Implications for diagnosis
As the largest EPI study to date, this survey offers valuable clinical information. There are always potential methodological
issues with survey studies, which may introduce bias depending on the response rate. However, the response rate in this case
doesn't seem to detract from the data's clinical relevance.
What we have learned is that EPI in cats is not as rare as we once thought it was. The clinical presentation deviates significantly
from the typical presentation in a dog. Weight loss is common in both dogs and cats and can be quite pronounced. However,
in cats diarrhea is not a consistent finding. The diarrhea also appears to be much less severe when present and often doesn't
have the characteristics we expect to see, such as large-volume, highly fluid and greasy stools. Polyphagia does occur in
some cats, but almost half the cats were reported to have a decreased appetite.
A variety of concurrent diseases were found, most of which are not surprising. In most cases, the etiology of EPI in cats
likely relates to chronic pancreatitis and easily explains the 11 percent of cats that were thought to have pancreatitis in
this study.1-4 In dogs it usually is related to pancreatic acinar atrophy, which may also be the cause of EPI in very young cats.4 With chronic pancreatitis you can also see the development of endocrine pancreatic insufficiency, such as diabetes. Hepatic
lipidosis has also been linked with pancreatitis. IBD was reported in 21 percent of the cats with EPI, which may well have
to do with what is termed triad disease or triaditis. In cats it has been shown that there is a statistical association between IBD, pancreatitis and cholangiohepatitis.
Implications for treatment
Treatment for EPI with pancreatic enzyme supplementation was successful in a large percentage of the cases. The cats with
EPI also had other issues that might have impacted management. Most of the cats had low cobalamin concentrations. It has been
previously shown that in cats with hypocobalaminemia, supplementation of parenteral cobalamin is often needed to resolve GI
signs (250 µg subcutaneously weekly for six weeks, then once monthly with periodic checks of serum concentration).
In addition, the presence of EPI may be associated with small intestinal dysbiosis (formerly termed small intestinal bacterial overgrowth). The low cobalamin and high folate concentrations would certainly point toward this diagnosis. If pancreatic enzyme supplementation
and cobalamin injection do not resolve signs, consideration should be given to antibiotic therapy. Dietary therapy is also
important to consider, although there are no studies that suggest which diets should be used.
This study does suggest that we should test fTLI concentration in cats with unexplained weight loss or chronic diarrhea, even
if the animals are very young. The presence of hypocobalaminemia should also increase the suspicion that EPI is present. EPI
should also be considered in those cats with diabetes that appear to have good glycemic control but consistent weight loss
In a cat with unexplained weight loss in which blood work, the thyroxine concentration, thoracic radiographs and abdominal
ultrasound do not establish a diagnosis, I would often perform endoscopy to determine if occult neoplasia or some form of
IBD were present. Based on this study, I will certainly measure fTLI, cobalamin and folate concentrations before pursuing
more expensive and invasive diagnostic procedures.
Anthony Carr, Dr. med. vet., DACVIM, is a professor of small animal clinical sciences at the Western College of Veterinary
Medicine in Saskatoon, Saskatchewan.
1. Steiner JM, Williams DA. Serum feline trypsin-like immunoreactivity in cats with exocrine pancreatic insufficiency. J Vet Intern Med 2000;14:627-629.
2. Kook PH, Zerbe P, Reusch CE. Exokrine Pankreasinsuffizienz bei der Katze [Exocrine pancreatic insufficiency in the cat]. Schweiz Arch Tierheilkd 2011;153:19-25.
3. Thompson KA, Parnell NK, Hohenhaus AE, et al. Feline exocrine pancreatic insufficiency: 16 cases (1992-2007). J Feline Med Surg 2009;11:935-940.
4. Steiner JM. Exocrine pancreatic insufficiency in the cat. Top Companion Anim Med 2012;27:113-116.
5. Xenoulis PG, Wooff P, Zoran DL, et al. Feline exocrine pancreatic insufficiency: 150 cases. J Vet Intern Med 2012;26:765.