Immune-mediated haemolytic anaemia (IMHA) is one of the most common immune-mediated diseases in the dog, and is associated with significant morbidity and mortality. Anecdotally, clinicians occasionally report signs consistent with pancreatitis in dogs with IMHA. It is unclear in these cases whether the inflammatory process associated with pancreatitis is a cause or consequence of IMHA. In man, there are several reports of pancreatitis in association with haemolytic anaemia, with proposed mechanisms including neutrophil activation, free radical formation, or microcirculatory disturbances. In dogs, pancreatitis has been reported as a complication of canine babesiosis and of zinc toxicity, both of which are also recognized as causes of haemolytic anaemia. The aim of this study was to investigate whether increased canine pancreatic lipase immunoreactivity (cPLI) concentration, as a marker of pancreatitis, is common in dogs with IMHA.

Records from the University of Bristol School of Veterinary Science were searched for cases of confirmed IMHA from which stored serum was available. Criteria for diagnosis of IMHA were a PCV <30% with one or more of spherocytosis, autoagglutination or a positive Coombs' test, and with no evidence of underlying disease on thoracic and abdominal radiographic and ultrasonographic imaging. Serum cPLI concentrations were assayed retrospectively by a commercially-available immunoassay (Spec cPLTM, Idexx Laboratories, Westbrook, ME). Data regarding signalment, previous use of steroids, haematology, biochemistry, Coombs' testing, treatment and outcome were collected from the clinical records.

Twelve dogs met the inclusion criteria. No dog had clinical evidence of pancreatitis on physical examination or abdominal imaging. Four dogs had increased serum cPLI concentrations (504, 553 748 and 797 μg/L, reference range <200 μg/L). Although numbers were too small for statistical analysis, there did not appear to be any association with breed, age, PCV, platelet count, hepatic enzyme activities or previous corticosteroid treatment. Ten dogs (including three of the four dogs with elevated cPLI concentrations) were still alive at the time of writing.

In conclusion, elevations in cPLI can be found in dogs with IMHA in the absence of any clinical suspicion of pancreatitis, suggesting that subclinical pancreatitis may be present in these patients. The pathogenetic mechanism responsible for this finding is unclear. This observation warrants further investigation in a prospective study.