Affects: Cats, Dogs
Pancreatitis is a common condition in cats and dogs. Pancreatitis is inflammation of the pancreas that can occur in two very different forms. Acute pancreatitis is sudden, while chronic pancreatitis is characterized by recurring or persistent form of pancreatic inflammation. Cases of both can be considered mild or severe. It is currently undecided whether chronic pancreatitis is a distinct disease or a form of acute pancreatitis. Other forms such as auto-immune and hereditary pancreatitis are presumed to occur but the existence of these forms has not been proven.
Pancreatitis occurs in approximately 0.8% of dogs and 0.6% of cats. Severe pancreatitis is often fatal.
Clinical Signs: Clinical symptoms of pancreatitis vary. Some animals will be asymptomatic or just have mild anorexia whilst others will have serious symptoms such as cardiac problems. Most symptoms are not directly caused by pancreatitis itself.
One study found the most common symptoms of pancreatitis in dogs to be: lethargy (88%), anorexia (86%), emesis (83%), and abdominal pain (59%).
Symptoms common in cats with pancreatitis include: anorexia (63–97%), dehydration (33–96%), lethargy (28–100%), emesis (35–76%), pallor (30%), icterus (16–24%), weight loss (20–61%), and diarrhoea (11–33%).
Symptoms of severe pancreatitis in cats includes: disseminated intravascular coagulation, pulmonary thromboembolism, cardiovascular shock, and organ failure. Pancreatitis is a common cause of disseminated intravascular coagulation and thromboembolism in the cat. Two studies found 26% of cats with disseminated intravascular coagulation and 11.8% with pulmonary thromboembolism had pancreatitis.
Acute pancreatitis can trigger a build-up of fluid, particularly in abdominal and thoracic (chest) areas, acute kidney injury, and cause inflammation in arteries and veins. The inflammation triggers the body's clotting factors, possibly depleting them to the point of spontaneous bleeding. This form can be fatal in animals and in humans. Severe acute pancreatitis also causes cardiovascular shock, disseminated intravascular coagulation, systemic inflammatory response syndrome, and organ failure. Dehydration is observed in nearly all dogs with severe acute pancreatitis.
Pathogenesis: The pathogenesis of pancreatitis is not well understood. Both genetic and environmental factors are involved in developing pancreatitis. In most acute pancreatitis cases there is premature activation and retention of zymogens of the acinar cells. These zymogens become pancreatic enzymes. Activated enzymes will get into the pancreatic tissue and later the peritoneal cavity and circulation. The effects of this include: interstitial oedema, necrosis of the acinar cells, haemorrhage, and necrosis of the peripancreatic fat; these trigger an inflammatory response from neutrophils and macrophages. The aetiology behind this disruption is unknown.
Pathophysiology: Pancreatitis is caused by autodigestion of the pancreas thought to begin with an increase in secretion of pancreatic enzymes in response to a stimulus, which can be any source from table scraps to getting into the garbage to drugs, toxins, and trauma. The digestive enzymes are released too quickly and begin acting on the pancreas instead of the food they normally digest. Once the process cascades, inflammatory mediators and free radicals are released and pancreatitis develops, causing amplification of the process.
Causes: The aetiology of pancreatitis in cats and dogs is unknown in the majority of cases. The amount of described causes for dogs is low and even lesser for cats. The causes of pancreatitis in humans is vastly different from that of cats and dogs. Two studies have suggested that hypertriglyceridaemia is a cause of pancreatitis in the Miniature Schnauzer; however, there is no evidence of this as a cause in other breeds. Another study has identified mutations of the SPINK1 gene in the Miniature Schnauzer as being associated with pancreatitis; however, another study found no association between SPINK1 mutations and pancreatitis, it instead demonstrated that the mutations were common amongst Schnauzers.
Iatrogenic pancreatitis is caused by certain drugs. The most common drugs that cause iatrogenic pancreatitis are potassium bromide, phenobarbital, L-asparaginase, azathioprine, and meglumine antimonate.
Diagnosis: Histopathological methods of diagnosis have been reported to diagnose up to 90% of clinically healthy dogs and 65% of cats with pancreatitis. Histopathology is not recommended for the diagnosis of pancreatitis on its own.
Complete blood count, serum biochemistry, and urinalysis are not helpful for diagnosing pancreatitis; however, they are useful to exclude differential diagnosis and confirm comorbidities.
Haemotological findings that can occur include: anaemia, leukopaenia, and thrombocytopaenia. These are not indicative of pancreatitis but instead symptoms of it.
Treatment: Due to the unknown aetiology treatment is supportive and based on what symptoms the animal shows. Underlying conditions such as infections, toxicity, and endocrinopathies, etc. should be treated.