Characterization of Chronic Pancreatitis in English Cocker Spaniels

Abstract

Chronic pancreatitis (CP) is common in dogs. The cause is unknown. In humans, different causes of pancreatitis have histologically distinct appearances. The histopathologic lesions in English Cocker Spaniels (ECS) with CP were noted to be histologically different than those of other breeds with CP. CP in ECS is distinct from CP in other breeds and is characterized by a duct destruction similar to what is observed in autoimmune CP of humans. Eight ECS and 9 other breeds with histologically confirmed CP recruited over an 8-year period and 50 postmortem control dogs with CP. Clinical, clinicopathological, and ultrasonographic findings were recorded. Histological sections were compared with a normal dog and 59 dogs of other breeds with CP. Immunohistochemistry using anti-CD3, anti-CD79a, and anti-cytokeratin antibodies was used to evaluate distribution and type of lymphocytic inflammation and appearance of pancreatic ducts. Four male and 4 female ECS presented at a mean age of 7.2 years. Clinical signs were similar in ECS and other breeds. The pancreas was enlarged and hypoechoic in 4 ECS and 2 controls. Histopathology was characterized by interlobular and periductular fibrosis and inflammation in ECS compared with intralobular disease in most other breeds. Immunohistochemistry identified prominent anti-CD3(+) lymphocytic infiltrates around venules and ducts and a marked absence of interlobular ducts in ECS compared with mixed T-cell infiltration and ductular hyperplasia in most other breeds with CP. CP in ECS is distinct from CP in other breeds and is notably duct destructive.