19 – Digestive 1

Question 1

What are the inflammatory issues we can see in the exocrine pancreas?

Answer 1

• Acute pancreatitis
• Chronic (recurrent) pancreatitis +/- triaditis (CATS)

Question 2

Exocrine pancreas

Answer 2

• 80-85% of pancreas
• Acinar cells produce digestive enzymes
  o Amylase
  o Lipase
  o Inactive precursors (proenzymes): Trypsinogen, chymotrypsinogen
• Ductal cells secrete bicarbonate-rich fluid

Question 3

Pancreatitis

Answer 3

• Premature activation of digestive enzymes (not in the duodenal lumen where it normally should occur)
• Leads to local damage and inflammation +/- systemic effects
• Acute or chronic (based on histological findings)

Question 4

What is seen with acute pancreatitis?

Answer 4

• Neutrophilic inflammation
• Edema: ‘white’ space
• Necrosis

Question 5

What is seen with chronic pancreatitis?

Answer 5

• Fibrosis: pink streaming fibrous tissue
• Acinar cell atrophy
• Lymphocytic inflammation

Question 6

Pancreatitis in dogs

Answer 6

• ACUTE pancreatis is most COMMON
  o History of large fatty meal or dietary indiscretion (ex. garbage or unusual treats)
  o Often see vomiting and cranial abdominal pain

Question 7

In dogs, pancreatitis is an important cause of extra-hepatic biliary obstruction

Answer 7

• Bile duct and pancreatic duct enter the duodenum at the major papilla (separately but in close proximation)
• Often leads to cholestasis
• *secondary liver injury can also be due to local inflammatory mediators released from the pancreas

Question 8

What are the common lab findings in a dog with pancreatitis?

Answer 8

• *elevated serum amylase and lipase
• Inflammatory leukogram (often)
  o Degenerative left shift=suspicion for necrotizing pancreatitis +/- peritonitis
• Cholestasis (often)
  o Elevated hepatic enzymes and bilirubin
  o Local inflammation, perihepatitis, ascending inflammation
• Electrolyte, acid-base and renal disturbances due to v/d and dehydration (often)
• Lipemia (sometimes)
• Hypocalcaemia (occasionally): fat saponification
• Hyperglycemia (occasionally): stress and/or transient DM

Question 9

Amylase and lipase: dogs

Answer 9

• Cytosolic enzymes
• Increases 3-5x of the URI =suggestive of pancreatitis
• Imperfect: low sensitivity/specificity
• Short half-life: concentrations change rapidly
• **DO NOT RULE IN OR OUT PANCREATITIS BASED ONLY ON THESES ENZYMES (need to correlate clinically)

Question 10

Why is amylase and lipase in dogs imperfect?

Answer 10

• Mild increases (usually <3x the URI) seen with
  o GI and liver disease (also produced there)
  o Decreased GFR from dehydration or renal disease (decreased renal clearance or inactivation)
• Levels may be normal in animals with ‘low grade’/chronic pancreatitis (‘false negative’)
• Rarely: marked increased in lipase with hepatic/pancreatic neoplasia

Question 11

What are some potential sequela of severe pancreatitis?

Answer 11

• Proinflammatory cytokines may cause widespread leukocyte recruitment and vascular endothelial damage
• Secondary organ injury (lung, kidneys): MODS
• Hemostatic abnormalities (DIC)
• Death

Question 12

Pancreatitis in cats

Answer 12

• more likely CHRONIC disease
• > 95% are idiopathic
• Clinical signs are non-specific (lethargy, anorexia)
• *Often concurrent inflammation of pancreas, liver and intestines: “feline triaditis”
  o Bile duct and pancreatic duct combine before entering duodenum
• Very difficult to diagnose

Question 13

Triaditis; multiorgan GI inflammation in cats

Answer 13

• Cholangitis, pancreatitis, inflammatory bowel disease (IBD)
• Non-specific and overlapping clinical signs and lab data
• Pathogenesis not fully understood
  o Specific feline anatomy
  o Bacterial translocation
  o Possible autoimmune component
• Diagnosis is often presumptive

Question 14

Why is pancreatitis in cats difficult to diagnose?

Answer 14

• Leukogram changes are inconsistent
• Amylase and lipase are NOT useful
• Hypocalcaemia (occasionally)
• Hyperbilirubinemia (often)

Question 15

Serum pancreatic lipase immunoreactivity

Answer 15

• Measures pancreas specific lipase ONLY
• Higher specificity and sensitivity
  o Less false positives with GI/renal disease
• SNAP and Spec cPL/fPL (quantatative)
  o Abnormal SNAP should be followed by quantitative test

Question 16

What is a word of caution with the serum pancreatic lipase immunoreactivity?

Answer 16

• Many GI/abnormal conditions (acute gastroenteritis, foreign body, peritonitis) are associated with mild pancreatic inflammation, which may INCREASE serum PLI
  o Important to consider these other conditions in ill patients
  o Repeat measurement of serum PLI may help to differentiate primary from secondary pancreatitis

Question 17

Canine cPLI study

Answer 17

• Overlap in animals with mild pancreatitis (below and above the line)
• Neoplasm: normal to abnormal values

Question 18

Ultrasound: pancreatitis testing

Answer 18

• Sensitive up to 70% (operator dependent)
• Part of the ‘minimum database’ in cats? (talk about adding it)

Question 19

Cytology: pancreatitis testing

Answer 19

• Diagnostic in ~73% of acute pancreatitis cases (dogs) and 67% chronic pancreatitis cases (cats)
• Very low complication rate

Question 20

Mild pancreatitis and treatment

Answer 20

• Often treated symptomatically without diagnostic testing

Question 21

What are the non-inflammatory issues we can see in the exocrine pancreas?

Answer 21

• Exocrine pancreatic insufficiency (EPI)
• Pancreatic neoplasia

Question 22

Exocrine pancreatic insufficiency (EPI)

Answer 22

• Inadequate secretion of digestive enzymes
• Loss of >90% functional reserve leads to clinical signs (maldigestion)
  o Copious, “extra-malodorous” stool +/- diarrhea
  o May glisten or have a fatty appearance
  o Weight loss
• May be inherited: pancreatic acinar atrophy (German shepherds, rough collies)
• May be secondary to chronic pancreatitis/fibrosis
• Often leads to malabsorption

Question 23

Exocrine pancreatic insufficiency: CBC/chem panel

Answer 23

• Often unremarkable
• *hypocholesterolemia (occasionally)

Question 24

How is exocrine pancreatic insufficiency diagnosed?

Answer 24

• Measuring SERUM TLI (trypsin-like immunoreactivity)
  o Measures trypsinogen, trypsin, bound trypsin
  o An indicator of exocrine pancreatic enzyme production
  o *If decreased in value, then supportive of EPI
• Don’t measure serum lipase: as it is produced in other organs as well

Question 25

Pancreatic neoplasia

Answer 25

- Uncommon - Clinical signs: non-specific and overlap with pancreatitis o Lethargy, anorexia, GI signs - Majority have metastasized at time of diagnosis o GRAVE prognosis, very SHORT survival time - No specific lab abnormalities o May have elevated amylase/lipase, spec cPL/fPL - Diagnosed via cytology, histology, necropsy