Chronic weight loss and diarrhea can be frustrating conditions to resolve in cats. There are many differential diagnoses to
consider, but new research suggests that one we should more closely examine is exocrine pancreatic insufficiency (EPI).
The diagnosis of EPI has become more common since the assay for feline trypsin-like immunoreactivity (fTLI) became available.
The test is considered diagnostic for EPI if a concentration of < 8 µg/L is found. Previously, making the diagnosis was more
complicated and based on clinical signs and several fecal digestion assays.
Researchers have published little information on EPI in cats—some individual case reports and three case series that reviewed
41 cases.1-3 The case series showed that weight loss was the most common clinical sign of EPI in cats. Diarrhea was common but not present
in all cats and often not like the typical feces noted in dogs (voluminous and malodorous with signs of steatorrhea). Polyphagia
was uncommon. Patients ranged in age from 3 months to 16 years, with most being middle-aged.
Although the cases in the series are interesting, they provide information on a small number of patients. Consider that in
2010, veterinarians submitted 775 samples to the Gastrointestinal Laboratory at Texas A&M University with fTLI concentrations
consistent with a diagnosis of feline EPI.4
Survey sheds new light
At the 2011 ACVIM Forum in New Orleans, researchers from the GI Laboratory and Department of Clinical Sciences at Texas A&M
presented an abstract outlining the results of a new EPI survey.5 The team searched its database over a 15-month period for cats with a TLI concentration below 8 µg/L. Questionnaires were
sent to the veterinarians who submitted the samples, and 150 surveys were returned.
Many breeds were affected by EPI, although the study could not definitively show that there is no clear breed predilection.
The affected cats' mean age was 8.1 years ± 4; 41 percent were females and 59 percent were males. Body condition was poor
with a median of 3/9. Of the cats with EPI that had their cobalamin concentrations measured, 77 percent were deficient, and
many had undetectable concentrations. In affected cats in which the folate concentration was tested, 47 percent showed an
The most common clinical sign in this study was weight loss, which was seen in 91 percent of the cats. The amount of weight
loss varied widely from 40 g (1.4 oz) to 6.82 kg (15 lb) with a median of 1.4 kg (3 lb). Loose stools were seen in only 62
percent of affected cats. Other clinical signs included poor haircoat (50 percent), anorexia (45 percent), increased appetite
(42 percent), depression (40 percent), watery diarrhea (28 percent) and vomiting (19 percent). Concurrent diseases were also
commonly reported (58 percent). The most common ones were inflammatory bowel disease (IBD, 21 percent), diabetes (14 percent),
pancreatitis (11 percent) and hepatic lipidosis (6 percent).
Of the cats affected with EPI, 68 percent were treated with pancreatic enzyme supplementation. Doctors saw a good response
in 66 percent of treated cats, a partial response in 24 percent and a poor response in 10 percent.