecific, revealing only mild biochemical alterations and no significant ultrasonographic abnormalities. Supportive treatment was instituted; however, diarrhea persisted. Due to the chronic gastrointestinal signs associated with weight loss and polyphagia, empirical pancreatic enzyme supplementation with pancreatin was initiated. Clinical improvement was observed within 15 days after treatment onset, characterized by reduction in fecal volume, normalization of fecal consistency, decreased polyphagia, and progressive improvement in coat quality and body condition. Subsequently, serum feline trypsin-like immunoreactivity was measured and revealed a concentration of 7 mcg/L (reference range: 12-82 mcg/L), confirming the diagnosis of exocrine pancreatic insufficiency. Long-term clinical follow-up demonstrated adequate disease control with continuous pancreatic enzyme supplementation, without recurrence of severe gastrointestinal signs.

Discussion: Exocrine pancreatic insufficiency in cats remained underdiagnosed for many years because of the nonspecific nature of its clinical manifestations and the overlap with other chronic gastrointestinal disorders, especially chronic enteropathies and intestinal malabsorption syndromes. In the present report, chronic diarrhea associated with weight loss and polyphagia represented important clinical findings that supported the suspicion of EPI, although complementary diagnostic tests were initially inconclusive. Measurement of serum feline trypsin-like immunoreactivity remained the gold standard method for definitive diagnosis and was essential for confirmation of the disease in this patient. Furthermore, the favorable therapeutic response observed after pancreatic enzyme supplementation reinforced the diagnostic suspicion and highlighted the importance of early therapeutic intervention. The clinical evolution observed in this case demonstrated that pancreatin supplementation alone may provide satisfactory long-term control of clinical signs and significant improvement in quality of life in affected cats. Therefore, feline EPI should be included among the differential diagnoses in cats presenting chronic diarrhea, weight loss, and polyphagia, even when routine laboratory and imaging findings are nonspecific.

Keywords: diarrhea, cat, pancreas, pancreatin, feline trypsinogen.

Título: Insuficiência Pancreática Exócrina (IPE) em uma gata

Descritores: diarreia, gato, pâncreas, pancreatina, tripsinogênio felino.