Veterinary Medicine: Hepatobiliary & Pancreatic Diseases

Hepatobiliary and Pancreatic Diseases

• This presentation covers hepatobiliary (liver, gall bladder, bile ducts) and pancreatic diseases in animals.
• The speaker, Prof Kamalan Jeevaratnam, is an expert in veterinary medicine.

Lecture Outcomes

• Students will understand the pathophysiology affecting the clinical presentation of these diseases.
• Students will be able to determine the necessary history and clinical examination for diagnosis.
• Students will gain knowledge of available diagnostic tools.
• Students will learn about principles of treatment and disease prognosis.

Clinical Signs and Presentation

• Clinical signs are often non-specific, typically gastrointestinal (GI) related, although neurological and haematopoietic abnormalities can also occur.
• Common signs include vomiting, diarrhoea (often pasty and discoloured), loss of appetite, polyuria/polydipsia (increased drinking and urination), weight loss (especially chronic), distended abdomen (often with ventral oedema), painful abdomen, lethargy, and abnormal behaviour.
• Specific signs might be noted in horses (e.g., photosensitization, colicy).

History and Physical Examination

• Signalment (species, breed, age) varies depending on the condition.
• History includes the time of onset, duration, previous diet, recent changes in behaviour, pesticide use, and exposure to the environment. Preventive healthcare history is also important.
• Physical examination is focused on mucous membranes and the abdominal area.
• Distended, painful abdomen can be a key sign along with other physical signs like palpable liver in smaller animals, lymph node enlargement (infection), bruising (clotting deficiency), yellowish discoloration, anaemia, and pyrexia.

Liver Function Tests

• Many liver tests are not specific to the liver. Results must be interpreted considering the animal's history, clinical findings, and medications.
• Several factors, like type, severity, and duration of the disease, are important factors to note when evaluating liver function in the patient.
• Common tests include bilirubin, albumin, glucose, blood urea nitrogen, cholesterol, ammonia, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT), and sorbitol dehydrogenase (SDH).
• Bile acid stimulation tests are also used.
• Liver function tests often indicate potential issues rather than definitive diagnoses.

Liver Enzyme Details

• ALT and AST are leakage enzymes, indicating hepatocellular injury and/or necrosis. ALT levels are usually higher than AST. Skeletal muscle is also a source of AST so elevations may not exclusively indicate liver damage.
• ALP levels are associated with biliary disease or drug-induced conditions and bone disorders.
• GGT levels are a useful indicator of biliary and hepatic disease, in particular impaired bile flow.
• Plasma half-lives for the various enzymes vary depending on the type of animal

Bile Acid Stimulation Test

• Bile acid levels are elevated with conditions like hepatocellular dysfunction or abnormal portal blood flow.
• Cholestasis (impaired bile flow) also leads to elevated bile acid levels. Horses lack a gall bladder, making bile acid measurement less consistent. Decreased feed intake for a period of days or longer can also lead to slightly elevated concentrations.

Other Relevant Biomarkers

• Trypsin-like immunoreactivity (TLI) is a marker of exocrine pancreatic insufficiency (EPI) if pancreatic exocrine secretory capacity is reduced below 10–15%
• Pancreatic lipase immunoreactivity (PLI) can be helpful in diagnosing pancreatitis.
• Cobalamin and folate are markers of metabolism in the distal and proximal intestinal absorption and are important in diagnosis.

Imaging

• Radiology/X-rays are used for assessing liver size, opacity, and displacement of the stomach in relation to the costal arch
• Ultrasounds distinguish between diffuse and focal hepatic diseases, identifying fibrosis, lipidosis, or possible neoplasia (cancer).

Treatment

• General options include fluid therapy to replace fluid losses and flush toxins.
• A diet with smaller, more frequent meals and a balance of carbohydrates and protein is generally recommended.
• Anti-inflammatory medications (steroids) and/or antibiotics may be necessary, although they might be contraindicated in some cases.
• Supplements, like Vitamin B, E, K, milk thistle, or zinc, might be beneficial.
• Lactulose can be used to reduce ammonia in patients.
• Other treatments include anti-emetics (to control vomiting) and anti-ulcers, depending on the animal's condition.

Hepatic Lipidosis

• Common in cats, especially those under stress or with concurrent diseases.
• Key features include anorexia, weight loss, and increased serum liver enzyme activities and associated metabolic pathways.
• Diagnosis involves clinical history, physical examination, clinical pathology, radiography, ultrasound, and biopsy.

Exocrine Pancreatic Insufficiency

• Insufficient digestive enzyme production causes inadequate nutrient digestion.
• Characterized by gradual or rapid onset of symptoms, including weight loss, diarrhoea, increased fecal volume, steatorrhoea (fatty stools), coprophagy (eating feces), and poor coat condition.
• Diagnoses rely on clinical history, physical signs, laboratory tests, including imaging.
• Treatment includes enzyme replacement, dietary modification, vitamin supplementation, antibiotics, and glucocorticoid therapy.

Portosystemic Shunt

• Congenital vascular anomalies bypass the liver.
• Symptoms can vary, including hepatic encephalopathy and failure to thrive.
• Often, diagnosis depends on clinical history and signs. Medical or surgical management are considered depending on individual circumstances.

Feline Inflammatory Liver Diseases

• Cholangitis or cholangiohepatitis are common primary liver diseases in cats.
• The disorders are classified by inflammatory cell types — in particular, neutrophilic or lymphocytic cholangitis and inflammatory disruption of hepatic parenchyma can signify extensions of primary cholangitis.
• In some cases, other concurrent diseases, such as inflammatory bowel disease, can be present, leading to diagnosis needing to rule out concurrent issues as well.

Triaditis Syndrome

• Suggests concurrent cholangitis, pancreatitis, and inflammatory bowel disease, a condition unique to cat's ductal anatomy.
• Diagnoses need multiple biopsy samples, and testing should include analysis for each condition.
• Treatment focuses on treating each condition individually.

Liver Disease Diagnostic Algorithms

• Various algorithms exist to determine if a cat has pancreatitis, frequently involving serum fPL levels.

References

• The presented material included references to various veterinary resources including BSAVA, Schaer and Gaschen, and eClinPath.