Letter to Vetted: Unnecessary emphasis on hairballs for feline pancreatitis

I would like to address some of the statements about feline pancreatitis in this article (published as "That's No Hairball: Pancreatitis in Cats" in April 2016 Vetted).

Pancreatitis in cats can present in several ways, and, in many cases, does not involve vomiting. It can be seen coexistent with or secondary to other regional inflammatory diseases such as inflammatory bowel disease or hepatitis. Feline pancreatitis can also be challenging to diagnose. The feline pancreatic lipase immunoreactivity test is very sensitive and may not always reflect clinical pancreatitis.

Clinicians must always search for coexisting diseases-in many cases, treating the primary disease will result in resolution of the pancreatic inflammation. Because lactated Ringer's solution (LRS) does not cause lactic acidosis, LRS (often with added potassium) is usually an acceptable replacement fluid for intravenous therapy. Adding calcium to the fluids is rarely necessary, as hypocalcemia in cats with pancreatitis is extremely rare. Vitamin B12 deficiency results from intestinal dysfunction and would not be expected to be decreased in cats with pancreatitis unless they have concurrent gastrointestinal disease.

- Lee Schrader, DVM, DACVIM (small animal)

Elizabeth Colleran, DVM, DABVP (feline practice), responds:

It is a great community of veterinarians who are willing to take time to read and comment on feline medicine matters. The cover headline and article title focusing on hairballs may have been misleading regarding the incidence of vomiting.

Vomiting is not mentioned in the article as a clinical sign in cats, as anorexia, lethargy and diarrhea are more often seen. Many cats with pancreatitis have some other organ involvement. As cholangitis and hepatic lipidosis are often seen with pancreatitis, the use of lactated Ringer's solution must be based on ruling out forms of hepatopathy, which often manifest in elevations in alanine transaminase and alkaline phosphatase activities and bilirubin and cholesterol concentrations. Two studies report that 50%1 and 65%2 of cats, respectively, had cholangitis concurrent with histologic evidence of pancreatitis.

Also, a recent study showed hypocalcemia in 62.5% of cats with pancreatitis  and was associated with a poorer prognosis, which worsened in cats with a serum ionized calcium concentration of ≤ 1 mmol/L. Correction of this metabolic derangement appears to have significant importance.3 Low cobalamin concentrations can be a sign of pancreatic exocrine disease, because extrinsic factor is produced in the pancreas of cats and/or indicative of ileal disease (such as inflammatory bowel disease or lymphoma). Serum cobalamin concentrations should always be measured in such cases and, if found to be low, should be supplemented.

I sincerely appreciate the opportunity to share information on this subject as it may be significantly underdiagnosed in cats. The clinical signs are often vague and require a combination of history, clinical signs, a thorough work-up, an ultrasonographic examination and perhaps a tissue biopsy. Maybe we'll remember to place it on our rule-out list for cats with vague signs unlike those seen in dogs and people.

References

1. Callahan Clarke JE, Haddad JL, Brown DC, et al. Feline cholangitis: a necropsy study of 44 cats (1986–2008). J Feline Med Surg  2011;13:570-576.

2. Ferreri JA, Hardam E, Kimmel SE, et al. Clinical differentiation of acute necrotizing from chronic nonsuppurative pancreatitis in cats: 63 cases (1996-2001). J Am Vet Med Assoc 2003;223:469-474.

3. Dias C, Carreira LM. Serum ionised calcium as a prognostic risk factor in the clinical course of pancreatitis in cats. J Feline Med Surg 2015;17:984-990.

Editor's note: We apologize for the misleading headline for this article and are sorry for any confusion it may have caused.