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Objective: To report clinical signs, biological anomalies, treatment, and outcome in domestic ferrets with cholecystitis, describe the ultrasonographic features of cholecystitis, and compare the ultrasonographic appearance of the hepatobiliary system between diseased and healthy ferrets., Methods: 11 ferrets with confirmed cholecystitis and abdominal ultrasonography were retrospectively included. Ten healthy ferrets were prospectively recruited to undergo hepatobiliary abdominal ultrasonography. Comparisons of explanatory variables (group, age, body weight, and sex) were performed., Results: The most common clinical signs were nonspecific, and icterus was observed in 1/4 of diseased ferrets. Compared with healthy individuals, diseased ferrets showed a larger common bile duct (CBD; ≥ 2.8 mm), a thicker CBD wall (≥ 0.7 mm), a thicker gallbladder (GB) wall, more frequent echoic GB luminal content, visible intrahepatic bile ducts, and a greater GB volume. Bile culture was positive in 9/11 mostly for Escherichia coli (8/9). Bile cytology indicated septic purulent cholecystitis in 7/7 ferrets. Survival time after antibiotic treatment ranged from 6 to 104 weeks, with a median of 36 weeks., Conclusions: Ferrets with cholecystitis presented with nonspecific clinical signs and frequently showed hyperbilirubinemia. Ultrasonography findings such as enlarged CBD, thickened CBD wall, thicker GB wall, GB sludge, visible intrahepatic bile ducts, and enlarged GB may suggest cholecystitis. Escherichia coli was commonly isolated from bile. The medium-term mortality rate was high despite targeted antibiotherapy., Clinical Relevance: This is the first study describing the clinical signs, biological anomalies, ultrasonographic findings, and outcomes after treatment in a series of domestic ferrets with cholecystitis.

Background: Total serum bilirubin concentration (TBIL) can provide useful information on several pathophysiological conditions in cats. Nevertheless, whether the variable severity classification of hyperbilirubinemia can reliably indicate certain disease processes or predict a biliary obstruction (BO) has not been investigated., Hypothesis/objective: Determine if hyperbilirubinemia of variable severity can assist clinicians to identify BO, which often is considered a surgical emergency., Animals: Two-hundred sixteen client-owned cats., Methods: Data were retrospectively collected from all cats (January 2015-August 2022) with an increased TBIL (>0.58 mg/dL [>10 μmol/L]) presented to 3 referral centers in the United Kingdom (UK). Presenting clinical features and diagnostic outcomes were collected. The predictive ability of TBIL to indicate BO was evaluated by multivariable binary logistic regression modeling and receiver operating characteristic (ROC) curves., Results: Median TBIL was 1.73 mg/dL (range, 0.59-26.15; 29.5 μmol/L; range, 10.1-447.1) with severity classification of hyperbilirubinemia categorized as mild (>0.58-2.92 mg/dL; >10-50 μmol/L; 68.1%), moderate (>2.92-5.85 mg/dL; >50-100 μmol/L; 17.6%), severe (>5.85-11.70 mg/dL; >100-200 μmol/L; 9.7%) and very severe (>11.70 mg/dL; >200 μmol/L; 4.6%). Biliary obstruction was present in 17 (7.9%) cats, all of which received recommendation for emergency surgery. Median TBIL in cats with BO (9.69 mg/dL; 165.7 μmol/L) differed significantly from those without obstruction (1.51 mg/dL; 25.8 μmol/L; P < .01). The optimal TBIL cut-off to discriminate between cats with and without BO was ≥3.86 mg/dL (≥66 μmol/L) with a sensitivity of 94.1% and specificity of 82.4%. Using multivariable logistic regression, as age increased, the odds of BO increased significantly (odds ratio, 1.20; 95% confidence interval, 1.01-1.42; P = .04)., Conclusions and Clinical Importance: As part of a thorough clinical assessment, the severity classification of hyperbilirubinemia has the potential to predict the likelihood of a BO and to discriminate between cats that may or may not require surgery for BO at a suggested cut-off of ≥3.86 mg/dL (≥66 μmol/L). Alongside TBIL, age is also useful when assessing for the likelihood of BO in a cat presented with hyperbilirubinemia., (© 2024 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

A 6-year-old castrated male greyhound dog was referred for hemophagocytic histiocytic sarcoma (HHS) diagnosed following splenectomy. Severe thrombocytopenia, mild hypoalbuminemia, mild hypocholesterolemia, and mild hyperbilirubinemia were present. Abdominal ultrasound findings were concerning for hepatic metastasis. Doxorubicin and zoledronate combination therapy was initiated. The dog improved clinically and its thrombocytopenia, hypoalbuminemia, and hyperbilirubinemia resolved. The dog appeared well for 147 d before tumor progression was noted. The dog was treated with lomustine as a final measure, with no response. The dog survived for 6 mo with chemotherapy. To the authors' knowledge, this is the first report of clinical benefit of chemotherapy for HHS. Key clinical message: Doxorubicin should be considered for treating canine HHS since this variant of the disease is historically refractory to lomustine. Further research regarding efficacy of doxorubicin and zoledronate should be pursued., (Copyright and/or publishing rights held by the Canadian Veterinary Medical Association.)

Objective: The geographical distribution of feline cytauxzoonosis is expanding in the US. Clinical signs of feline cytauxzoonosis, including lethargy, anorexia, and icterus, are similar to hepatic lipidosis and cholangiohepatitis. Hematologic and serum biochemical abnormality patterns may assist practitioners in prioritizing feline cytauxzoonosis as a differential diagnosis over hepatic lipidosis and cholangiohepatitis., Sample: Hematology and serum biochemical profiles of cats with naturally acquired feline cytauxzoonosis, hepatic lipidosis, or cholangiohepatitis., Procedures: Retrospective search and analysis of the Kansas State Veterinary Diagnostic Laboratory or Kansas State University Veterinary Health Center records between January 2007 and June 2018 for cats with cytauxzoonosis, hepatic lipidosis, or cholangiohepatitis., Results: Patients with acute feline cytauxzoonosis presented with frequent nonregenerative anemia (20/28 [71%]), leukopenia (23/28 [82%]), thrombocytopenia (23/23 [100%]), hyperbilirubinemia (27/28 [97%]), hypoalbuminemia (26/28 [93%]), reduced (18/28 [64%]) or low normal (10/28 [36%]) serum ALP activity, and hyponatremia (23/28 [82%]). Reduced ALP activity was unique to cats with feline cytauxzoonosis relative to hepatic lipidosis and cholangiohepatitis. No correlation between the severity of anemia and the magnitude of hyperbilirubinemia was identified in feline cytauxzoonosis patients., Clinical Relevance: The combination of nonregenerative anemia, leukopenia, thrombocytopenia, hyperbilirubinemia, and reduced serum ALP activity in icteric cats may increase the clinical suspicion, but is not pathognomonic, for acute feline cytauxzoonosis. Hematologic and serum biochemical abnormalities of naturally acquired feline cytauxzoonosis are like those reported with feline bacterial sepsis. Blood smear evaluation for intraerythrocytic Cytauxzoon felis piroplasms, tissue aspirates for schizont-laden macrophages, and/or molecular testing are required to diagnose feline cytauxzoonosis.

Gallbladder mucocele (GBM) is a common extra-hepatic biliary syndrome in dogs with death rates ranging from 7 to 45%. Therefore, the aim of this study was to identify the association of survival with variables that could be utilized to improve clinical decisions. A total of 1194 dogs with a gross and histopathological diagnosis of GBM were included from 41 veterinary referral hospitals in this retrospective study. Dogs with GBM that demonstrated abnormal clinical signs had significantly greater odds of death than subclinical dogs in a univariable analysis (OR, 4.2; 95% CI, 2.14-8.23; P<0.001). The multivariable model indicated that categorical variables including owner recognition of jaundice (OR, 2.12; 95% CI, 1.19-3.77; P=0.011), concurrent hyperadrenocorticism (OR 1.94; 95% CI, 1.08-3.47; P=0.026), and Pomeranian breed (OR, 2.46; 95% CI 1.10-5.50; P=0.029) were associated with increased odds of death, and vomiting was associated with decreased odds of death (OR, 0.48; 95% CI, 0.30-0.72; P=0.001). Continuous variables in the multivariable model, total serum/plasma bilirubin concentration (OR, 1.03; 95% CI, 1.01-1.04; P<0.001) and age (OR, 1.17; 95% CI, 1.08-1.26; P<0.001), were associated with increased odds of death. The clinical utility of total serum/plasma bilirubin concentration as a biomarker to predict death was poor with a sensitivity of 0.61 (95% CI, 0.54-0.69) and a specificity of 0.63 (95% CI, 0.59-0.66). This study identified several prognostic variables in dogs with GBM including total serum/plasma bilirubin concentration, age, clinical signs, concurrent hyperadrenocorticism, and the Pomeranian breed. The presence of hypothyroidism or diabetes mellitus did not impact outcome in this study., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A 10-year-old spayed female Miniature Poodle was presented to the University of Georgia veterinary teaching hospital for evaluation of lethargy, vomiting and anorexia of 4 days' duration. Physical examination, history and a minimum database led to a diagnosis of immune-mediated hemolytic anemia accompanied by marked hyperbilirubinemia. Refractometric protein determination was within the reference interval, whereas the biuret method indicated hypoproteinemia. This discrepancy was attributed to interference of bilirubin and biliverdin with the spectrophotometric read-out of the biuret total protein assay. The albumin concentration, determined by bromcresol green, and refractometric total protein were less affected by this interference., (© 2014 American Society for Veterinary Clinical Pathology and European Society for Veterinary Clinical Pathology.)

Objective: To determine whether high serum bilirubin concentrations interfere with the measurement of serum total protein concentration by refractometry and to assess potential biases among refractometer measurements., Design: Evaluation study., Sample: Sera from 2 healthy Greyhounds., Procedures: Bilirubin was dissolved in 0.1M NaOH, and the resulting solution was mixed with sera from 2 dogs from which food had been withheld to achieve various bilirubin concentrations up to 40 mg/dL. Refractometric total protein concentrations were estimated with 3 clinical refractometers. A biochemical analyzer was used to measure biuret assay-based total protein and bilirubin concentrations with spectrophotometric assays., Results: No interference with refractometric measurement of total protein concentrations was detected with bilirubin concentrations up to 41.5 mg/dL. Biases in refractometric total protein concentrations were detected and were related to the conversion of refractive index values to total protein concentrations., Conclusions and Clinical Relevance: Hyperbilirubinemia did not interfere with the refractometric estimation of serum total protein concentration. The agreement among total protein concentrations estimated by 3 refractometers was dependent on the method of conversion of refractive index to total protein concentration and was independent of hyperbilirubinemia.

A severe increase in total bilirubin coincided with a decline in neurologic status to comatose in a 9 yr old spayed female mixed-breed dog being treated for immune-mediated hemolytic anemia. MRI of the brain was performed to investigate potential causes for the neurologic signs. MRI revealed bilaterally symmetrical hyperintensities within the caudate nuclei, globus pallidus, thalamus, deep cerebellar nuclei, and cortical gray matter on T2-weighted and fluid-attenuated inversion recovery (FLAIR) sequences, which coincided with areas of bilirubin deposition and neuronal necrosis (kernicterus) identified on necropsy examination. This is the second case report of an adult dog exhibiting kernicterus, and the first report to document MRI findings associated with that condition. Kernicterus is an uncommonly reported complication of hyperbilirubinemia in dogs, but is potentially underreported due to difficulties in recognizing subtle lesions and distinguishing kernicterus from other potential causes of neurologic abnormalities with readily available antemortem tests. MRI may be helpful in supporting the diagnosis of kernicterus.

The objective of this study was to evaluate three commercially-available human assays for the determination of adiponectin, ghrelin and insulin-like growth factor 1 (IGF-1) concentrations in feline serum samples. Intra- and interassay coefficients of variation were lower than 20%, 15% and 6% for adiponectin, ghrelin and IGF-1 assays, respectively. Dilutions of feline serum pools resulted in linear regression equations in all kits. Mean recovery of adiponectin, ghrelin and IGF-1 assays were 107%, 102% and 105%, respectively. Significant differences were detected in adiponectin and ghrelin concentrations between lean and obese cats (P <0.05 in both cases), but there was no difference in IGF-1 concentrations (P = 0.12).

A 2-year-old female neutered Somali cat was presented with vomiting and acute onset jaundice 1 year after diagnosis of pyruvate kinase (PK) deficiency. Diagnostic investigations revealed a moderate regenerative haemolytic anaemia, severe hyperbilirubinaemia and elevated liver enzymes. Ultrasonography revealed marked distension of the gall bladder and common bile duct (CBD), consistent with extrahepatic biliary obstruction (EHBO). At cholecystotomy, the gall bladder contained purulent material, and two obstructive choleliths were removed from the CBD by choledochotomy. The cat recovered from surgery uneventfully, and serum liver enzymes and bilirubin normalised within 10 days. Postoperative treatment consisted of cephalexin, metronidazole and ursodeoxycholic acid (UDCA). Bacterial culture of the gall bladder contents yielded a pure growth of an Actinomyces species. Cholelith analysis revealed that they consisted of 100% bilirubin. Antibiotic treatment was stopped 4 weeks after surgery but UDCA was continued indefinitely. The cat remains clinically well with no recurrence of cholelithiasis 20 months after initial presentation. This is the first report of successful treatment and long-term follow-up of a cat with EHBO due to bilirubin cholelithiasis in association with PK deficiency-induced chronic haemolysis.

C-reactive protein (CRP) and haptoglobin (Hp) are well-known acute phase proteins in the dog. Currently, a commercial ELISA and a colorimetric assay are the methods of choice for measuring CRP and Hp, respectively; however, these assays showed interference when using haemolysed, lipaemic or hyperbilirubinaemic samples. Recently, time-resolved immunofluorometric assays (TR-IFMAs) have been developed for measuring canine CRP and Hp. The aim of the present study was to evaluate the effect of increasing concentrations of haemoglobin, lipids and bilirubin in CRP and Hp serum measurements using these new fluoroimmunoassays. Haemolysis was produced by freezing blood cells at -20 degrees C. The haemolysate was added to pooled sera at final concentrations of 0, 2.5, 5, 10, 20 and 40 g/L. A commercial emulsion of triglycerides was added to homologous pooled sera at 0, 0.35, 0.7, 1.4, 2.8, 5.6 and 11.2 mmol/L. Bilirubin, initially dissolved in dimethyl sulphoxide, was added to pooled sera at 0, 64.2, 128.4, 256.8, 513.7 and 1027.4 micromol/L. Addition of fresh haemolysate, triglycerides or bilirubin to serum samples did not affect either CRP or Hp concentrations (P > or = 0.18), so the TR-IFMAs could be an alternative to the traditional tests for measuring canine CRP and Hp in those laboratories where immunofluorometric assays are available.

Objective: To determine physical examination findings, clinicopathologic changes, and prognosis in dogs with zinc toxicosis., Design: Retrospective case series., Animals: 19 dogs with zinc toxicosis., Procedures: Medical records from 1991 through 2003 were searched for animals with a diagnosis of zinc toxicosis. Information concerning signalment, body weight, historical findings, initial owner complaints, physical examination findings, clinicopathologic findings, blood zinc concentrations, source of zinc, treatments given, duration of hospital stay, and outcome was collected., Results: Records of 19 dogs with zinc toxicosis were reviewed. The most common historical findings were vomiting (n = 14) and pigmenturia (12). The most common clinicopathologic findings were anemia (n = 19) and hyperbilirubinemia (12). Median age was 1.3 years, and median weight was 5.6 kg (12.3 lb). The prognosis was favorable, with 17 dogs surviving after a median hospital stay of 2 days., Conclusions and Clinical Relevance: Hemolytic anemia as a result of zinc toxicosis appeared to affect young small-breed dogs more frequently than older large-breed dogs. The prognosis with treatment is good, and most affected dogs had a short hospital stay.

Objective: To identify factors associated with outcome in cats with extrahepatic biliary tract obstruction (EHBTO) that undergo biliary diversion surgery., Design: Retrospective case series., Animals: 22 cats., Procedures: Medical records of cats with surgically confirmed EHBTO that underwent cholecystoenterostomy were reviewed., Results: Clinical signs and physical examination findings included vomiting, anorexia, icterus, lethargy, weakness, and weight loss. Common clinicopathologic abnormalities included high serum hepatic enzyme activities and serum bilirubin concentration. Abdominal ultrasonography was performed in 21 cats, and all 21 had findings consistent with EHBTO. Eleven of 15 cats in which blood pressure was monitored had intraoperative hypotension. Eighteen cats had anemia following surgery, and 14 cats had persistent hypotension. Extrahepatic biliary tract obstruction was a result of neoplasia in 9 cats and chronic inflammatory disease in 13. Fourteen cats survived long enough to be discharged from the hospital, but only 6 survived > 6 months after surgery, all of which had chronic inflammatory disease. Median survival time for cats with neoplasia (14 days) was significantly shorter than that for cats with inflammatory disease (255 days). No other variable was associated with outcome., Conclusions and Clinical Relevance: Results suggest that cats with EHBTO secondary to neoplasia have a poorer prognosis than cats with EHBTO secondary to chronic inflammatory disease. However, the overall prognosis for cats with EHBTO undergoing cholecystoenterostomy must be considered guarded to poor, and the incidence of perioperative complications is high.

Previously, we have demonstrated that hepatic venous injection of pcDNA3hUGT1A1 expressing human bilirubin glucuronosyl transferase 1A1 (hUGT1A1) under the control of the cytomegalovirus promoter results in excretion of bilirubin glucuronides in bile and significant decrease in serum bilirubin for at least 2 weeks in the Gunn rat, an animal model of Crigler-Najjar syndrome type I. In this study we compared repeat delivery of pcDNA3hUGT1A1 with single injection of pBShUGT1A1 expressing hUGT1A1 under liver-specific regulatory control, for treatment of hyperbilirubinemia in the Gunn rat. Although repeat injections of pcDNA3hUGT1A1 consistently reduced serum bilirubin levels, the effect did not exceed 2 weeks; hUGT1A1 was detectable in livers only for 2 weeks, despite the presence of vector and transcript for at least 1 month. In contrast, injection of pBShUGT1A1 resulted in persistence of vector, transcript, and recombinant protein and sustained correction of hyperbilirubinemia for at least 8 months; furthermore, renal tubular damage, the principal manifestation of chronic bilirubin toxicity in the Gunn rat, was prevented. Sera from animals treated with pBShUGT1A1 consistently contained anti-hUGT1A1 antibodies, but a significant increase in the number of hepatic CD4(+) and CD8(+) cells was seen only in the pcDNA3hUGT1A1 group; thus liver-specific expression of hUGT1A1 may attenuate immune response. Our results provide further evidence of the feasibility of long-term correction of hepatic enzyme deficiencies with plasmid vectors optimized for expression in the liver.

The objective of the present study was to determine the effects that hemolysis, lipemia, bilirubinemia, and anticoagulants might have on the most commonly used assays for C-reactive protein and serum amyloid A, and determination of ceruloplasmin values in dogs. Solutions of hemoglobin, lipid, and bilirubin were added to serum aliquots. Additionally, serum and plasma samples with different anticoagulants (heparin, EDTA, and citrate) were obtained from healthy dogs. Hemolysis, lipemia, and hyperbilirubinemia interfered significantly with the C-reactive protein and ceruloplasmin results, but not with those for the serum amyloid A assay. The use of anticoagulants produced significant changes in the results for the assays tested. However, the magnitude of the differences caused by the interfering substances does not appear to have an important impact on the clinical interpretation of the tests.

Validation for canine serum of 2 commercially available time-resolved fluoroimmunoassays (TR-FIAs) designed for analysis of cortisol and free thyroxine (fT4) in human serum was carried out. Included was the study of interference by hemolysis, lipemia, and bilirubinemia. With the dissociation enhancement lanthanide fluoroimmunoassay kits, the intra-assay coefficient of variation (CV) ranged from 6.4% to 8.7% for cortisol and from 5.3% to 9.8% for fT4; the interassay CVs ranged from 5.8% to 10.8% and from 3.9% to 14.1%, respectively. Accuracy was evaluated by comparing cortisol and fT4 results obtained with TR-FIA and those obtained with a validated enzyme-linked immunosorbent assay (ELISA) and an equilibrium dialysis (ED) assay, respectively. The regression equations obtained were y = 0.57x + 1.18 (r2 = 0.90) for cortisol and y = 0.87x + 0.82 (r2 = 0.93) for fT4. The limits of detection for cortisol and fT4 were 4.84 nmol/L and 2.68 pmol/L, respectively. The results of adrenocorticotropin-stimulation and dexamethasone-suppression tests were similar to those published previously; likewise, serial dilution of a canine serum sample with a high cortisol content demonstrated that the TR-FIA was immunologically specific. Serial dilution of a serum sample with a high fT4 concentration showed a methodologic bias, a dependence on serum binding capacity, which indicates that the results obtained with this method should be interpreted with caution. Finally, hemolysis and lipemia significantly interfered with cortisol and fT4 measurements, whereas bilirubinemia did not affect the results.

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.

The influence of various pathological conditions on fructosamine levels in normoglycaemic dogs and cats was investigated. The most frequent and most pronounced deviations were found in animals with hypoproteinaemia, in which fructosamine was significantly lower than in the controls. In 66 per cent of the dogs and 67 per cent of the cats with hypoproteinaemia the levels were below the reference range. In the dogs the concentration of fructosamine was correlated with the level of albumin, but in the cats it was correlated with the level of total protein. Dogs with hyperlipidaemia and azotaemia also had significantly lower levels of fructosamine; 38 per cent of those with hyperlipidaemia and 47 per cent of those with azotaemia had fructosamine levels outside the reference range. No significant changes in fructosamine were detected in dogs or cats with hyperproteinaemia or hyperbilirubinaemia, or in cats with hyperlipidaemia or azotaemia.

Objective: To identify risk factors for enterolithiasis in horses., Design: Matched case-control study., Animals: 26 horses with enteroliths, 104 horses with other causes of colic that underwent surgery (52 horses, surgical control group) or were treated medically (52 horses, nonsurgical control group)., Procedure: Medical records were reviewed for horses with enteroliths and control horses. Information collected included signalment, anamnesis, and findings on physical examination and clinicopathologic testing at admission. Horses with enteroliths and control horses were compared by means of conditional logistic regression to identify factors associated with enterolithiasis., Results: Horses that were fed alfalfa hay, spent < or = 50% of time outdoors, or were Arabian or miniature breeds had an increased risk of developing enteroliths. Horses with enteroliths were more likely to have been hyperbilirubinemic and to have had clinical signs > 12 hours prior to admission., Conclusions and Clinical Relevance: Breed and diet appear to influence the risk of enterolithiasis; other management factors also may influence development of enteroliths. Duration of clinical signs may be longer and signs may be less severe among horses with enteroliths, compared with horses with other causes of colic.

Interferences caused by haemolysis, lipaemia and bilirubinaemia on prothrombin time (PT), activated partial thromboplastin time (APTT) and thrombin time (TT in normal canine plasma samples were studied using commercially available reagents and a steel ball coagulometer. Haemolysis significantly interfered with APTT (P = 0.0076) and TT (P = 0.0292). Regression analysis showed that TT was significantly shortened as haemoglobin concentrations increased. Lipaemia increased as demonstrated by regression analysis. Bilirubin significantly interfered with PT (P=0.0003) and APTT (P=0.002). Although statistically significant, none of the differences found were of clinical relevance.

The possible interference of haemolysis, lipaemia and bilirubinaemia on commercially available enzyme-linked immunosorbent assays (test kits Enzymun-Test; Boehringer Mannheim) for cortisol and free thyroxine (FT4) in canine plasma samples was studied. Serum samples from 20 clinically normal dogs were enriched in vitro with different amounts of fresh haemolysate, lipid and bilirubin and compared with the original sera. The tests were used in connection with the analyser system Enzymum-Test (Boehringer Mannheim) System ES300. Haemolysis significantly (P = 0.039) interfered with the accuracy of FT4 determination independent of haemoglobin concentrations. Thus, haemolysis should be avoided in FT4 testing by competitive enzyme immunoassay. Lipaemia significantly interfered (P = 0.0015) with cortisol determination but not with FT4 determination (P = 0.41). Regression analysis showed that FT4 concentration significantly increased as triglyceride levels increased, especially at concentrations greater than 125 mg dL-1. The positive bias observed was of no diagnostic importance for cortisol results and the increase of FT4 levels could be precisely predicted by linear regression analysis. The addition of bilirubin significantly (P = 0) interfered with cortisol testing but, as with lipaemia, the magnitude of the differences were of no clinical significance.

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a well-characterized X-linked inherited disorder in humans but has not been reported in horses. We describe a persistent hemolytic anemia and hyperbilirubinemia due to a severe G6PD deficiency in an American Saddlebred colt. Other abnormalities in the colt's erythrocytes as compared with those of healthy horses (n = 22-35) included increased activities of hexokinase and pyruvate kinase, decreased concentrations of reduced glutathione and reduced nicotinamide adenine dinucleotide phosphate (NADP), and increased concentration of oxidized NADP. Morphologic abnormalities included eccentrocytosis, pyknocytosis, anisocytosis, macrocytosis, and increased number of Howell-Jolly bodies. Scanning and transmission electron microscopic examinations revealed that eccentrocytes had contracted to spherical regions and thin collapsed regions. Eccentrocytes were more electron dense than were normal erythrocytes when examined by transmission electron microscopy. When exposed to acetylphenylhydrazine, erythrocytes from the G6PD-deficient colt produced more and smaller Heinz bodies than did erythrocytes from normal horses. Abnormalities in the colt's dam included presence of eccentrocytes and pyknocytes; her average erythrocyte G6PD activity was slightly below the range of reference values.

On routine blood screens, persistent conjugated hyperbilirubinemia was discovered in two groups of closely related adult female golden lion tamarins (Leontopithecus rosalia rosalia, n = 8). Bromosulfophthalein (BSP) retention tests were performed on four hyperbilirubinemic and three control tamarins. BSP excretion was delayed in hyperbilirubinemic tamarins as compared with controls. Grossly, liver of affected tamarins was dark brown to black, with a prominent reticulated pattern. Histologic examination revealed abundant intrahepatic pigment, primarily in a centrilobular and midzonal distribution. Most of the pigment did not react with Perls' Prussian blue method for iron, Hall's method for bilirubin, or the Armed Forces Institute of Pathology acid-fast method for lipofuscin but was positive with Fontana and lipofuscin-ferric ferricyanide reduction techniques. Liver from control golden lion tamarins had intrahepatocellular Perls' iron-positive pigment diffusely throughout the lobule with a small amount of Fontana method-positive pigment. Ultrastructurally, hepatocytes from a hyperbilirubinemic tamarin contained pleomorphic electron-dense structures within lysosomes. Transport studies demonstrated secretion of fluorescein isothiocyanate-labeled glycocholic acid, a fluorescent bile acid analog, into bile canaliculi and no secretion of carboxydichlorofluorescein diacetate, a non-bile acid organic anion, by liver from a hyperbilirubinemic tamarin. In contrast, control liver secreted carboxydichlorofluorescein diacetate readily into bile canaliculi. The clinicopathologic presentation of this syndrome in golden lion tamarins is similar to that described for Dubin-Johnson syndrome of human beings.

Persistent hyperbilirubinemia and icterus are described in a healthy 4-year-old Thoroughbred horse. Hyperbilirubinemia was not related to food intake and was not associated with evidence of increased hemolysis or with acquired hepatic disease. The hyperbilirubinemia was thought to be a result of inappropriate conjugation of bilirubin rather than any abnormality in bilirubin uptake or excretion. The bilirubinemia in this horse appears most similar to a human syndrome, caused by a familial deficiency of bilirubin-uridine diphosphate glucuronyl transferase.

Median corpuscular fragility of erythrocytes does not differ significantly between fed and fasted Bolivian and Brazilian squirrel monkeys and are similar to values reported in humans and rhesus monkeys. This report further confirms that the fasting hyperbilirubinemia present only in Bolivian squirrel monkeys with a Gilbert-like syndrome is not due to an increased fragility of erythrocytes and should be classified as a nonhemolytic hyperbilirubinemia.

Alterations in serum lipid and lipoprotein concentrations in ponies with experimentally induced liver disease were investigated. Hepatocellular damage was induced, using a nonlethal dose of carbon tetrachloride. In a separate group of ponies, obstructive jaundice was induced by surgical ligation of the common bile duct. Over a 6-day period, blood samples were obtained from ponies after treatment with carbon tetrachloride and for 12 days in ponies subjected to surgery. Serum cholesterol and triglyceride concentrations were unaffected in both groups of ponies, except for significantly (P less than 0.01) high triglyceride concentration in ponies of the ligated group during the second postsurgical week. This increase was most likely attributable to anorexia observed during that period. Hyperbilirubinemia was observed early in ponies of the ligated group; most of the bilirubin was of the conjugated type. Using electrophoretic and ultracentrifugal methods, serum lipoprotein alterations were detected only in ponies of the ligated group. Increases of very low-density and low-density lipoprotein cholesterol concentrations and decrease in high-density lipoprotein cholesterol concentration were found. Although no changes were seen in total serum cholesterol concentration, a redistribution of lipoprotein cholesterol was observed in ponies of the ligated group. Similar alterations in lipoprotein distribution have been found in dogs, rats, and human beings with obstructive jaundice and cholestasis. The association between serum lecithin:cholesterol acyl transferase activities and these lipoprotein alterations remains to be elucidated.

Pulmonary carbon monoxide (CO) excretion rates (VeCO) were 50% greater, on average, in Bolivian squirrel monkeys (BoSMs) which exhibit a unique fasting hyperbilirubinemia (FH), than in fasted control Brazilian squirrel monkeys (BrSMs). Since the catabolism of heme produces equimolar amounts of CO and bilirubin, the increased VeCOs are consistent with concurrent increases in endogenous bilirubin production rates. Tin-protoporphyrin, a competitive inhibitor of heme oxygenase, significantly decreased both the VeCO and serum bilirubin level in fasted BoSMs. Overproduction of bilirubin may be responsible in part for the marked FH in BoSMs.

The paper describes a case of jaundice in a three-year-old bassett hound. The illness was accompanied by hyperbilirubinaemia and raised serum levels of alkaline phosphatase and glutamic pyruvic transaminase, indicating the presence of both biliary obstruction and hepatocellular damage. Examination of liver biopsies on two occasions showed intrahepatic cholestasis and mild inflammatory change. The dog was treated with corticosteroid. The jaundice regressed after three months, hepatic functions returned to normal and the dog recovered. The cause of the jaundice was not determined.

Hyperbilirubinemia was present in 387 out of 1279 sick cattle admitted to the clinic of the Ontario Veterinary College. One hundred and ninety five of these had a total serum bilirubin of 17 mumol/L or greater. Clinical records, laboratory data and when available, pathology reports from these 195 animals were examined in an attempt to explain the reason for the high bilirubin levels. The hyperbilirubinemia in 187 of these was mainly due to an increase in unconjugated bilirubin. Jaundice, liver disease or anemia was not a feature and alkaline phosphatase was not elevated. The 195 animals with hyperbilirubinemia suffered from a variety of diseases that seemingly were unrelated to the increased bilirubin. The most frequently described signs were anorexia and rumen stasis. Liver disease was diagnosed in eight animals and in these clinical jaundice, and increased conjugated bilirubin and alkaline phosphatase was a feature. It was concluded that hyperbilirubinemia occurred in many diseases of cattle and in most instances was related to a failure of the liver to remove unconjugated bilirubin from the serum rather than to a failure of the liver to excrete conjugated bilirubin.

Serum biochemical analyses were done on F344 rats in the early and late stages of mononuclear cell leukemia. There were marked increases in serum bilirubin, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase and alkaline phosphatase. Increases in these parameters generally were more severe in the late stages of leukemia. Both direct and indirect-reacting bilirubin were increased with the unconjugated form predominating early and the conjugated form predominating late in the course of the disease. Lactate dehydrogenase isoenzyme determination correlated with histological examination indicated that liver damage was responsible for the observed changes. Urinalysis revealed marked hemoglobinuria, bilirubinuria and increased urine urobilinogen. Serum protein electrophoresis revealed marked reductions in the alpha globulin fractions.

The kinetics of unconjugated 3H-bilirubin are described in 25 healthy dogs and 35 dogs with spontaneous hepatobiliary or haemolytic disease, using a two-compartment model. The bilirubin production rates from erythrocyte degradation (PE), ineffective erythropoiesis (PI) and catabolism of hepatic haemoproteins (PL), were derived from the incorporation of 14C-glycine into haemoglobin and stercobilin. These combined measurements permitted an integral survey of bilirubin metabolism in health and disease. The concentration of unconjugated bilirubin in plasma and its fraction of total bilirubin levels were similar in hepatic and haemolytic disorders. This was explained by the highly increased bilirubin production rates in both types of disease. In addition, the hepatic bilirubin clearance was severely impaired in fulminant hepatitis and in cirrhosis, and moderately decreased in the other hepatobiliary diseases and in primary haemolysis. The erythrocyte lifespan was reduced in all animals but one. In addition to haemolysis, the contribution of PI and PL was variable, and in two dogs PL was the principle source of highly increased bilirubin production rates. These data indicate that the concentration of unconjugated bilirubin in plasma or its fraction of total pigments is unreliable in the discrimination of canine hepatobiliary disease from haemolytic disorders.

In dogs, the differentiation between haemolytic and cholestatic hepatobiliary diseases cannot be achieved by measuring of the unconjugated:conjugated bilirubin ratio, which is in contrast with generally held clinical concepts. The overlap of the bilirubin ratios between the two groups of icterus-generating diseases might in part be explained by deconjugation of conjugated bilirubin. Enzymatic cleavage by hepatic beta-glucuronidase might result in higher unconjugated bilirubin (UCB) fractions in cholestatic disease. The influence of deconjugation of bilirubins by beta-glucuronidase was investigated in 25 healthy dogs and 35 dogs with spontaneous hyperbilirubinemia due to either hepatobiliary or haemolytic disease. UCB and its mono- and diconjugates were measured by alkaline methanolysis and HPLC in plasma and liver tissue. The activity of beta-glucuronidase was also measured in both liver and plasma. In addition, semiquantitative histochemical quantitation of bilirubins in liver tissue was performed. The concentration and the fraction of UCB in plasma of dogs with hepatobiliary disease were not significantly different from those of dogs with autoimmune haemolytic anaemia. There was a correlation between the fraction of UCB in liver and plasma of jaundiced dogs (r = 0.42, P less than 0.01) and between the histochemically estimated and the biochemically measured total bilirubin concentration in liver tissue. There was no correlation between the beta-glucuronidase activity and either unconjugated or monoconjugated bilirubin in plasma or liver of diseased animals. The fraction and the concentration of UCB in the liver of dogs with hepatic and with haemolytic disease were identical. It is concluded that beta-glucuronidase activity is not the significant factor in explaining the similar levels and fractions of UCB in dogs with hyperbilirubinemia due to either hepatobiliary or haemolytic disease.

The use of animal models in the experimental production of liver diseases similar to those of man is still in its infancy. There is a need to discover new models more closely related to counterpart syndromes in man in the fields of hepatorenal syndrome, neonatal jaundice, Wilson's disease, cholelithiasis, viral hepatitis, biliary atresia, and cirrhosis, to mention only a few. With the continued indiscriminate inbreeding of companion animals as well as the planned inbreeding of laboratory animals, there is little doubt that many more will soon be available. The current availability of mutant rats and sheep with bilirubin transport defects has allowed for a better understanding of how organic anions are transported by the liver. Many other currently available experimental animal models herein briefly reviewed have been only superficially studied. It is the intent of this chapter to provide for post-doctoral students an appreciation for the many animal model systems available for experimental hepatic research.

The substantia nigra of various aged hyperbilirubinemic (Gunn) rats was studied by means of electron microscopy. The cytological features observed in the neuronal somata were the presence of (1) complex membranous bodies (CMBs), (2) dilated cisternae of granular endoplasmic reticulum, (3) single membrane bound vacuoles and (4) enlarged mitochondria. Nearly every neuronal soma studied in two week old Gunn rats contained CMBs, which consisted of several layers of membrane that usually, but not always surrounded small islands of cytoplasm. On occasion CMBs were seen to be directly connected with granular endoplasmic reticulum and, in a few instances, they were located within a cistern of endoplasmic reticulum. There were significantly fewer CMBs in the neuronal somata of adult Gunn rats. They were located peripherally in the somata or in the proximal portions of dendrites. Furthermore, in these animals the cytoplasm appeared normal and did not exhibit the features commonly seen in younger animals. Only a few hyperchromatic neurons were observed and no pronounced gliosis was evident. Therefore it is assumed that the majority of substantia nigra neurons recovered from the toxic effect of bilirubin or that the concentration of bilirubin deposited in the substantia nigra is not sufficient to be lethal. The hypothesis that is considered is that CMBs represent autophagic activity which results from exposure of neurons to bilirubin. The adjacent neurites and glia did not demonstrate the cytoplasmic changes that were characteristic of the neuronal somata.

The effects of several treatments and their routes of administration on the reduction of hyperbilirubinemia in 9 pony mares after a 3-day fast were studied. Treatments were as follows: glucose given at doses of 1.2, 2.4, and 3.7 mg/min/kg of body weight; refeeding the base-line diet; feeding straw; and IV administration of taurocholic acid at a dosage of 0.07 mumol/min/kg. The 3 glucose dosages were each given by 3 different routes: IV, intraduodenal, and intragastric. The smallest dosage of glucose given by IV route reduced the plasma bilirubin concentration only 7%, even though other measured values associated with fasting returned toward their base line; increased free fatty acid concentration was reduced by 50%; plasma insulin increased above base-line values. Except for the smallest glucose dose given by IV route, the effects of the routes of administration (IV less than intraduodenal less than intragastric) and of the doses of glucose were not significantly different. Taurocholic acid (given IV) was ineffective in reducing the plasma fasting bilirubin concentration. Refeeding the base-line diet reduced the hyperbilirubinemia by 66% in 12 hours, which was a significantly greater reduction than the effect of all other treatments except the largest dose of glucose given by intragastric route. Feeding straw was less effective than refeeding, causing only about a 30% reduction.

Blood coagulation values for normal sheep and lambs, using commercially available reagents for human coagulation, are reported. Of the domestic animal species for which coagulation values have been reported, the sheep most closely resembles those of humans. Factor VII deficiency has been found in some patients with Dubin Johnson syndrome. Sheep with the same defect were found to have no coagulation abnormality.