Other minimally invasive tests that have been used to diagnose pancreatitis include assays for serum trypsin-like immunoreactivity (TLI) concentrations; serum, plasma, or urine trypsinogen activation peptide (TAP) concentrations; serum alpha-₁ proteinase inhibitor-trypsin complex concentrations; or serum alpha-macroglobulin concentrations. However, none of these tests have been shown to be both sensitive and specific for pancreatitis in dogs.^4,8,9 Serum TLI and TAP concentrations peak shortly after initiation of the disease and decline rapidly thereafter.¹⁰ So TLI or TAP concentrations may be normal by the time the patient is presented to a veterinary clinic.¹⁰

When stringent diagnostic criteria are applied, abdominal ultrasonography is highly specific for identifying pancreatitis and can be a valuable tool for diagnosing canine pancreatitis.¹ However, the sensitivity of abdominal ultrasonography for pancreatitis is low. In a recent retrospective study of 34 dogs with pancreatitis, only 23 dogs (68%) had ultrasonographic examination findings suggestive of pancreatitis.¹ Also, the use of abdominal ultrasonography requires special equipment and a high level of technical expertise. The reported 68% sensitivity was found when experienced ultrasonographers conducted the ultrasonographic examinations. To diagnose pancreatitis, stringent criteria must be met, and the presence of an enlarged pancreas or peripancreatic effusion is not sufficient for a diagnosis.¹¹ In cats, computed tomography has been shown to be inferior to ultrasonographic examinations in diagnosing pancreatitis, and in dogs, only preliminary data are available.^12,13 Furthermore, computed tomography's cost, anesthetic risks, and lack of availability preclude its usefulness in clinical practice.

Assays for measuring PLI in dogs have recently been developed and validated.^14,15 A cPLI concentration reference range of 2.2 to 102 µg/L was established in 74 healthy dogs, and a serum cPLI concentration of 200 µg/L has been suggested as a cut-off value for diagnosing pancreatic inflammation.¹⁶ This report details the clinical course of a dog with presumptive pancreatitis, based on clinical signs and ultrasonographic changes, in which serum cPLI concentrations paralleled the disease's clinical progression. In this case, we were able to compare the clinical, surgical, and abdominal ultrasonographic findings and serum cPLI concentrations in a dog with presumptive pancreatitis. The serum cPLI results supported the diagnosis of pancreatitis and coincided with the clinical signs, the visual assessment of the pancreas during surgery, and the abdominal ultrasonographic findings. Serum concentrations of cPLI were higher when the dog's clinical signs were severe and normalized as the clinical signs resolved.

Editors' note: Dr. Steiner is a paid consultant for Idexx Laboratories and is director of the Gastrointestinal Laboratory at Texas A&M University College of Veterinary Medicine.

Brandy Porterpan, DVM
Debra L. Zoran, DVM, MS, PhD, DACVIM
Jörg M. Steiner, med.vet., dr.med.vet., PhD, DACVIM, DECVIM-CA
Department of Small Animal Clinical Sciences
College of Veterinary Medicine and Biomedical Sciences
Texas A&M University
College Station, TX 77843

REFERENCES

1. Hess RS, Saunders HM, Van Winkle TJ, et al. Clinical, clinicopathologic, radiographic, and ultrasonographic abnormalities in dogs with fatal acute pancreatitis: 70 cases (1986-1995). J Am Vet Med Assoc 1998;213:665-670.

2. Saunders HM. Ultrasonography of the pancreas. Probl Vet Med 1991;3:583-603.

3. Steiner JM, Teague SR, Williams DA. Development and analytic validation of an enzyme-linked immunosorbent assay for the measurement of canine pancreatic lipase immunoreactivity in serum. Can J Vet Res 2003;67:175-182.

4. Steiner JM, Broussard J, Mansfield CS, et al. Serum canine pancreatic lipase immunoreactivity (cPLI) concentrations in dogs with spontaneous pancreatitis (abst). J Vet Intern Med 2001;15:274.