Pancreatitis

See also Pancreas pathology

Signalment

• Yorkshire terriers, Labradors, Miniature Schnauzers and Miniature Poodles are predisposed
• Middle-old aged dogs
• Increased risk with obesity, diabetes mellitus, hyperadrenocorticalism, prior GIT disease or epilepsy (?treatment associated).
• Male and speyed females > intact females.

Description

Is due to the activation of digestive enzymes within the pancreas leading to autodigestion of the gland. Can be referred to as Acute or chronic pancreatitis.

• Acute Pancreatitis is rapid onset inflammation of the pancreas with little or no pathological changes occuring post recovery. This may completely resolve or 'wax and wane' into the future.
• Chronic Pancreatitis is continued inflammation leading to irreversible pathological changes (fibrosis, atrophy) and possible decreases in function.

The specific cause is usually idiopathic but several risk factors exist:

1. Nutritional: including obesity, low protein and high fat diets, feeding of ethionine, hypertriglyceridaemia and fatty meals.
2. Drugs and toxins: including L-asparginase, oestrogen, azathioprine, potassium bromide, furosemide, thiazide diuretics, salicylates, tetracyclines, sulphonamides, vinca alkaloids, zinc toxicosis, cholinesterase inhibitor insecticides, cholinergic agonist and hypercalcaemia.
3. Pancreatic Duct obstruction: caused by biliary calculi, sphincter spasm, duct wall oedema, duodenal wall oedema, neoplasia, parasites, trauma and iatrogenic reasons.
4. Duodenal juice reflux, Pancreatic trauma, ischaemia and reperfusion: including duodenal juice reflux into the pancreatic duct, surgical intervention, shock, anaemia, venous occlusion and hypotension.
5. Other: including parasitic (babesiosis), viral, mycoplasmal, end stage renal disease, liver disease and auto-immune diseases.

Cats mainly suffer from mild chronic interstitial pancreatitis.

Diagnosis

History and Clinical Signs

• History of eating a fatty meal
• Anorexia
• Vomiting
• Abdominal pain
• Lethargy
• Depression
• Nausea
• Diarrhoea (sometimes with blood, fresh or melaena, due to the proximity of inflamed pancreas to the duodenum and colon)
• More severe cases may present in shock, acute renal failure, jaundiced (due to focal hepatic necrosis), or with cardiac arrhythmias or pulmonary oedema or pleural effusions, widespread haemorrhage or DIC
• Acute haemorrhagic pancreatitis may present as shock and collapse.
• Cranial abdominal mass
• Mild ascites
• Dehydration (Mild to moderate)
• Febrile
• A cats presentation is more variable. If severe, they present with lethargy and anorexia with vomiting (35%) and abdominal pain (25%) being reported less than in the dog. Mild chronic pancreatitis may show anorexia and weight loss.

Diagnostic Imaging

Survey Radiography: Rarely helpful but findings may include:

1. In the right cranial abdomen:
   1. Increased density
   2. Decreased contrast
   3. Decreased granularity
2. Stomach displaced to left
3. Angle widened between pyloric antrum and proximal duodenum
4. Involving the Descending duodenum:
   1. Displacement to the right
   2. Prescence of a medial mass
   3. Gas pattern
   4. Thickened walls
5. Gastric distension
6. Delayed barium passage indicating abnormal peristalsis

However these findings are generally subjective so radiography is used to rule out differentials.

Abdominal Ultrasound: Highly specific with a sensitivity of 70% in dogs and 30% in cats. Findings include:

• Pancreatic enlargement
• Peritoneal effusion
• Hypoechogenic pancreas (pancreatic necrosis)
• Hyperechogenic surronding tissue
• Chronic pancreatitisand fibrosis may be hyperechogenic

Exploratory Laparotomy/Necropsy Findings

• The pancreas will be oedematous, soft with fibrinous attachments to surrounding organs
• Free fluid within the peritoneal cavity
• Pancreas liquefaction if severe enough
• Formation of pseudocysts
• Omental and pancreatic haemorrhages
• Areas of fat necrosis

References

Hall, E.J, Simpson, J.W. and Williams, D.A. (2005) BSAVA Manual of Canine and Feline Gastroenterology (2nd Edition) BSAVA

Merck & Co (2008) The Merck Veterinary Manual