Introduction
Pancreatitis describes sterile pancreatic inflammation due to unregulated trypsin release within the pancreatic parenchyma. Chronic pancreatitis (CP) describes lym- phoplasmacytic inflammation and fibrosis of the pancreas, leading to progressive loss of pancreatic exocrine and endocrine function.
This differentiates it from truly acute pancreatitis where there is neutrophilic inflammation with varying amounts of pancreatic edema and necrosis, but the pancreas returns to normal functionally and histologically if the animal recovers from the acute bout. The definitions of acute and chronic pancreatitis are functional and histological rather than clinical, because some cases present acutely in spite of underlying chronic disease. The relationship between acute and chronic pancreatitis is a complex one involving an interaction between an animal's genetic make-up and environmental triggers. For a more detailed discussion see Watson (2015).The prevalence of CP in dogs and cats is difficult to estimate since most animals do not have histological confirmation of disease, however, it does appear to be a common disease in both species. Historically, CP was considered a relatively rare disease in dogs and more common in cats, but recent canine studies have confirmed its importance in this species also.
Most cases in cats and dog remain idiopathic. The causes of CP are poorly understood with possible triggers including high fat diets, hypertriglyceridemia, hypothyroidism, diabetes mellitus, hyperadrenocorticism, and certain drugs (azathioprine, potassium bromide, phenobarbitone; organophosphates, asparaginase, sulphonamides, zinc, clomipramine). It is important to recognize potential triggers of disease in susceptible dogs because these should be addressed during treatment and long-term management
Increased prevalence in certain breeds of dog such as cavalier King Charles spaniels (CKCS), Boxers, Collies and English Cocker Spaniels (ECS) suggest some genetic predispositions but these are likely to interact with environmental triggers and risk factors to produce disease.