“Liver Alone!” Everything You Needed to Know About Cats and Their Liver

Stuart Walton, BVSc (Hons), BSCAGr (Hons), MANZCVS (SAIM)

Dr. Walton is a clinical assistant professor in Small Animal Internal Medicine at University of Florida. He is a clinician of 20 plus years, receiving his veterinary degree at the University of Queensland. He has completed two internal medicine residencies at Veterinary Specialist Services (Australia) and Louisiana State University. Dr. Walton currently resides in Gainesville, Florida where he trains students, interns, and residents promoting common-sense veterinary medicine. He has a broad range of interests including infectious and inflammatory diseases, immune mediated disease, respiratory, urinary, gastrointestinal, and hepatic disease as well as extracorporeal blood purification techniques. He is the Co-Editor of Clinical Medicine of the Dog and Cat and has authored multiple articles and book chapters.

Overview:

A healthy liver is vital in cats as it has many vital roles. Of note, is that it is essential for the digestion of the food through the digestion of fat via the biliary system. Liver disease is common in cats with the most common diseases that occur being Cholangitis (inflammation of the bile ducts), cholangiohepatitis (inflammation of the bile ducts and the liver) and hepatic lipidosis. These three diseases account for up to 75% of all feline liver disorders treated. Cholangitis and cholangiohepatitis are necro-inflammatory liver disorders targeting the portal tract, often with a duct-centric orientation. Inflammation is from two sources;

1. An ascending bacterial infection, initiating from the pancreas or small intestine causing suppurative inflammation of the liver. This tends to respond positively to antibiotic therapy.

2. An immune-mediated disease causing non-suppurative inflammation. This disease process is usually treated with immunosuppressive therapy.

Both conditions, if left untreated, result in variable inflammation of the liver and biliary system and interference with bile flow which can cause significant damage to the liver. Definitive diagnosis is reliant upon obtaining a thorough history, performing a comprehensive physical exam, and clinicopathologic testing (e.g., CBC, serum chemistry, urinalysis). As well, more advanced ancillary diagnostics testing (bile acids, abdominal imaging, and biopsy) is essential in obtaining an accurate diagnosis. Liver biopsy ultimately enables differentiation between suppurative and non-suppurative disease, which is important for the successful treatment of disease.

Feline hepatic lipidosis is a potentially fatal intrahepatic cholestatic syndrome characterized by excess accumulation of fat in the liver. This metabolic syndrome is found in obese, middle-aged cats that undergo a period of acute anorexia (2 – 7 days duration) with catabolism. Although the underlying pathogenesis is not completely understood there is a general consensus that reduced caloric intake and protein-calorie malnutrition are important predisposing factors. Disease occurs as either a primary idiopathic disease syndrome or secondary to other diseases (e.g., pancreatitis, IBD, CKD, neoplasia, etc.). Cats usually present with inappetence, weight loss, and gastrointestinal signs (vomiting and diarrhea), as well as others. Diagnosis is made on the basis of clinical history, physical exam findings, clinicopathologic features, and abdominal ultrasound with concurrent liver aspirates. Regardless of the underlying cause, treatment aims are supportive, with IV fluid administration and nutritional therapy being paramount. During this lecture we will speak about the common causes of hepatic lipidosis, the up-to-date treatment choices that we have available to us in veterinary medicine through real world case examples.

Learning Objectives:

To get up to date information about the common causes of liver disease occurring in cats
To give a general overview of the diagnostic workup for liver disease in cats
To provide literature based up to date information to clinicians about the disease, treatment and outcome of disease for cats with Cholangitis/Cholangiohepatitis Syndrome

This course is RACE-approved for 1.0 continuing education credits hours in jurisdictions that accept RACE-approval.