Serum gamma-glutamyl transpeptidase activity in healthy cats and cats with induced hepatic disease

Activities of serum gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP), and alanine aminotransferase (ALT) were determined in healthy cats and in cats before and after treatment: common bile duct ligation, carbon tetrachloride administration, sham surgery, or anesthesia only. Significant (P less than 0.01) increases in serum GGT, ALP, and ALT occurred in cats with ligated bile ducts. Significant (P less than 0.01) increases in serum ALT occurred in carbon tetrachloride-treated cats. Increases of serum GGT, ALP, or ALT were not observed in cats subjected to sham surgery or anesthesia only compared with these cats' baseline values and values in healthy cats. Tissue GGT activity was measured in liver, renal cortex, jejunal mucosa, and bile ducts. There was a 1.5-fold increase in GGT activity in livers of cats with ligated bile ducts, compared with that in livers of healthy cats.     

Bile acid concentrations in the diagnosis of hepatobiliary disease in the cat

The clinical usefulness of measuring serum bile acid concentrations as a diagnostic test for hepatobiliary disease was examined in 80 cats that were suspected of having hepatic disease. Serum values of total bilirubin, alkaline phosphatase (ALP), alanine transaminase (ALT), and aspartate transaminase (AST) also were measured. Fasting serum bile acid values were determined by use of solid-phase radioimmunoassay for total conjugated bile acids or by a direct enzymatic spectrophotometric method. A definitive diagnosis was established by histologic examination of the liver, and on the basis of these findings, cats were assigned to groups (1 to 8, respectively) including: extrahepatic bile duct obstruction, hepatic lipidosis, cirrhosis, intrahepatic cholestasis (cholangiohepatitis, cholangitis), neoplasia, hepatic necrosis, portosystemic vascular anomalies, and miscellaneous. Cats in group 8 had no morphologic evidence of hepatobiliary disease or had hepatic lesions that were mild. Test efficacy of fasting serum bile acids, total bilirubin, ALP, ALT, and AST were expressed by use of 4 indices: sensitivity, specificity, positive predictive value, and negative predictive value. The diagnostic efficacy of fasting serum bile acids was examined alone and in combinations with the other tests. There was wide overlapping of values of fasting serum bile acids, total bilirubin, ALP, ALT, and AST among cats in groups 1 to 7. The specificity of fasting serum bile acids for the diagnosis of hepatic disease exceeded 90% at values greater than or equal to 5 mumol/L and reached 100% at greater than or equal to 15 mumol/L.(ABSTRACT TRUNCATED AT 250 WORDS)     

Choledochal cyst with secondary cholangitis,choledochitis, duodenal papillitis,and pancreatitis in a young domestic shorthair cat

Choledochal cysts, congenital segmental dilations of the common bile duct, have been reported in few cats, and histologic characterization is lacking. A 20-mo-old spayed female domestic shorthair cat was presented because of vomiting and weight loss. There was progressive elevation of liver enzyme activity (ALT > ALP, GGT) and hyperbilirubinemia. Diagnostic imaging identified focal cystic dilation of the common bile duct, dilation and tortuosity of adjacent hepatic ducts, and a prominent duodenal papilla. A choledochal cyst was suspected, and the animal was euthanized. On postmortem examination, there was a 2-cm, firm, thickened, cystic dilation of the common bile duct, patent with adjacent ducts. Histologically, the cyst wall was expanded by fibroblasts, collagen, and lymphoplasmacytic inflammation. Adjacent bile ducts were markedly dilated and tortuous, with lymphoplasmacytic inflammation and papillary mucosal hyperplasia that extended to the major duodenal papilla. There was chronic neutrophilic cholangitis, suggesting bacterial infection and/or disturbed bile drainage, extrahepatic obstruction, and lymphoplasmacytic pancreatitis with ductular metaplasia. Prominent lymphoid follicles within biliary ducts and duodenum suggested chronic antigenic stimulation. Choledochal cysts can be associated with chronic neutrophilic cholangitis, extrahepatic obstruction, choledochitis, duodenal papillitis, and pancreatitis, and should be a differential for increased hepatic enzymes and hyperbilirubinemia in young cats.     

Hematologic and biochemical abnormalities associated with induced extrahepatic bile duct obstruction in the cat

Bile duct obstruction was induced in 6 cats by surgical ligation and transection of the common bile duct. Clinical and laboratory changes were monitored weekly for 25 to 54 days. Clinical signs of obstruction were similar in all cats and included anorexia, pyrexia, lethargy, intermittent vomiting, weight loss, palpable gallbladder, hepatomegaly, and bleeding tendencies. Tissue jaundice and acholic feces were evident grossly as early as postsurgical day (PSD) 4 with a mean onset of jaundice at PSD 5.3 +/- 0.4. Hematologic changes were initially characterized by a mild neutrophilic leukocytosis that increased with the chronicity of bile duct obstruction. Regenerative anemia developed in 4 cats associated with gastrointestinal blood loss. Acute serum biochemical changes were characterized by a marked increase in the mean values of aspartate aminotransferase, alanine aminotransferase, total cholesterol, and copper. Comparatively, only moderate increases in mean serum alkaline phosphatase activity were observed. Mean total bilirubin values increased remarkably at postsurgical week (PSW) 1, reaching a maximal value of 23.1 +/- 4.4 mg/dl at PSW 3 with 71.6 +/- 2.7% direct bilirubin. With chronicity of bile duct obstruction ranging from PSW 3 to PSW 7, the mean serum values of aspartate aminotransferase, alanine aminotransferase, total cholesterol, serum alkaline phosphatase, and total and direct bilirubin stabilized and then declined, whereas the increased mean serum copper values persisted. At PSD 25 to 54, hepatic copper values and serum bile acids were markedly increased. Seemingly, clinicopathologic changes of induced cholestatic hepatic injury depended largely on the duration of biliary obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bile acid concentrations in the diagnosis of hepatobiliary disease in the dog

The clinical usefulness of measuring serum bile acid concentrations as a diagnostic test for hepatobiliary disease, was examined in 150 dogs that were suspected of having hepatic disease. Serum values of total bilirubin (TB), alkaline phosphatase (ALP), alanine transaminase (ALT), and albumin were also measured. Fasting serum bile acid (FSBA) values were determined, using a solid-phase radioimmunoassay for total conjugated bile acids or a direct enzymatic spectrophotometric method. A definitive diagnosis was established by histologic examination of the liver. On the basis of histologic findings, dogs were assigned to groups (1 to 8, respectively) including: extrahepatic bile duct obstruction, cirrhosis, portal systemic vascular anastomosis (PSVA), hepatic necrosis, intrahepatic cholestasis, steroid hepatopathy, neoplasia, and secondary disease. Dogs in group 8 had no morphologic evidence of hepatobiliary disease or had mild hepatic lesions. Test efficacies of FSBA, TB, ALP, ALT, and albumin were expressed using 4 indices: sensitivity, specificity, and positive-predictive and negative-predictive values. The diagnostic efficacy of FSBA was examined alone and in combinations with the other tests. There was wide overlapping of FSBA values among dogs in groups 1 to 7, and there was wide overlapping of ALT and ALP values among dogs in all groups. The specificity of FSBA for the diagnosis of liver disease exceeded 90% at values greater than or equal to 30 mumol/L and reached 100% at greater than or equal to 50 mumol/L. Individual liver tests with the best sensitivity for each group were:FSBA and ALP for extrahepatic bile duct obstruction; FSBA for cirrhosis and PSVA; ALT for hepatic necrosis; and ALP for intrahepatic cholestasis, steroid hepatopathy, and neoplasia. Combinations of tests with the best sensitivity for each group were: FSBA + ALP for extrahepatic bile duct obstruction; FSBA + ALT for cirrhosis and PSVA; FSBA + ALT and TB + ALT for hepatic necrosis; and FSBA + ALP for intrahepatic cholestasis, steroid hepatopathy, and neoplasia. Individual tests had the best sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)     

Diagnostic value of serum gamma-glutamyl transferase and alkaline phosphatase activities in hepatobiliary disease in the cat

The diagnostic value of serum gamma-glutamyl transferase (GGT) activity and serum alkaline phosphatase (ALP) activity in the detection of liver disease in the cat (n = 69) was compared. On the basis of histologic examination of the liver, cats were assigned to 8 groups: group 1--complete extrahepatic bile duct obstruction (n = 5), group 2--cholangiohepatitis-cholangitis syndrome (n = 11), group 3--hepatic lipidosis (n = 15), group 4--neoplasia, including lymphosarcoma and myeloproliferative disease (n = 9), group 5--hepatic necrosis (n = 7), group 6--cirrhosis (n = 3), group 7--portosystemic vascular anomaly (n = 4), and group 8--miscellaneous (n = 15). Cats assigned to group 8 lacked substantial histologic abnormalities of the liver. The mean value +/- SD of GGT in 20 clinically normal cats was 0.44 +/- 0.26 IU/L. The highest GGT activity in clinical patients developed in groups 1, 2, and 6. The highest ALP activity developed in groups 1 to 4. Significant correlations between GGT and ALP activities were detected only in groups 2 (P less than 0.001) and 5 (P less than 0.10). Among 54 cats with hepatic disease, only 11% had both the GGT and ALP activities within the normal ranges. Comparatively, 52% had ALP activities within the normal range, and 17% had GGT activities within the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)     

Liver glutathione concentrations in dogs and cats with naturally occurring liver disease

OBJECTIVE: To determine total glutathione (GSH) and glutathione disulfide (GSSG) concentrations in liver tissues from dogs and cats with spontaneous liver disease. SAMPLE POPULATION: Liver biopsy specimens from 63 dogs and 20 cats with liver disease and 12 healthy dogs and 15 healthy cats. PROCEDURE: GSH was measured by use of an enzymatic method; GSSG was measured after 2-vinylpyridine extraction of reduced GSH. Concentrations were expressed by use of wet liver weight and concentration of tissue protein and DNA. RESULTS: Disorders included necroinflammatory liver diseases (24 dogs, 10 cats), extrahepatic bile duct obstruction (8 dogs, 3 cats), vacuolar hepatopathy (16 dogs), hepatic lipidosis (4 cats), portosystemic vascular anomalies (15 dogs), and hepatic lymphosarcoma (3 cats). Significantly higher liver GSH and protein concentrations and a lower tissue DNA concentration and ratio of reduced GSH-to-GSSG were found in healthy cats, compared with healthy dogs. Of 63 dogs and 20 cats with liver disease, 22 and 14 had low liver concentrations of GSH (micromol) per gram of tissue; 10 and 10 had low liver concentrations of GSH (nmol) per milligram of tissue protein; and 26 and 18 had low liver concentrations of GSH (nmol) per microgram of tissue DNA, respectively. Low liver tissue concentrations of GSH were found in cats with necroinflammatory liver disease and hepatic lipidosis. Low liver concentrations of GSH per microgram of tissue DNA were found in dogs with necroinflammatory liver disease and cats with necroinflammatory liver disease, extrahepatic bile duct occlusion, and hepatic lipidosis. CONCLUSIONS AND CLINICAL RELEVANCE: Low GSH values are common in necroinflammatory liver disorders, extrahepatic bile duct occlusion, and feline hepatic lipidosis. Cats may have higher risk than dogs for low liver GSH concentrations.     

Duck circovirus induces a new pathogenetic characteristic,primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic, cholestatic liver disease of unknown cause. In the study, we found that duck circovirus (DuCV) induces PSC in natural and reproductive cases. PSC in DuCV naturally infected ducks was investigated by PCR and histopathology. A model of PSC was developed in one-day old duck by infection of DuCV. Effects on serum levels of liver enzymes and histology were evaluated, and DuCV tropism for bile duct in liver was analyzed by immuohistochemistry. Pathology observation of natural or reproductive DuCV infected ducks showed that the lesion of liver were characterized by cholangiocytic injuries and progressive fibrous obliteration of the biliary tree associated with lymphocytes infiltration. ALT, AST, ALP, GGT, ALB, TBIL and TP were significantly increased in serum of DuCV infected ducks. DuCV showed higher tropism for epithelial cells of bile duct than other cells in PSC.     

Biochemical evaluation of the hepatobiliary system in dogs and cats

The causes and clinical signs of hepatobiliary involvement in disease are many and varied and often are not referable directly to this organ system. Laboratory investigation frequently is necessary to rule hepatic disease in or out, to assess the functional impact on the liver, and to decide whether hepatic disease is the patient's primary problem or a complication of something else. The selection and interpretation of laboratory tests to resolve these problems is based on an understanding of relevant functional anatomy and pathophysiology. The mainstay of such assessment is hepatic enzymology, which can detect active disease in both hepatocytes and the biliary system. The hepatocellular pattern of disease is characterized by increases in leakage enzymes such as SDH, GLDH, and ALT and the cholestatic pattern by increases in induced enzymes (ALP and GGT). In general, enzymology does not allow the intensity or functional effect of hepatobiliary disease to be assessed, and quite severe hepatopathies may have only minimal enzyme abnormalities. For this reason, the primary biochemical data base for ruling hepatobiliary disease in or out always should involve some screening tests of hepatic function, such as albumin, protein, bilirubin, glucose, or urea determinations; as well as urinalysis to search for bilirubinuria and urobilinogenuria in hyperbilirubinemic patients and for ammonium biurate crystals when hyperammonemia or hepatic encephalopathy is suspected. Because the liver synthesizes most clotting factors, evaluation of blood coagulation is indicated when surgery is contemplated on patients with liver disease or when bleeding is present. Paired pre- and post-prandial determinations of serum bile acids are the preferred method for assessment of hepatobiliary function in dogs and cats. However, the BSP clearance test continues to be useful in the functional assessment of the liver as long as the dye remains available to veterinarians. Clearance of BSP is delayed in hepatocellular, cholestatic, and portosystemic disease as well as by severe extrahepatic circulatory disturbances, In general, this functional test is less sensitive than serum bile acids or the ammonia tolerance test in the recognition of hepatic encephalopathy caused by portosystemic anomalies. The objectives of biochemical screening of the liver are to establish the type (hepatocellular, biliary, or mixed), duration (acute, chronic), and stage (aggressive, convalescent) of hepatobiliary disease and to assess functional status.(ABSTRACT TRUNCATED AT 400 WORDS)     

ULTRASONOGRAPHIC FEATURES OF EXTRAHEPATIC BILIARY OBSTRUCTION IN 30 CATS

The goals of our study were to review the ultrasonographic features of spontaneous extrahepatic biliary obstruction in cats and to determine whether these features can assist in differentiating tumor, inflammation, and choleliths as the cause of obstruction. Thirty cats with a presurgical ultrasound examination an dconfirmed extrahepatic biliary obstruction were studied. A common bile duct diameter over 5 mm was present in 97% of the cats with extrahepatic biliary obstruction. Gallbladder dilation was seen in < 50% of the cats. Ultrasound identified all obstructive choleliths (calculus or plugs) in the common bile duct. However, neither common bile duct diameter nor appearance or any other ultrasonographic feature allowed differentiation between tumor and inflammation as the cause of obstruction. A short duration of clinical signs (10 days or less) seemed to be associated with obstructive cholelithiasis.     

Nonhematopoietic hepatic neoplasms in cats: 21 cases (1983-1988).

Nonhematopoietic hepatic neoplasms (n = 25) were diagnosed in 21 cats during a 5.5-year period. Thirteen of the neoplasms were benign bile duct adenomas and 12 were malignant, 6 of which were bile duct adenocarcinomas. All cats were greater than or equal to 10 years old, and 14 were male. Main clinical signs were anorexia and lethargy, and 15 of 21 cats had hepatomegaly. All 21 cats were feline leukemia virus-test negative. Although there was a trend toward high activities of serum alanine transaminase and aspartate transaminase, neither clinical signs nor enzyme activity were specific for diagnosis of hepatic neoplasia in the cats of this study.     

Evaluation of serum bile acid concentrations for the diagnosis of portosystemic venous anomalies in the dog and cat

The serum concentration of bile acids was measured in dogs and cats with portosystemic venous anomalies (PSVA). In 14 dogs, the mean serum bile acid concentration after 12 hours of fasting was 61.7 +/- 68.7 mumol/L (normal, 2.3 +/- 0.4 mumol/L (SEM) and when measured 2 hours after a meal in 15 dogs was 229.9 +/- 87.7 mumol/L (normal, 8.3 +/- 2.2 mumol/L). The fasting serum bile acid concentration was within the normal range in 5 of 14 dogs. The postprandial concentration was determined in 3 of the 5 and in each case increased more than tenfold above the fasting value. The mean fasting serum bile acid concentration in 4 cats was 24.4 +/- 10.1 mumol/L (normal, 1.7 +/- 0.3 mumol/L) and in 2 of the cats increased to a mean of 120.6 mumol/L (normal, 8.3 +/- 0.8 mumol/L) 2 hours after feeding. The bile acid values in patients with PSVA were correlated with values for blood ammonia content, sulfobromophthalein (BSP) retention, and results of conventional tests of hepatic function. Bile acid concentrations were more sensitive than abnormalities in serum enzyme activities or BSP retention and equal in sensitivity to the ammonia tolerance test in detecting hepatobiliary insufficiency. Bile acid measurements were accomplished with less inconvenience to the patient and clinician, than tests of BSP excretion or ammonia tolerance. Used in combination with conventional laboratory tests for hepatic disease, pre- and postprandial serum bile acid concentrations appear to be a sensitive and specific indicator of hepatobiliary dysfunction of value in the diagnosis of PSVA in the dog and cat.     

Observations on gamma-glutamyl transferase, 5'-nucleotidase and leucine aminopeptidase activities in the plasma of the horse

In 18 horses there was no effect of age or sex on plasma activities of gamma-glutamyl transferase (gamma-GT), 5'-nucleotidase (5'-NT) and leucine aminopeptidase (LAP). All the enzymes were equally stable after storage for one month at -20 degrees C and there was no significant difference between their activities in serum and plasma in clinically normal horses. The pattern of release of gamma-GT, 5'-NT and LAP into plasma was studied in 114 horses which had a variety of orthopaedic, gastrointestinal, cardiovascular and hepatic (necrosis, lipidosis, neoplasia and cirrhosis) conditions. A definitive diagnosis of hepatic disease was established by histological examination of the liver. gamma-GT and 5'-NT were leaked into plasma in hepatic disease and gamma-GT was the more sensitive indicator of liver damage. There was some evidence that gamma-GT and 5'-NT plasma activities may increase in hepatic necrosis as well as in biliary obstruction. LAP was insensitive and not hepatic specific in the horse.     

A morphologic and immunocytochemical study of hepatic neoplasms in cats.

A retrospective study was done of 47 neoplasms of the hepatic and biliary systems from 47 cats brought to The Animal Medical Center over a period of 10 years (1980 to 1989). Histologic examination of specimens taken at necropsy revealed that 87% (41/47) of the hepatic neoplasms were epithelial and 13% (6/47) were nonepithelial. Of the epithelial tumors, 25/47 (53%) were of intrahepatic bile duct origin, 9/47 (19%) were of hepatocellular origin, 5/47 (11%) involved the extrahepatic bile ducts, and 2/47 (4%) were adenocarcinomas of the gall bladder. Of the nonepithelial neoplasms, hemangiosarcomas were more common, 5/47 (11%), than leiomyosarcomas, 1/47 (2%). Multiple liver lobes were involved in 21/34 (62%) of the epithelial and all six of the nonepithelial intrahepatic neoplasms. Most of the bile duct adenocarcinomas (6/9) were predominantly characterized by acinar structures with mucin production, diffuse necrosis, and little desmoplasia. The hepatocellular carcinomas were characterized by three patterns-trabecular (five tumors), pseudoglandular pattern (two tumors), and anaplastic (one tumor). The hepatic carcinoid was characterized by various-sized groups of acinar and rosettelike structures, some with lumens, separated by thin fibrovascular stroma. The extrahepatic bile duct adenocarcinomas (4/4) were acinopapillary with moderate desmosplasia, whereas the adenocarcinomas of the gall bladder had elongated tubular structures lined by anaplastic cells and a severe desmoplastic reaction. The neuroendocrine carcinoma of the extrahepatic bile duct, the hemangiosarcomas, and the leiomyosarcoma had morphologic features characteristic of these neoplasms. Two of the 16 (13%) bile duct adenomas had anaplastic and precancerous changes. Residual benign components were seen in 10/15 (67%) of the biliary adenocarcinomas, 4/9 (44%) of the intrahepatic bile duct adenocarcinomas, and all of the extrahepatic bile duct adenocarcinomas and gall bladder adenocarcinomas. Results of immunohistochemical studies of the biliary neoplasms were similar to those described in studies of biliary neoplasms in human beings. Results of this study revealed that the frequency of different types of hepatic neoplasms in cats varied from that seen in dogs and human beings, but the morphologic features were comparable.     

A Retrospective Study of 77 Cats With Severe Hepatic Lipidosis: 1975–1990

The physical, clinicopathologic, and survival rates of 77 cats with severe spontaneous hepatic lipidosis are detailed in this report. Cats were subdivided into groups designated as idiopathic lipidosis if no other disease process was recognized, or secondary lipidosis if another disease process was diagnosed. Cats were also subdivided into groups designated as survivors or nonsurvivors on the basis of successful recuperation at 4 months after initial diagnosis. Differences between disease and survival groups were evaluated for significance. Overall, more female cats and middle-aged cats were affected. Presenting complaints of vomiting, anorexia, weakness, and weight loss were common. Physical assessment of most cats showed obvious hepatomegaly, jaundice, dehydration, and a weight loss ≥ 25% of usual body weight. Neurobehavioral signs indicative of hepatic encephalopathy, other than ptyalism and depression, were rare. Clinicopathologic features are characterized by hyperbilirubinemia and increased activities of serum ALT, AST, and ALP, with only small if any increase in γGT activity. Clinical features distinguishing cats with hepatic lipidosis from those with other serious cholestatic disorders include absence of hyperglobulinemia and low γGT activity relative to ALP activity. Although coagulation tests were abnormal in 45% of cats tested (n = 44), few cats showed clinical bleeding tendencies. Most cats received prophylactic vitamin K₁ therapy. Forty two cats received aggressive nutritional and supportive care and of these 55% survived. Cats with idiopathic disease were significantly younger, had significantly higher ALP activity and bilirubin concentration, and had a slightly better survival rate than cats with secondary lipidosis. Low PCV, hypokalemia, and an older age were significantly related to nonsurvival. Because of the variety of diets and food supplements used in case management, the influence of nutritional factors on survival could not be evaluated. (Journal of Veterinary Internal Medicine 1993; 7:349–359. Copyright © 1993 by the American College of Veterinary Internal Medicine.)     

Choledochotomy and primary repair of extrahepatic biliary duct rupture in seven dogs and two cats

Objective : To report clinical findings and outcome in dogs and cats undergoing choledochotomy or primary repair of extrahepatic biliary duct rupture. Methods : Retrospective study of dogs (n=7) and cats (n=2) that had choledochotomy or primary bile duct repair. Results : Extrahepatic biliary obstruction was confirmed at surgery in all cases. The underlying cause in four dogs and both cats was choledocholithiasis, two dogs had gall bladder mucocoeles with associated bile duct rupture, and one dog had inspissated bile obstructing the bile duct secondary to gall bladder carcinoid tumour. Three dogs and both cats had choledochotomies performed to relieve extrahepatic biliary obstruction, and four dogs with bile duct rupture underwent primary repair of the defect. One dog with a bile duct rupture was re‐explored four days postoperatively and had suffered dehiscence of the repair; this rupture was re‐repaired. All animals were discharged from the hospital, and did not have clinical recurrence of extrahepatic biliary obstruction. Clinical Significance : Choledochotomy and primary repair of extrahepatic biliary duct rupture were associated with low perioperative morbidity and no mortality in this small cohort of cases. These techniques are reasonable options either alone or in conjunction with other procedures when bile duct patency cannot be re‐established by catheterisation or bile duct discontinuity exists.     

Bacterial culture results from liver, gallbladder, or bile in 248 dogs and cats evaluated for hepatobiliary disease: 1998-2003

BACKGROUND: Information is lacking on the prevalence and susceptibility patterns of bacterial isolates in dogs and cats with suspected hepatobiliary disease. OBJECTIVES: To characterize the prevalence, identity, and antimicrobial susceptibility of common hepatobiliary isolates from such patients. ANIMALS: Dogs and cats presented to the University of Wisconsin-Madison Veterinary Medical Teaching Hospital for which samples of bile, gallbladder, or liver were submitted for culture from 1998 to 2003, including 190 dogs (192 culture episodes) and 58 cats (61 culture episodes). METHODS: Cases were identified from the microbiology laboratory database. Data from patient medical records were extracted, including the history of antimicrobial administration, the presence of fever, the results of CBC and serum biochemistry, the presence of biliary obstruction or hepatobiliary inflammation, and the results of aerobic and anaerobic bacterial cultures and aerobic antimicrobial susceptibilities. RESULTS: Biliary cultures yielded a significantly higher percentage of positive results overall (30% [18 of 60]) than did hepatic cultures (7% [15 of 215]). In patients with cholecystitis, 62% (8 of 13) had positive biliary cultures. In patients with hepatic inflammation, 23% (7 of 30) had positive bile cultures, whereas only 6% (6 of 103) had positive hepatic cultures. Escherichia coli, Enterococcus spp., Bacteroides spp., Streptococcus spp., and Clostridium spp. were the most common true-positive isolates. More than 80% of Enterobacteriaceae were susceptible to ciprofloxacin or aminoglycosides, with only 30-67% susceptible to first-generation aminopenicillins and cephalosporins. Liver samples obtained by surgery or laparoscopy were more likely to yield positive cultures than those obtained by percutaneous needle biopsy.     

Effects of long-term phenobarbital treatment on the liver in dogs

Long-term administration of phenobarbital has been reported to cause hepatic injury in dogs. Phenobarbital induces hepatic enzymes, and it may be difficult to distinguish the effect of enzyme induction on serum liver enzyme activities from actual hepatic damage. The hepatotoxicity of phenobarbital and the impact of enzyme induction on serum liver enzyme activity were investigated prospectively in 12 normal dogs. Phenobarbital was administered for 29 weeks at 5 mg per kilogram of body weight (range, 4.8— 6.6 mg/kg) PO q12h, resulting in therapeutic serum phenobarbital concentrations (20–40 μg/mL). Serum alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST), γ-glutamyltransferase (GGT), fasted bile acids (fBA), total bilirubin, and albumin were determined before and during treatment. Lateral abdominal radiographs, abdominal ultrasounds, and histopathologic examinations of liver tissue obtained by ultrasound-guided biopsy were performed before and during treatment. Radiographs revealed a moderate increase in liver size in most dogs. Ultrasonographic examination revealed no change in liver echogenicity or architecture. No evidence of morphologic liver damage was observed histopathologically. ALP and ALT increased significantly ( P < .05), GGT increased transiently, and albumin decreased transiently during the study. There were no significant changes in AST, bilirubin, and fBA. These results suggest that increases in serum ALP, ALT, and GGT may reflect enzyme induction rather than hepatic injury during phenobarbital treatment in dogs. Serum AST, fBA, and bilirubin, and ultrasonographic evaluation of the liver are not affected by the enzyme-inducing effect of phenobarbital and can therefore be helpful to assess liver disease in dogs treated with the drug.     

Pathogenesis and outcome of extrahepatic biliary obstruction in cats

Extrahepatic biliary obstruction (EHBO) was confirmed at surgery or necropsy in 22 cats. Biliary or pancreatic adenocarcinoma was diagnosed by histopathology in six cats and one cat had an undiagnosed mass in the common bile duct. The remaining 15 cats had at least one of a complex of inflammatory diseases including pancreatitis, cholangiohepatitis, cholelithiasis and cholecystitis. The most common clinical signs were jaundice, anorexia, lethargy, weight loss and vomiting. Hyperbilirubinaemia was present in all cases. Distension of the common bile duct and gall bladder was the most commonly observed finding on abdominal ultrasound. Nineteen cats underwent exploratory laparotomy for biliary decompression and diversion. Mortality in cats with underlying neoplasia was 100 per cent and, in those with non-neoplastic lesions, was 40 per cent. Long-term complications, in those that survived, included recurrence of cholangiohepatitis, chronic weight loss and recurrence of obstruction. Based on these findings, the prognosis for EHBO in cats must be considered guarded.     

Coagulation Abnormalities in 22 Cats with Naturally Occurring Liver Disease

Twenty-two cats with liver disease were evaluated for coagulation abnormalities including alterations in prothrombin time, activated partial thromboplastin time, thrombin time, factor VII activity, and platelet count. The purpose of the study was to determine the prevalence of coagulation abnormalities in this population of cats, classify abnormalities according to underlying pathogenesis, and determine if serum biochemical parameters typically used as indicatiors of liver disease showed any correlation with the coagulation abnormalities present. Study results indicated that at least 1 coagulation abnormality was present in 82% of the cats. Prolongation of prothrombin time was most common (16/22 cats) and factor VII activity was below reference range (<60%) in 15 cats. When classified according to underlying pathogenesis, vitamin K deficiency was the most common abnormality found (11/22). Other abnormalities were less common and included hepatic synthetic failure (3/22), indeterminate (3/22), and disseminated intravascular coagulation (1/22). Increase in alkaline phosphatase (ALP) activity was the only biochemical abnormality that showed statistically significant correlation with coagulation abnormalities ( P = .023). Cats with marked increases in ALP activity were more likely to have coagulation abnormalities than those with only mild increases in ALP activity.