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Today's Ve T erinary Prac T ice | s eptember/ o ctober 2016 | tvpjournal.com TH e ye LL o W ca T: dia G nos T ic & TH era P e UT ic s T ra T e G ies Peer r eviewed 46 and culture, since bile has been shown to be the sample most likely to yield an informative bacterial culture result. 14,15 l iver biopsy is required for a definitive diagnosis of hepatic disease. 16 The most common infectious organisms found in patients with neutrophilic cholangitis are enteric bacteria (eg, E coli, Enterobacter, Clostridia) and antibiotics for treatment should be selected based on sensitivity. POSTHEPATIC HYPERBILIRUBINEMIA DIAGNOSTICS Extrahepatic Bile Duct Obstruction Abdominal ultrasound of cats with EHBO frequently identifies distension of the gallbladder, common bile duct, and intrahepatic ducts (Figure 5). Triaditis Diagnosis of triaditis is based on identification of disease in each of the 3 tissues involved; the gold standard for diagnosis is histopathology. l ess invasive diagnostics include the feline pancreatic lipase immu - noreactivity (fP l I) blood test, abdominal ultrasound, liver FNA, cholecystocentesis, cytology, culture and sensitivity, and small intestinal endoscopic biopsy; however, these patients may have increased anesthetic risks. Although not widely available in private practice, feline abdominal laparoscopy can be performed with equipment sized for pediatrics and allows the collection of tissue for histopathology (liver and pancreas) as well as direct aspiration of the gallbladder (Figure 6). Liver Fluke l iver fluke eggs can sometimes be found in the feces or by bile cytology. A recent study assessing the use of percutaneous ultrasound-guided cholecystocentesis in cats known to be infected with Platynosomum species flukes found the technique to be technically feasible and safe in cats with cholangitis. 17 THERAPEUTIC APPROACH Detailed treatment protocols for specific differentials are beyond the scope of this article. However, some selected therapies are described. Hydration status, pain (buprenorphine, 0.01 mg/ kg sublingual Q 8 H), and vomiting (maropitant, 1 mg/kg SC Q 24 H) can all be addressed in a relatively effective manner and can significantly impact the clinical outcome. Ursodeoxycholic acid (5−15 mg/kg Q 24 H) is an adjunct therapy that has been used in the successful treatment of bilirubin cholelithiasis, EHBO, and a Somali cat with PK deficiency, but it should not be used in place of antibiotics or prednisolone for lymphocytic cholangitis and neutrophilic cholangitis, respectively. 18 Adjunct therapy may include S-adenosyl- methionine (90 mg/cat Q 24 H), silimarin (2−5 mg/kg Q 24 H), and/or vitamin E (50 IU Q 24 H); however, there may be a limit to the number of medications an owner can administer to a cat. Selected Prehepatic Hyperbilirubinemia Treatment Options Immune-Mediated Hemolytic Anemia In addition to supportive care, including blood products, cats with IMHA appeared to respond Figure 6. Laparoscopic-assisted aspiration of the gallbladder in an icteric cat. Figure 5. Abdominal ultrasound demonstrating a distended gallbladder and enlarged biliary outflow tract in a cat with EHBO.