Identifying and helping cats with inflammatory hepatobiliary disease - Veterinary Medicine
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Identifying and helping cats with inflammatory hepatobiliary disease
This common liver disease in cats can be acute or chronic and is caused by bacterial infections, liver fluke infestations, and many other conditions. These clinicians help you sort through the types and causes of this disease, so you can plot a course to the best outcome in affected cats.


VETERINARY MEDICINE


An association between nonsuppurative feline inflammatory hepatobiliary disease and chronic inflammatory disease involving the gastrointestinal tract and pancreas has been reported.8 In one study, 39% of cats with cholangiohepatitis had inflammatory bowel disease and mild pancreatitis.8 The term triaditis has been coined for the presence of these three disorders in a single patient. Other studies have noted an association between chronic pancreatitis and cholangitis.5,9 One explanation for this association is that nonsuppurative cholangitis may be one manifestation of a systemic autoimmune disorder. Alternatively, it has been suggested that chronic vomiting secondary to inflammatory bowel disease may increase intraduodenal pressure with subsequent reflux of gastrointestinal contents into the pancreatic duct.1 Since 80% of cats have only one pancreatic duct (which enters contiguously with the bile duct), duodenal reflux perfuses both the pancreatic and biliary systems. The result of this reflux is a low-grade bacteremia or inflammation that can lead to nonsuppurative cholangitis.1 How these disorders relate to one another is unclear at this time. Theories remain largely speculative, and the exact cause of nonsuppurative cholangitis remains elusive.

Lymphocytic cholangitis may represent a lymphoproliferative or neoplastic condition.1 A rare form of primary hepatic lymphosarcoma has been described in people in which small lymphocytes are the predominant cell type.1 It remains to be determined whether some cats with lymphocytic cholangitis have a similar syndrome.

Clinical examination findings. Cats with the lymphocytic or lymphocytic-plasmacytic form present with similar clinical signs.1,2 Most cats are middle-aged or older. But in one study, 14 of 21 cats with progressive lymphocytic cholangitis were less than 4 years of age.10 There is no sex predisposition.1 Commonly, cats have been ill for more than two months, often with a waxing and waning course of clinical illness. Signs are subtle and may include vomiting, diarrhea, weight loss, and, rarely, anorexia and lethargy.1,2 Some cats may have surprisingly good appetites and appear clinically like cats with hyperthyroidism.1

On physical examination, most cats have hepatomegaly and may be jaundiced.1,2 With the exception of one report, cats rarely present with ascites.10 Cats may develop a fat malabsorption that leads to a vitamin K deficiency and, rarely, to steatorrhea. They may have acholic stools due to decreased fecal bilirubin metabolism.1

Clinicopathologic features are fairly consistent among cats with lymphocytic-plasmacytic cholangitis or lymphocytic cholangitis. All have variable increases in serum liver enzyme activities, and some cats have hyperbilirubinemia. Cats with the lymphocytic variant may have a lymphocytosis and hyperglobulinemia.1,2,10

Chronic cholangitis secondary to liver fluke infestation

On histologic examination, liver biopsy samples from cats with chronic fluke infestation exhibit severe ectasia and hyperplasia of bile ducts and severe concentric periductal fibrosis.3,4 A mixed inflammatory infiltrate composed of macrophages, lymphocytes, plasma cells, and variable numbers of neutrophils and eosinophils is frequently present in portal areas.4 Eosinophils on a liver biopsy sample may be suggestive of liver fluke infestation because they are rarely seen in other types of feline inflammatory hepatobiliary disease.4 Concurrent periductal inflammation and edema and bile duct intraluminal neutrophilic exudates, adult flukes, and operculated eggs may be noted. 4


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Source: VETERINARY MEDICINE,
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