Pancreatitis in cats (Proceedings)

Only in the past decade has pancreatitis even been well-recognized in cats. In contrast to some other species, diagnosis of pancreatitis in cats is difficult, and there are few evidence-based recommendations for diagnosis and treatment. We will review some of the physiology and pathophysiology of the pancreas, and then discuss the diagnosis and management of pancreatitis in the cat. Pancreatitis involves autodigestion, and activation of zymogens. This occurs within the acinar cell, and involves fusion of zymogen granules with other vesicles.

Cats have two forms of pancreatitis

• Acute Necrotizing

o Can be mild (edematous) or severe (hemorrhagic)

o Severe cases can lead to multisystem failure, complications (pseudocyst or abscess)

• Chronic Nonsuppurative

o Can be subclinical

o Can lead to morphologic changes in the pancreas and eventual loss of exocrine or endocrine function

Causes of pancreatitis

• Nutritional Causes

o Low-protein, high-fat diets can induce

o Refeeding after prolonged malnutrition

• Hyperlipoproteinemia

o Cause or effect? Not documented in cats

o Related to abdominal fat necrosis associated with inflammation?

o Increased incidence of pancreatitis in human patients with familiar hyperlipoproteinemia

• Chemicals

o Elspar, azathioprine, 6-mercaptopurine, valproate

o Uncommon (in people) but maybe important in cats . . not studied!: ACE inhibitors, acetominophen, furosemide, sulfasalazine, thiazides

o Rare (in people): estrogens, tetracyclines, glucocorticoids

• Evidence for glucocorticoids is weak at best

• Cause elevation in lipase

• Hypercalcemia

• Scorpion stings (CCK)

• Orghanophosphates (CCK and Ach)

• Duodenal/biliary reflux

o Probably more important in cats than in other species

o Reflux normally does not occur, but bile duct and pancreatic duct are anatomically associated in cats.

o Antireflux mechanisms can fail due to increases in duodenal pressure (vomiting) or trauma to duodenum

• Pancreatic duct obstruction

o Experimental

o Tumors

o Parasites

o Inflammation and edema of the duct wall

• Associated with cholangiohepatitis and IBD in cats

• Surgical manipulation or duct obstruction

• Infectious

o Not documented in dogs and cats

o Increased incidence of pancreatitis in people with septic peritonitis

Diagnosis of pancreatitis in cats

Diagnosing pancreatitis is difficult in cats, because there are no sensitive or specific tests. In the cat, pancreatitis is commonly associated with other diseases. It can be associated with liver diseases, intestinal diseases, chronic renal disease, diabetes, and others. Cause and effect relationships are not clear.

• Chronic Pancreatitis

o Can be extremely difficult . . . vague clinical signs and laboratory changes

• Acute

o Dehydration 92%

o Tachypnea 74%

o Hypothermia 68%

o Icterus 64%

o Tachycardia 48%

o Abdominal pain 25%

o Abdominal mass 23%

o Ataxia 15%

o Fever 7%

• Lab results

o Normocytic normochromic anemia 55%

o Leukocytosis 30%

o Leukopenia 15%

o Hyperglycemia 64%

o Hypocalcemia 45%

o Hypokalemia 56%

o Hypoalbuminemia 24%

o Hyperbilirubinemia (64%)

o ALT 68%

o Alk Phos 50%

o TLI is neither sensitive nor specific

o Amylase/lipase not useful

o fPLI

• Forman et al., JVIM, 2004

• Sensitivity for pancreatitis is about 80%

• No difference in fPLI between cats with pancreatitis and healthy cats.

• Acute vs. Chronic

o Ferreri et al., JAVMA 2003

o 30 cats with histologically confirmed acute necrotizing pancreatitis

o 33 cats with chronic pancreatitis

o No differences in history, PE findings, clin path findings, radiography, or ultrasound

o ALT and AlkP were significantly higher in cats with chronic pancreatitis

• Diagnostic Imaging

o Ultrasound

• Hyperechoic pancreas, hyperechoic peripancreatic mesenteries (fat necrosis

• 80% sensitive in cats (Forman)

• Radiographs

o Signs consistent with regional peritonitis

o Ground glass, mass effect, trapped gas in duodenum

• 50% of cats have radiographic evidence of body compartment fluid

• Abdominocentesis

o Usually a non-septic exudate

• Treatment of Pancreatitis

o Remove cause if found

o Restore fluid deficits, perfuse pancreas

o Reduce pancreatic secretion ????????

o Pain management

o Manage complications

o Nutrition

o Fresh Frozen Plasma

• DIC develops as proteases activate kinin, fibrinolytic, complement, and coagulation cascades

• FFP is a source of anti-proteases, α-macroglobulins, albumin, coagulation factors

- Does FFP work?

• Rats with experimentally-induced acute pancreatitis

o Significant increase in 72-hour survival rates with CRI of plasma vs. colloid or crystalloid

o IP lavage with FFP also helpful in rats

• Human Studies

o Patients receiving 2 U FFP BID x 3 days vs colloid showed increases in α-macroglubulin, but no effect on clinical outcome

o Patients receiving 8 U/day x 3 days vs colloid also showed no effect (20% of FFP patients died, 18% of colloid patients died).

• No benefit shown in dogs or cats

- Albumin

• Oncotic properties help maintain circulatory volume

• Prevents pancreatic ischemia and edema

• Bind FFA (formed by PLA2) – FFA's can disrupt cell membranes

o Antibiotic Therapy is questionable

o Feeding Pancreatitis

(Br J Surg. 2000 Jun;87(6):695-707)

• Solid evidence that nutrition is important in acute pancreatitis to prevent malnutrition

• Parenteral feeding is safe and effective

• Enteral feeding is better than parenteral feeding

• Not always tolerated because of vomiting and inappetance

• Necessary in cats because of the common association with hepatic lipidosis

• Indications for Surgery

o Failure to respond to medical therapy

o Presence of pancreatic abscess or mass

• Based on repeated ultrasonography

o Severe icterus due to hepatobiliary obstruction

o Based on ultrasonography

o Consider if medical treatment fails to lower bilirubin

o Severe pancreatitis and septic peritonitis

• Post-op Management

o Same as medical management

o Antibiotics

o Infectious (secondary) complications responsible for 80% of deaths in human pancreatitis

o Enrofloxacin penetrates well into pancreas

o Most broad-spectrum antibiotics are probably reasonable

o Pain management

o Opiates are indicated over NSAIDS

o Corticosteroids ?????

• Stabilize lysosomal membranes

• Reduce inflammation

• Could inhibit RES clearance of α-M-enzyme complexes

o Antacids or nasogastric suction

• Not proven beneficial

The prognosis for a cat with acute pancreatitis is guarded.