Concurrent hepatopathy in dogs with gallbladder mucocele: Prevalence, predictors, and impact on long-term outcome.

BACKGROUND: Information is limited regarding the prevalence and importance of hepatic histologic abnormalities in dogs with gallbladder mucocele (GBM). OBJECTIVES: To (a) report prevalence of hepatic histologic abnormalities in dogs with GBM (b) evaluate for association between hepatic abnormalities and outcome in dogs with GBM (c) evaluate whether neutrophil-to-lymphocyte ratio (NLR) differs in dogs with GBM with and without specific hepatic lesions. ANIMALS: Fifty-two dogs with grossly and histologically confirmed GBM. METHODS: Multicenter, retrospective study of dogs with GBM undergoing cholecystectomy with concurrent liver biopsy. Archived histological sections of gallbladder and liver evaluated by investigators blinded to data. Proportions of dogs with each histologic abnormality alive vs deceased at 1, 3, and 12 months post-cholecystectomy compared. Mann-Whitney U performed to determine if NLR differed in dogs with or without selected lesions. RESULTS: 51/52 (98%, 95% CI [89%, 99%]) dogs with GBM had at least 1 hepatic histologic abnormality. Hepatic fibrosis (37/51; 73%, 95% CI [59%, 83%]), biliary hyperplasia (29/52; 56%, 95% CI [42%, 68%]), and portal inflammation (25/52; 48%, 95% CI [35%, 61%]) were most common. The proportion of dogs alive vs dead differed based on the fibrosis score at 1, 3, and 12 (P ≤ .04) months post-cholecystectomy. Dogs with hepatic necrosis (P = .006) and cholangitis/cholangiohepatitis (P = .02) had higher NLRs compared to dogs without these lesions. CONCLUSIONS AND CLINICAL IMPORTANCE: Histologic abnormalities of the liver are common in dogs with GBM. A higher portal fibrosis score might be associated with shortened long-term survival after cholecystectomy for dogs with GBM. An increase in NLR might predict hepatic necrosis and cholangitis/cholangiohepatitis in dogs with GBM.

Fatal Wedelia glauca intoxication in calves following natural exposure.

A group of 342 beef calves, corralled in the Patagonia region of Argentina, were fed alfalfa hay that had been inadvertently contaminated with Wedelia glauca. A total of 147 (43%) calves died within 4 days. Pathologic findings in 2 calves were diffuse centrilobular hepatic necrosis and hemorrhage with edema in the gallbladder, common bile duct, and choledochoduodenal junction. Epidermal fragments of W. glauca were identified in rumen contents by microscopy. Intact W. glauca plants and leaf fragments were found in the hay. Patches of defoliated W. glauca were also identified in the alfalfa pasture from which the hay had been baled.

A multicenter retrospective study assessing progression of biliary sludge in dogs using ultrasonography.

BACKGROUND: Biliary sludge (BS) frequently is identified on ultrasonographic examination and is described as incidental. It is hypothesized that biliary stasis and hypersecretion play a role in both BS and gallbladder mucocele (GBM) formation. Recent studies have documented similarities in composition of BS and GBM, and there are several examples of progression from BS to GBM in the veterinary literature. OBJECTIVES: To assess the relationship between the presence of BS and later development of GBM in dogs, over time periods >12 months. ANIMALS: A total of 154 dogs with BS and ultrasonographic follow-up >12 months. METHODS: Medical records were retrospectively collected from 9 UK-based referral centers for all available time points. A semiobjective scoring system was used to track volume of BS within the gall bladder (GB) over time. RESULTS: Twenty dogs developed GBM during the study period. Shetland Sheepdogs (odds ratio [OR], 40.99; 95% confidence interval [CI], 3.61-465.95; P = .003) and Border Terriers (OR, 11.66; 95% CI, 3.28-46.63; P < .001) were independent risk factors for the development of GBM. Non-gravity-dependent BS (NDBS) was noted to form before GBM development in 9/20 dogs, and breeds at-risk for GBM were more likely to have NDBS. Odds for the development of GBM increased with BS score. CONCLUSIONS AND CLINICAL IMPORTANCE: Dogs with NDBS may be at risk for the development of GBM and a stratified BS scoring system could allow for semiobjective monitoring over time, particularly in at-risk breeds.

Evaluation and treatment of a posttraumatic intrahepatic biloma in a dog.

A 9 mo old male mixed-breed dog was presented with a history of chronic vomiting and fever after undergoing a cholecystectomy for the management of traumatic cystic duct rupture associated with biliary effusion 10 days before referral. A 6 cm × 6 cm intrahepatic bile collection, a biloma, was diagnosed on abdominal ultrasound and fine-needle aspiration. The biloma was treated with percutaneous catheter drainage under ultrasonographic guidance. Two years after aspiration, the dog continued to do well.

Reference limits for hepatic bile duct-to-arteriole and bile duct-to-portal tract ratios in healthy cats.

OBJECTIVE To establish reference limits for hepatic bile duct-to-arteriole ratio (BD:A) and bile duct-to-portal tract ratio (BD:PT) in healthy cats and assess whether these parameters could be used to support a diagnosis of biliary ductopenia in cats. SAMPLE Hepatic biopsy samples from healthy cats (n = 20) and cats with ductopenia (2). PROCEDURES Hepatic biopsy samples from healthy cats were used to count the number of bile ducts and hepatic arterioles in 20 portal tracts for each cat. Mean BD:A and mean BD:PT for each cat were calculated, and these values were used to determine reference limits for mean BD:A and mean BD:PT. Results of histologic evaluation, including immunohistochemical staining in some instances, were compared for healthy cats versus cats with ductopenia. RESULTS Of the 400 portal tracts from healthy cats, 382 (95.5%) and 396 (99.0%) had BD:A and BD:PT, respectively, ≥ 1.0, with less variability in BD:A. Mean BD:A and BD:PT were markedly lower in both cats with ductopenia, compared with values for healthy cats. However, only mean BD:A for cats with ductopenia was below the reference limit of 0.59. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that systematic evaluation of BD:A, with a lower reference limit of 0.59 to define biliary ductopenia in cats, may be a discrete and easily applied morphometric tool to enhance detection of ductopenia in cats. However, application of this ratio required evaluation of ≥ 20 portal tracts with cross-sectioned portal elements to determine a mean BD:A value.

Long-term survival of dogs treated for gallbladder mucocele by cholecystectomy, medical management, or both.

BACKGROUND: Gallbladder mucoceles (GBM) typically are treated by cholecystectomy. Medical management rarely has been reported and medical and surgical management have not been compared. HYPOTHESIS/OBJECTIVES: To compare survival of dogs treated for GBM by medical management or cholecystectomy or both. ANIMALS: Eighty-nine client-owned dogs diagnosed with GBM that received cholecystectomy or medical treatment or both from 2011 to 2017. METHODS: Potential cases were identified by searching the medical records database. Data collected included signalment, clinicopathologic results, treatments, and ultrasonographic images and reports. Dogs were grouped according to the treatment received (medical management, surgical treatment, or both) that was chosen at the discretion of the attending veterinarian. Survival analysis was performed and prognostic variables identified and compared between treatment groups. RESULTS: Of dogs surviving at least 14 days after diagnosis, median survival times were 1802 (95% confidence interval [CI], 855-not reached) days, 1340 (95% CI, 444-1340) days, and 203 (95% CI, 18-525) days, for the surgical, medical, and medical then surgical treatment groups, respectively, and differed significantly (P < .0001). Gallbladder mucocele type (P = .05), serum alkaline phosphatase activity (P = .0001), and serum creatinine (P = .002) and phosphorus (P = .04) concentrations were associated with decreased survival across groups. Suspicion of biliary rupture on abdominal ultrasound (AUS) examination was correlated with increased survival in the surgical group (P = .02). CONCLUSIONS AND CLINICAL IMPORTANCE: Cholecystectomy for the treatment of GBM results in the best long-term survival in dogs surviving the immediate postoperative period (14 days) compared to medical management. Although medical management is associated with shorter survival compared to surgical treatment, it is a reasonable alternative when surgery cannot be pursued.

Histopathological distinction and evaluation of biliary and peribiliary cysts in pig liver.

The majority of hepatic cysts identified in animals are considered to derive from the intrahepatic bile ducts (biliary cysts). An alternative origin is the peribiliary glands located in the hilum of the liver and large portal tracts (peribiliary cysts). The distinction between biliary and peribiliary cysts, and whether these have different clinical significance, has rarely been considered previously. This study reports the pathological features of five cystic porcine livers. Four of these five livers had both biliary and peribiliary cysts and the fifth had only biliary cysts. Biliary cysts were not associated with distortion of adjacent hepatic parenchyma, whereas peribiliary cysts appeared to cause local compression and circulatory disturbance. It would therefore appear that peribiliary cysts have greater potential clinical significance than those of biliary origin.

Hepatobiliary diseases in buffalo (Bubalus bubalis): clinical, laboratory, and ultrasonographic findings.

This study describes ultrasonographic observations of five hepatobiliary diseases in buffalo (Bubalus bubalis). Fifty buffalo, including 20 clinically normal and 30 hepatobiliary diseased buffalo were enrolled in the study. Complete clinical, radiographic and ultrasonographic examinations and laboratory analyses were conducted. Focal parenchymal lesions including liver abscess (n = 12) and hepatic cyst (n = 6), diffuse parenchymal lesion (hepatobiliary cirrhosis, n = 5) and obstruction of hepatobiliary passages including cholestasis (n = 4), and hepatocholelithiasis (n = 3) were successfully imaged by ultrasonography. Hepatic abscess imaged as a hypoechoic to echogenic circumscribed mass of various diameters with a distinct echogenic capsule. Hepatic cyst imaged as a pear-shaped sac with a bright echogenic margin, anechoic content, and distal acoustic enhancement. In hepatobiliary fibrosis, the liver showed linear bands of increasing echogenicity with less distinct imaging of the portal vasculature. Cholestasis was imaged as dilatation of the gallbladder (GB) with wall thickening and homogeneous or heterogeneous contents. Hepatocholelithiasis imaged as an echoic structure within the hepatic parenchyma, or within and around the GB and bile duct, with more echogenicity of the hepatic parenchyma than normal. Ultrasonography can be an efficient rapid, noninvasive tool for screening of common hepatobiliary diseases in buffalo under field conditions.

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.

Retrospective analysis of canine gallbladder contents in biliary sludge and gallbladder mucoceles.

The pathophysiology of canine gallbladder diseases, including biliary sludge, gallbladder mucoceles and gallstones, is poorly understood. This study aimed to evaluate the component of gallbladder contents and bacterial infection of the gallbladder in order to elucidate the pathophysiology of biliary sludge and gallbladder mucoceles. A total of 43 samples of canine gallbladder contents (biliary sludge, 21 and gallbladder mucoceles, 22) were subjected to component analysis by infrared spectroscopy, and the resultant infrared spectra were compared with that of swine mucin. Of the 43 samples, 41 were also evaluated by aerobic and anaerobic bacterial culture. The contents of 20 (95.2%) biliary sludge and 22 (100%) gallbladder mucocele samples exhibited similar infrared spectra as swine mucin. Although biliary sludge and gallbladder mucocele contents exhibited similar infrared spectra, one sample of biliary sludge (4.8%) was determined to be composed of proteins. The rate of bacterial infection of the gallbladder was 10.0% for biliary sludge and 14.3% for gallbladder mucoceles. Almost all of the identified bacterial species were intestinal flora. These results indicate that the principal components of gallbladder contents in both gallbladder mucoceles and biliary sludge are mucins and that both pathophysiologies exhibit low rates of bacterial infection of the gallbladder. Therefore, it is possible that gallbladder mucoceles and biliary sludge have the same pathophysiology, and, rather than being independent diseases, they could possibly represent a continuous disease. Thus, biliary sludge could be considered as the stage preceding the appearance of gallbladder mucoceles.

Congenital dilatation of the large and segmental intrahepatic bile ducts (Caroli's disease) in two Golden retriever littermates.

Two, sibling, male Golden retriever puppies, 13 weeks of age, were presented with congenital biliary cysts of the liver involving both hepatic and segmental bile ducts, as well as bilateral polycystic kidney disease. Ultrasonography of the livers of both pups demonstrated segmental cystic lesions that were contiguous with the bile ducts. Histopathology revealed cystic ectatic bile duct hyperplasia and dysplasia with variable portal fibrosis in the liver, while in the kidneys there were radially arranged, cylindrically dilated cysts of the collecting ducts, which extended through the medulla and cortex. This pathology was compatible with that of congenital dilatation of the large and segmental bile ducts (Caroli's disease) described in humans, dogs and rats. In humans Caroli's disease has an autosomal recessive inheritance pattern, while in rats activation of the MEK5/ERK cascade initiates the biliary dysgenesis of Caroli's disease in this species. However, the exact mode of inheritance and pathogenesis of Caroli's disease in dogs is as yet unknown. Previous reports on congenital hepatic cystic diseases of the dog have described Caroli's disease like lesions in various breeds, but these are believed to be the 1st reported cases in the Golden retriever breed.

Arterial blood gas anomaly in canine hepatobiliary disease.

Arterial blood gas analysis is an important diagnostic and monitoring tool for respiratory abnormalities. In human medicine, lung complications often occur as a result of liver disease. Although pulmonary complications of liver disease have not been reported in dogs, we have frequently encountered hypoxemia in dogs with liver disorders, especially extrahepatic biliary obstruction. In addition, respiratory disorders account for 20% of perioperative fatalities in dogs. Therefore, in this study, we evaluated the respiratory status in dogs with hepatobiliary disease by arterial blood gas analysis. PaO2 and PaCO2 were measured. Alveolar-arterial oxygen difference (AaDO2), the indicator of gas exchange efficiency, was calculated. Compared to healthy dogs (control group), hepatobiliary disease dogs had significantly lower PaO2 and higher AaDO2. Hypoxemia (PaO2 of ≤80 mmHg) was observed in 28/71 dogs with hepatobiliary disease. AaDO2 was higher (≥30 mmHg) than the control group range (11.6 to 26.4 mmHg) in 32/71 hepatobiliary disease dogs. By classifying type of hepatobiliary disease, dogs with extrahepatic biliary obstruction and chronic hepatitis showed significantly lower PaO2 and higher AaDO2 than in a control group. Dogs with chronic hepatitis also had significantly lower PaCO2. The present study shows that dogs with hepatobiliary disease have respiratory abnormalities more than healthy dogs. Preanesthetic or routine arterial blood gas analysis is likely beneficial to detect the respiratory abnormalities in dogs with hepatobiliary disease, especially extrahepatic biliary obstruction and chronic hepatitis.

Use of Serum MicroRNAs as Biomarker for Hepatobiliary Diseases in Dogs.

BACKGROUND: Current biochemical indicators cannot discriminate between parenchymal, biliary, vascular, and neoplastic hepatobiliary diseases. MicroRNAs are promising new biomarkers for hepatobiliary disease in humans and dogs. OBJECTIVE: To measure serum concentrations of an established group of microRNAs in dogs and to investigate their concentrations in various types of hepatobiliary diseases. ANIMALS: Forty-six client-owned dogs with an established diagnosis of hepatobiliary disease and stored serum samples and eleven client-owned healthy control Labrador Retrievers. METHODS: Retrospective study. Medical records of dogs with parenchymal, biliary, vascular, or neoplastic hepatobiliary diseases and control dogs were reviewed. Concentrations of miR-21, miR-122, miR-126, miR-148a, miR-200c, and miR-222 were quantified in serum by real-time polymerase chain reaction. RESULTS: No different microRNA concentrations were found in the adenoma and congenital portosystemic shunt groups. In all other diseases, miR-122 concentrations were elevated with the highest concentration in the mucocele group (267-fold, CI: 40-1,768, P < .001). In dogs with biliary diseases, miR-21 and miR-222 were only increased in dogs with mucoceles (26-fold, CI: 5-141, P = .005 and 13-fold, CI: 2-70, P = .025, respectively). Uniquely increased microRNAs were found in the hepatocellular carcinoma group (miR-200c, 35-fold increase, CI: 3-382, P = .035) and the chronic hepatitis group (miR-126, 22-fold increase, CI: 5-91, P = .002). CONCLUSIONS AND CLINICAL IMPORTANCE: A microRNA panel consisting of miR-21, miR-122, miR-126, miR-200c, and miR-222 can distinguish between parenchymal, biliary, and neoplastic hepatobiliary diseases. Serum microRNA profiling is a promising new tool that might be a valuable addition to conventional diagnostics to help diagnose various hepatobiliary diseases in dogs.

Correlation between hepatobiliary scintigraphy and surgery or postmortem examination findings in dogs and cats with extrahepatic biliary obstruction, partial obstruction, or patency of the biliary system: 18 cases (1995-2004).

OBJECTIVE: To evaluate the usefulness of serum biochemical variables and scintigraphic study results for differentiating between dogs and cats with complete extrahepatic biliary obstruction (EHO) and those with partial EHO or patent bile ducts. STUDY DESIGN: Retrospective case series. ANIMALS: 17 dogs and 1 cat. PROCEDURE: Animals that underwent hepatobiliary scintigraphy and had either surgical or postmortem confirmation of the degree of bile duct patency were included. Scintigraphic images were evaluated and biliary tracts were classified as patent, partially obstructed but patent, or obstructed. Surgery or postmortem examination was considered the gold standard for diagnosis, and compared with those findings, sensitivity and specificity of scintigraphy were calculated. RESULTS: With absence of radioactivity in the intestinal tract as the diagnostic criterion for EHO, the sensitivity and specificity of scintigraphic diagnosis were both 83% when final images were acquired at 19 to 24 hours, compared with 100% and 33%, respectively, when 180 minutes was used as the cutoff time. Animals with partial biliary obstruction had less intestinal radioactivity that arrived later than that observed in animals with patent biliary tracts. CONCLUSIONS AND CLINICAL RELEVANCE: Animals in which intestinal radioactivity has not been observed after the standard 3 to 4 hours should undergo additional scintigraphic imaging. Findings in animals with partial biliary obstruction include delayed arrival of radioactivity and less radioactivity in the intestine. Distinguishing between complete and partial biliary tract obstruction is important because animals with partial obstruction may respond favorably to medical management and should not be given an erroneous diagnosis of complete obstruction.

Hepato-biliary coccidiosis in a dairy goat.

Hepato-biliary coccidiosis is reported in a diary goat that died of liver failure. Two types of lesions were seen in the liver. In the biliary type, coccidial oocysts, schizonts, gametes and gametocytes were seen in the epithelium of the bile duct, the wall of which was highly fibrosed. The hepatic type was in the form of granuloma, composed of oocysts and macrophages encapsulated in a fibrous capsule. Hepatic lymph nodes were diffusely scattered with oocysts and macrophages. Liver coccidiosis was found to be unresponsive to oral sulphamethazine treatment.

Identification of carbohydrates on Eimeria stiedai sporozoites and their role in the invasion of cultured cells in vitro.

The carbohydrates present on Eimeria stiedai sporozoites and their functional role in the process of invasion of host cells were examined. Lectin-binding sites on the surface of sporozoites were detected by means of peroxidase-conjugated lectins. Sporozoites showed specific binding with UEA-I and PNA lectins, which bind L-fucose and D-galactose, respectively. Exposure of sporozoites to 100 microg/ml UEA-I significantly reduced their ability to invade primary rabbit liver biliary epithelial cells, but similar treatment with PNA had no such effect. Pre-incubation of these cells in Dulbecco's minimum essential medium containing 10% fetal bovine serum and 1% L-fucose suppressed the invasion activity of the sporozoites, but pre-incubation of the sporozoites in the same medium without L-fucose had no effect on cell penetration. D-galactose added to the medium had no effect on the invasion activity of sporozoites. These results indicate that L-fucose residues on E. stiedai sporozoites and L-fucose-binding sites on host cells both are associated with the recognition and/or invasion process.

Mouse strain difference in bile duct lesions induced by swine serum injections.

The mouse strain difference in bile duct lesions was studied on male A/J, BALB/c, C57BL/6, C3H/He, DBA/2 and DDY mice 4 weeks old given intraperitoneal injections of swine serum (0.05 or 0.2 ml per mouse) twice a week for 4 weeks. The hepatic lesions were restricted to the portal tract. Biliary epithelial cells showed hypertrophy and hyperplasia, and eosinophilic and homogeneous or needle-shaped material appeared in the cytoplasm of such hypertrophied epithelial cells and in the ductular lumen. Around these damaged biliary epithelia, eosinophil leukocyte and plasma cell infiltration with proliferation of collagen fibres was commonly detected. These changes became more apparent with increasing size of bile duct. Such histopathological characteristics of hepatic lesions were essentially the same in all strains, but the severity showed a clear strain difference: the lesion was marked in the DDY, A/J and BALB/c strains, moderate in C3H/He and slight in C57BL/6 and DBA/2. A high production of anti-swine-serum antibodies associated with a marked increase in the number of mouse IgG-producing lymphocytes in the spleen was detected in the strains showing the marked hepatic lesions.

Cholelithiasis in four horses.

Four cases of cholelithiasis in horses were reviewed. Two horses were examined because of recurrent abdominal pain. Clinical laboratory data, results of physical examination, and history indicated biliary obstruction. In 1 case, B-mode ultrasonography aided in the diagnosis, which was confirmed at necropsy. In 2 horses, the biliary calculi were incidental necropsy findings.

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)

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)