Kelly D. Mitchell, DVM, DVSc., DACVIM

Enteral feeding tubes are an essential tool in the provision of nutritional support to animals unable or unwilling to consume sufficient calories on their own. Nutritional support should be considered for any animal that has been anorexic or has had inadequate voluntary caloric intake for ? 3 days, has lost ? 10% of their body weight or has other signs of malnutrition (e.g. poor hair coat, muscle wasting, poor wound healing, hypoalbuminemia, lymphopenia).

The gallbladder is a small, pear-shaped organ located in the cranial abdomen between the right medial and quadrate liver lobes. Bile is synthesized by hepatocytes and collects within canaliculi and is sequentially drained from into bile ductules, interlobular, lobar and hepatic ducts.

Rational pharmacological management of canine and feline liver diseases is built around removal of the inciting cause, specific therapy (e.g. anti-inflammatory, antifibrotic or anticopper agents) and provision of general liver support. Generally speaking, treatment recommendations are based upon the suspected pathophysiology of the disease or extrapolated from the human medical literature and are not based on veterinary clinical trials.

Gastrointestinal (GI) (or alimentary) lymphoma is the most common form of lymphoma in cats. Feline GI lymphoma is histologically classified as low, intermediate or high grade according to the size and anaplasticity of the neoplastic lymphoid cells.

Disorders of the feline exocrine pancreas are common. Feline pancreatitis is classified as acute necrotizing, acute suppurative and chronic non-suppurative. Acute pancreatitis is characterized by inflammation of the pancreas that is completely reversible upon removal of the underlying cause, while chronic pancreatitis is characterised by irreversible histological lesions such as fibrosis and atrophy. Necrosis of pancreatic acinar cells and peripancretic fat with or without inflammation, hemorrhage, mineralization and fibrosis, describes acute necrotizing pancreatitis (ANP).

The basic anatomical structures of the esophagus are the upper esophageal sphincter (UES), the body of the esophagus and the lower esophageal sphincter (LES). The entire canine esophagus is composed of two layers of striated muscle, while the distal third of the feline esophagus is composed of striated muscle.

Elevations of in one or more serum liver enzyme activities (LEA) are a common finding on serum biochemical analysis. Liver enzyme measurements do not reflect liver function but rather hepatocyte membrane integrity, cholestasis and enzyme induction.