Chronic hepatitis (CH) is a common diagnosis in

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1 J Vet Intern Med 2007;21:33 39 Chronic Hepatitis in Labrador Retrievers: Clinical Presentation and Prognostic Factors Julia L. Shih, John H. Keating, Lisa M. Freeman, and Cynthia R.L. Webster Background: An increased incidence of chronic hepatitis has been reported in Labrador Retrievers. Hypothesis: A breed associated hepatopathy occurs in Labrador Retrievers. Animals: Twenty-four client-owned Labrador Retrievers. Methods: Medical records of dogs with histopathologic confirmation of chronic hepatitis were retrospectively reviewed. A clinical score based on clinical signs and the results of biochemical tests was generated for each dog. Hepatic biopsy specimens were scored for disease activity, fibrosis, and copper accumulation. Results: The median age was 9.3 years (range, years). Clinical signs included inappetence, vomiting, lethargy, and weight loss. All dogs had increases in serum activity of one or more hepatobiliary enzyme. Hyperbilirubinemia and hypoalbuminemia were present in 45% and 21% of dogs, respectively. The median clinical score was 2.9, with a range of 0 8. The median histopathology activity and the fibrosis scores were 3.5 (range, 1 6) and 3.0 (range, 0 4), respectively. Rhodaninepositive copper staining was present in 15 of 17 biopsy specimens, with a median score of 2.0 (range, 0 3). Median survival was 374 days (range, days). A prolonged prothrombin time (P 5.013) and thrombocytopenia (P 5.041) were associated with survival,2 months. The presence of anorexia (P 5.049), hypoglobulinemia (P 5.045), or prolonged partial thromboplastin time (P 5.033) were associated with shorter overall survival times. The clinical score correlated with survival time (P 5.030) and histopathologic staging (P 5.049). Conclusions and Clinical Importance: A progressive hepatopathy in Labrador Retrievers in this study was marked by chronic inflammation, fibrosis, and copper accumulation. A clinical scoring system that correlates with survival time may be useful as a noninvasive method to predict prognosis. Key words: Copper-associated hepatitis; Hepatitis; Increased serum liver enzymes; Liver disease. Chronic hepatitis (CH) is a common diagnosis in dogs; however, unlike its counterpart in humans, the etiology is poorly understood. In veterinary medicine, several breed associated hepatopathies have been reported. 1 6,a In Bedlington Terriers, West Highland White Terriers, Dalmatians, and Skye Terriers, these hepatopathies have been linked to inborn errors of copper metabolism. 2 6 In the Doberman Pinscher, both imbalances in copper metabolism and immunologic dysfunction have been tentatively linked to the etiology. 7 9 The cause of a Cocker Spaniel hepatopathy is unknown although some evidence exists to link it to an a-1 antitrypsin deficiency. 10 In people, CH is associated with viral disease (hepatitis B and C virus), autoimmune disease, inborn errors of metabolism (tyrosinemia, hematochromatosis, a-antitrypsin deficiency, Wilson s disease), alcohol ingestion, and insulin resistance/metabolic syndrome (nonalcoholic steatohepatitis). 11 An increased incidence of CH has been reported in Labrador Retrievers, although the clinical presentation of this disease and its outcome have not been reported. 12 Therefore, the purpose of this current retrospective study was 3-fold. First was to determine if an increased incidence of CH occurred in Labrador Retrievers being From the Department of Clinical Sciences (Shih, Freeman, Webster), Department of Biomedical Sciences (Keating), Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA. Presented as an abstract to the 2006 ACVIM Forum. Reprint requests: Cynthia RL Webster, DVM, 200 Westboro Rd, N Grafton, MA 01356; cynthia.leveille-webster@tufts.edu. Submitted March 20, 2006; Revised June 23, 2006; August 18, 2006; Accepted August 31, Copyright E 2007 by the American College of Veterinary Internal Medicine /07/ /$3.00/0 treated at our hospital and to describe the history, clinical signs, clinicopathologic abnormalities, diagnostic imaging findings, and outcome in dogs with this histopathologic diagnosis. Second was to assess the role of potential factors, including copper accumulation, in the etiology. Third was to define prognostic factors and to establish a clinical scoring system that can be used to follow the progression of CH in these dogs. Material and Methods The histopathology records at the Foster Hospital for Small Animals at Tufts Cummings School of Veterinary Medicine were reviewed for Labrador Retrievers with a biopsy-proven diagnosis of CH from 2000 to Requisite hepatic histologic characteristics for a diagnosis of CH as defined by the World Small Animal Veterinary Group were the presence of chronic inflammatory infiltrates, including lymphocytes, macrophages, or plasma cells or both, and increased fibrous tissue. 13 Dogs with a histologic diagnosis of CH were included if medical records were available for analysis and if the outcome could be assessed either from the record or by follow-up conversations with the owner or referring veterinarian. Dogs being treated with known hepatotoxic drugs, such as phenobarbital or carprofen, or had a confirmed diagnosis of infectious disease were excluded. Data obtained from medical records at initial presentation included signalment, physical examination findings, clinical signs, diagnostic tests, and imaging evaluations. Diagnostic tests included the results of serum biochemical analyses, CBCs, coagulation profiles, urinalysis, hepatic function tests, and any ancillary testing done to determine possible etiologic factors, such as serologic titers for infectious disease or titers for immune markers such as antinuclear antibodies. Hepatic biopsies were performed either percutaneously with ultrasound guidance or via wedge biopsy at exploratory laparotomy. Trichrome stain for assessment of fibrous tissue content and rhodanine stains for copper were done on all tissue for which paraffin blocks were still available. All liver samples were reviewed

2 34 Shih et al by a single pathologist (JHK). A histopathologic scoring system based on the Knodell scores used in human hepatology 14 and previously used to score canine hepatic lesions 15 was used to grade and stage the biopsy specimens and copper accumulation was scored by examination of rhodanine stains (see Appendix 1) Owners or referring veterinarians were contacted for follow-up data, including current medications and diet, survival time, and, if applicable, cause of death. A clinical scoring system was devised based on the Child-Pugh score, a scoring system used to assess disease severity and to predict survival in human patients with chronic hepatic disease. 19 The scoring system (see Appendix 2) takes into account whether the animal presents with clinical signs, ascites, hypoglobulinemia or hepatic encephalopathy, the degree of hypoalbuminemia or hyperbilirubinemia, and the extent to which the partial prothrombin time (PTT) is prolonged. Data are presented as median (range). The x 2 test was used to assess the relation between short-term survival (,2 months) and the presence of clinical signs and clinicopathologic or histopathologic abnormalities. Nonparametric continuous data (survival time) were compared with categorical data by use of a Mann Whitney U-test. The Spearman rank correlation was used to assess a correlation between 2 sets of ordinal or continuous data. A P value,.05 was considered significant. All statistical analyses were performed by using a commercial statistical software. b To determine if a breed predilection for CH existed for Labrador Retrievers in our hospital, the incidence of CH in Labradors Retrievers in our hospital (number of Labrador Retrievers diagnosed with CH from 2000 to 2005 per total number of Labrador Retriever admissions during this time period) was compared with the overall incidence of CH in all breeds of dogs (number of cases of CH seen between 2000 and 2005 per number of total admissions over the same time period.) Results Thirty Labrador Retrievers were diagnosed with CH. Six cases were excluded because of identification of infectious etiology (Ehrlichia equi, n 5 1), treatment with known hepatotoxic drugs (phenobarbital, n 5 1; carprofen n 5 2; chemotherapy agents, n 5 1), or concurrent hepatic neoplasia at the time of diagnosis (hepatic adenoma, n 5 1), leaving 24 dogs in the study. The incidence of CH in Labrador Retrievers over the course of the study period was 1.2%, whereas the incidence in other breeds was 0.7%. This difference was statistically significant (P 5.001, x 2 test). Signalment, History, Clinical Signs, and Physical Examinations The median age at diagnosis was 9.3 years (range, years). The sex distribution was 11 spayed females, 11 castrated males, and 2 sexually intact males. Seven dogs had a history of otitis externa, and 3 had allergic inhalant dermatitis. Three dogs had a prior diagnosis of endocrine disease (diabetes mellitus/hyperadrenocorticism, n 5 1; hypothyroidism, n 5 2). Two dogs had a history of a seizure disorder but were not currently receiving medication, and 1 dog had idiopathic megaesophagus. Eight dogs had been diagnosed with osteoarthritis by the local veterinarian, and all these dogs were being treated with intermittent nonsteroidal anti-inflammatory drug (NSAID) therapy (aspirin products, n 5 6; deracoxib, b n 5 2). No dogs had been on topical or oral corticosteroids for the 2 months preceding presentation. Clinical signs included decreased appetite (n 5 16), vomiting (9), lethargy (8), weight loss (6), diarrhea (2), and polyuria/polydipsia (2). Four dogs were asymptomatic upon presentation and referred only for increases in liver enzymes (median increase in time before referral, 7 weeks; range, weeks). Six dogs presented for problems unrelated to their liver disease: megaesophagus/pneumonia because of myasthenia gravis (n 5 1), splenic mass [hemangiosarcoma (1), hematoma (1)], sudden acquired retinal degeneration (1), necrotic retroperitoneal lipoma (1), and gastric dilation (1). Findings on physical examination included icterus (n 5 9), hyperthermia (3), cranial abdominal organomegaly (2), and abdominal pain (2). The median body condition score was 6 of 9 (range, 2 8). Clinicopathologic Findings Serum biochemical analyses were performed on all dogs at the time of diagnosis. The median and the range of values in all dogs tested were as follows. In creased serum alkaline phosphatase (ALP) activity was present in 21 dogs (median, 398 U/L; range, U/L), increased alanine aminotransferase (ALT) activity in 20 dogs (median, 794 U/L; range, U/L), increased aspartate aminotransferase (AST) activity in 20 dogs (122 U/L; range, U/L), and increased gammaglutamyl transpeptidase activity in 9 dogs (median, 11 U/L; range, 2 86 U/L). Activity of a single liver enzyme was high in 4 dogs, activities of 2 liver enzymes were high in 3 dogs, activities of 3 liver enzymes were high in 8 dogs, and 9 dogs had increases in all 4 liver enzymes. Eleven dogs were hyperbilirubinemic (median, 1.65 mg/dl; range, mg/dl), 5 dogs were hypoalbuminemic (median, 2.4 g/dl; range, g/ dl), 6 had increased cholesterol concentrations (median, 400 mg/dl; range, mg/dl), and 1 dog had low cholesterol. High blood urea nitrogen (BUN) and creatinine concentrations were noted in 5 cases, only 1 of which was attributed to primary renal disease by a concurrent finding of isosthenuria. One low BUN concentration was observed. Four dogs had low (median 2.1 g/dl; range g/dl), and 1 dog had high serum globulins. Coagulation was assessed in 21 dogs. Seven dogs had prolonged partial thromboplastin times (PTT; median, 11.8 seconds; range, seconds). Nine dogs had prolonged prothrombin time (PT; median, 9.0 seconds; range, seconds). Fibrinogen concentrations were determined in 9 dogs and 6 were low (median, 100 mg; range,, mg). Pre- or posttotal serum bile acid concentrations were increased in 2 of the 4 cases. One of 6 dogs tested was hyperammonemic. Paired leptospirosis titers measured 2 weeks apart in 9 dogs were negative. Serum antinuclear antibody titers were negative in the 3 dogs tested. A CBC was performed on all dogs. The median white blood cell (WBC) count was /ml (range, /ml). Nine dogs had an increased WBC

3 Chronic Hepatitis in Labradors 35 (median, /ml; range, /ml), and 2 were neutropenic. Two dogs had a left shift, 7 had lymphopenia and 2 had a monocytosis. The median hematocrit was 46% (range, 26 58%). Seven dogs were anemic (median, 31%; range, 23 35%). Four dogs had thrombocytopenia (median, /ml; range, /ml), and 1 dog had a thrombocytosis. A complete urinalysis was available for 14 dogs. Three dogs had transient glucosuria without hyperglycemia. One diabetic dog had glucosuria with hyperglycemia. Two dogs had proteinuria; in 1 dog, the cause was likely from a urinary tract infection, and, in the other dog, the proteinuria was not present in a urinalysis 2 months later. Seven dogs were bilirubinuric. Urine cultures were performed for 5 dogs; only 1 was positive (Escherichia coli). Based on the dogs presenting clinical signs and the results of clinicopathologic testing, a clinical score was generated for each dog (see Appendix 2). The median clinical score was 3 (range, 0 8), with the range of possible clinical scores being 0 to 13. Diagnostic Imaging Eight of 15 thoracic radiographs taken were normal. Abnormalities noted were an increased interstitial pattern (n 5 2), increased bronchoalveolar markings (2), and pleural effusion (2). Ten dogs had survey abdominal radiographs taken. Two dogs had decreased abdominal detail; 1 dog each had an abdominal mass, hepatomegaly, splenomegaly, prostatomegaly, and gastric distention. Ultrasonography was performed on 21 dogs. Changes in hepatic echogenicity were present in 16 of 21 dogs and included inhomogeneous (n 5 8), hypoechoic (5), or hyperechoic (3) parenchyma. Nine dogs had one or more nodules in the liver (hypoechoic [5], hyperechoic [2], isoechoic [2]). Abnormal liver size was noted in 6 dogs (microhepatica [5], hepatomegaly [1]) and 2 dogs had an irregular border to their liver. Abdominal effusion was present in 2 dogs. The liver was normal in 3 dogs. Splenic abnormalities were noted in 7 dogs, 4 had splenomegaly, 3 had abnormal foci (hypoechoic [2], hyperechoic [1]), and 3 had masses associated with the spleen (isoechoic [2], mixed echogenicity [1]). Nine dogs had hyperechoic renal cortices, and 1 had a cyst in the renal cortex. Histopathology Liver biopsies were performed on all dogs. Two to 4 cores were performed percutaneously with ultrasound guidance by using either a 16 (n 5 2) or 18 (n 5 14) gauge biopsy needle. In 7 dogs, wedge biopsy specimens were obtained at surgery, and 1 dog had hepatic tissue obtained at necropsy. All dogs had mild-to-moderate infiltrates of lymphocytes or macrophages, which were most prominent in the portal areas. Thirteen of 24 dogs also had a neutrophilic component. The median score for inflammatory changes was 2.0 (range, 1 3). Twenty one of 24 dogs had degenerative hepatocellular changes of either mild hydropic change (75%) or necrosis (40%). The median score for degenerative changes was 1.0 (range, 0 3). Combining the score for inflammation and degenerative changes resulted in a median histologic grade of 3.5 (range, 1 6). Twenty one of 24 dogs had evidence of increased fibrous tissue on hematoxylin and eosin staining. Trichome staining was done on 17 of 24 biopsy specimens, with a median score of 3 (range, 0 4). Six dogs had bridging fibrosis, and 4 dogs had cirrhosis. Copper staining with rhodanine was performed in 17 of 24 cases. Positive staining was observed in 15 of 17 biopsy specimens, with a median score of 2.0 (range, 0 3). The distribution of copper was multifocal in 15 of 16 dog and diffuse in 1. Excess copper was located in all 3 zones in 8 dogs and primarily centrilobular or portal in 3 and 5 dogs, respectively. Cultures were performed on hepatic biopsy samples in 13 of 24 dogs, and 3 were positive (one each of Enterobacter cloacae, Staphylococcus intermedius, and an unidentified gram-positive organism). Treatment After diagnosis, dogs were treated with a variety of medications for their primary liver disease. Eight dogs were given ursodeoxycholate (15 mg/kg PO q24h), and 6 dogs were prescribed with immunosuppressive therapy (prednisone [n 5 4], azathioprine [2]). Nine dogs were treated with antibiotics. Therapy to prevent gastric ulceration was initiated in 11 cases (famotidine [n 5 8], sucralfate [3]). Three dogs were treated for hepatic encephalopathy (lactulose [n 5 2], neomycin [1]). Two dogs were treated with hepatoprotective agents (Sadenosylmethionine [n 5 1], milk thistle [1]). Survival The median survival time of dogs was 374 days (range, days). Eleven dogs died within 2 months, and 13 dogs survived more than a year after diagnosis. Ten dogs are still alive. Of the 14 dogs who died, 10 died or were euthanized because of liver-related complications, 2 died from complications of an associated megaesophagus/pneumonia, 1 from metastatic splenic hemangiosarcoma, and 1 from renal failure. Statistical analysis was conducted on 20 dogs: 10 who were still alive and 10 who died from liver-related causes. The clinical score was negatively correlated, with an overall survival time (r , P 5.030; Fig 1A) and positively correlated with histopathologic staging (r , P 5.049; Fig 1B). Dogs who died within 2 months of diagnosis were more likely to have a prolonged PT (P 5.013) and thrombocytopenia (P 5.041). Dogs with anorexia (P 5.049), serum hypoglobulinemia (P 5.045), or a prolonged PTT (P 5.033) had a shorter overall survival time than those without these abnormalities. No significant associations (P..4) were found between overall survival and histopathologic grade, degree of serum liver enzyme evaluation, hyperbilirubinemia, serum albumin, or blood glucose. There was a tendency (P 5.083) for histologic stage to be negatively correlated with survival time.

4 36 Shih et al Fig 1. Relation between the clinical score and survival (A) (n 5 20) and histopathologic stage (B) (n 5 17) in Labrador Retrievers diagnosed with CH. Discussion Labrador Retrievers are predisposed to develop CH that progresses to hepatic failure. The hepatopathy affects middle-aged to older dogs and, although an earlier study suggested a female predisposition, there was an approximately equal number of male and female dogs in this study. 12 Most dogs in the current study presented with vague clinical signs (eg, decreased appetence, vomiting, lethargy, weight loss), but some (17%) were asymptomatic except for increases in serum liver enzymes. Clinicopathologic findings were consistent with hepatic disease. Increases in one or more serum enzyme indicative of active hepatobiliary disease (ALT, AST, or ALP) occurred in all dogs. Biochemical tests of functional hepatic reserve, such as serum hyperbilirubinemia or hypoalbuminemia were abnormal in only 45% and 21% of dogs, respectively. Total serum bile acids, performed in only 4 dogs, were abnormal in 2. Although 87% of the dogs had some ultrasonographic abnormality in the liver, the changes were largely nonspecific and compatible with multiple pathologic processes. Based on the results of this study, increased serum enzymes represent the best initial screening test for the presence of CH in Labrador Retrievers. Confirmation of a CH in Labrador Retrievers requires evaluation of hepatic histopathology. Typical changes on histopathology included varying amounts of lymphocytic and histiocytic inflammation primarily centered on portal areas with frequent nests of lipid and pigment-laden macrophages and multifocal, random hydropic degeneration, and necrosis. Histologic grade (the amount of inflammatory and degenerative change) as determined from hematoxylin and eosin staining was moderate to severe (grading score.4) in over 50% of the dogs. Histologic stage (as determined by evaluation of trichome stains) revealed that 76% of the dogs had moderate to severe (staging score.3) deposition of fibrous tissue at the time of diagnosis. Regardless of the extent of clinical signs, hepatic biopsy of all dogs in this study revealed significant liver disease. Thus, the lack of clinical signs in Labradors Retrievers with increased serum liver enzymes should not discourage veterinarians from pursing additional diagnostics to determine if CH exists. Neither histologic stage nor grade was correlated with survival time. Even the presence of cirrhosis was not associated with a shorter survival time. Indeed, in the 4 cirrhotics identified, 2 died within 6 months, but 2 are still alive 2 years after diagnosis. However, in previous retrospective studies of CH that included multiple breeds of dogs, bridging fibrosis (stage 3), 20 necrosis severity, and the presence of cirrhosis (stage 4) 21 were associated with survival times of less than 1 month. Reasons for the discrepancies between these studies and ours include the possibility of a more slowly progressive disorder in Labrador Retrievers or an earlier diagnosis with more aggressive interventional therapy in our study population. In addition, differences could have arisen from the sampling error that accompanies percutaneous hepatic biopsies or from interobserver variation between the 3 different pathologists evaluating the biopsy samples in these studies. No potential etiologic factor for CH was identified in this group of Labrador Retrievers. The breed association suggests a possible genetic predisposition to CH. In humans, genetic predispositions for chronic hepatitis include inborn errors of copper balance, increased susceptibility to autoimmune disease, infectious disease or drug toxicosis, iron storage disease (hematochromatosis), and alpha 1 antitrypsin deficiency. 11 Disorders of copper metabolism occur in Bedlington Terriers, West Highland White Terriers, and Dalmations. 3 6 These disorders are diagnosed by finding increased copper (.2000 ppm) by quantitative analysis, preferential copper accumulation in hepatocytes around the central vein (zone 3 of the liver lobule), or response to treatment with copper chelating drugs or both, such as penicillamine or trientine. 3,7,18 In the current study, no quantitative copper analysis was done, and no dog was treated with copper-chelating agents. Available hepatic biopsy material was stained with rhodanine, however, which permits semiquantitative analysis of copper stores and assessment of staining patterns ,22 Fifteen of 17 hepatic biopsy specimens revealed mild-to-moderate copper accumulation within hepatocytes or macro-

5 Chronic Hepatitis in Labradors 37 phages or both, but no distinctive pattern of preferential accumulation of copper in centrolobular areas was noted. Because many dogs in this study had late stage disease, it is difficult to say what the initial pattern of zonal distribution of copper might have been. In humans, cholestatic liver disease itself can result in mild-to-moderate increases in hepatic copper content. 23,24 It has been postulated that the same may occur in dogs, thus the copper accumulation in the liver in this study might represent a cause or an effect of CH. A recent preliminary report in 15 European Labrador Retrievers d with CH found increased copper stores, with preferential accumulation in hepatic zone 3. The role of copper as an etiologic factor in chronic hepatitis in Labrador Retrievers clearly requires further investigation. Other potential etiologic factors were examined in this study. Several dogs were receiving intermittent therapy with NSAIDs at the time of diagnosis. Although NSAIDs can be chronic hepatotoxins, it was impossible to establish a temporal association of drug use with the development of CH. No infectious agents were linked to the hepatopathy. All leptospirosis titers done (9/24) were negative. Further testing for other organisms incriminated in CH in dogs, such as Bartonella, Helicobacter, and canine adenovirus, were not done. Thirty-seven percent of the dogs in this study had concurrent diseases associated with immune aberrations (eg, atopy, glomerulonephritis, megaesophagus, hypothyroidism), but whether this is a coincidence or indicative of multiple immune disorders, as can be seen in human autoimmune hepatitis, is unknown. Four dogs tested for anti-nuclear antibody titers were negative. Clearly, further studies into potential etiologic factors for this breed-associated hepatopathy are necessary. Survival time in this group of dogs ranged from 1 day to 8 years, with a median of approximately 1 year. This survival time is compatible with a retrospective study that looked a CH in multiple breeds of dogs (mean survival of approximately 11 months) 21 but is shorter than that reported in a larger retrospective series (mean survival of approximately 19 months). 20 Many dogs in this study were given either immunosuppressive or hepatoprotective therapy (16/24) at the time of diagnosis. Although we were unable to detect a statistically significant effect of this treatment on survival, the power of this retrospective study to determine the effect of random treatment protocols is very low. Several variables were associated with survival in Labrador Retrievers with CH. Dogs with short-term survival (ie, those that survived,2 months) were more likely to have a prolongation in PT and thrombocytopenia than dogs with long-term survival. A previous retrospective study also linked prolongation of PT to poor short-term survival (defined as,1 week). 20 In that particular study, hypoglycemia and hypoalbuminemia were also negative prognostic factors. 20 We did not find that serum albumin or blood glucose concentrations were related to survival time. Thrombocytopenia may be more common in the dogs with short-term survival, because it reflects hepatic synthetic failure, with decreased synthesis of thrombopoietin. It may also reflect disseminated intravascular coagulation or bleeding secondary to a coagulopathy. All of the 4 dogs with thrombocytopenia had a least 1 additional coagulation abnormality (decreased fibrinogen in 2, increased PT or PTT in 3, and increased fibrin degradation products in 2), although none had clinical evidence of a bleeding disorder. The presence of anorexia, prolongation of PTT, or serum hypoglobulinemia was associated with shorter overall survival time. The association with anorexia could indicate the occurrence of more severe complications in these animals, such as gastric ulceration or subclinical hepatic encephalopathy that affect appetite or reflect the fact that anorectic dogs were more likely to be euthanized. A link between anorexia and the owner s decision to euthanize has already been established in cardiovascular disease in dog. 25 An association between low serum globulin and survival was seen in another retrospective study that looked at serum electrophoresis in dogs with CH. 26 In that study, terminal liver disease was associated with a profound decrease in alpha-globulins. 26 This may be indicative of a severe defect in hepatic synthetic function, because the liver is responsible for synthesis of alpha and beta globulins. A clinical score that incorporates the presence of clinical signs associated with hepatic failure (ie, ascites, hepatic encephalopathy, anorexia, polyuria/polydipsia) and biochemical evidence of decreased hepatic synthetic function (ie, serum hypoglobulinemia, degree of increase of bilirubin, decrease in albumin, and prolongation of PTT) was significantly higher in dogs with poor shortterm survival and was correlated with overall survival time. The clinical scoring was devised based on the Child-Pugh score used to determine the prognosis and predict survival in human patients with hepatic disease. 14,19 The Child-Pugh score incorporates hyperbilirubinemia, hypoalbuminemia, PT prolongation, the response to therapeutic intervention in ascites, and the degree of encephalopathy. The score used in the current study replaced PT with PTT, because it had a stronger correlation with overall survival both in this study and in an earlier retrospective study of canine CH. 20 Likewise, serum hypoglobulinemia was included in the clinical score because it was associated with poor survival in this study and others. 26 This scoring system gives a range from 0 to 13, with 13 being the most severe. The median score assigned to dogs in this study was 2.9, with a range of 0 8. With more validation, this clinical scoring system may prove useful as a noninvasive tool to be used along with careful clinical assessment of patients to predict prognosis or evaluate response to therapy or both. It would decrease reliance on prognostic information gleaned from hepatic biopsy, which is fraught with sampling and interpretative error 17 and permit easy comparison of cases seen at different practices or institutions. There are several limitations, however, inherent in the establishment of a clinical scoring system such as the one proposed First, the components are selected empirically, and each is given equal weight. While factors were

6 38 Shih et al selected that reflect hepatic synthetic or excretory function or have been revealed to be prognostic in other retrospective studies, they may not be independent and might be influenced by factors unrelated to hepatic disease. The arbitrary use of cutoff values is another limitation. We have no evidence that our cutoffs are optimal for defining significant changes in mortality or that mortality risk increases linearly. The scoring system also does not take into account that etiology may influence survival. Last, we entered patients in at the time of presentation for CH rather than at some defined stage of disease as is routinely done with the Child-Pugh score in humans. Other scoring systems used in human hepatology (Mayo scores), 27 however, enter patients at different stages and still provide valid survival information. Clearly, the proposed scoring system will have to be validated prospectively in a large group of dogs, representing several breeds and geographical locations, before widespread clinical application. This study describes a breed-related CH that occurs in Labrador Retrievers that progresses to hepatic failure. This occurrence of this syndrome should be considered in middle-aged to older Labrador Retrievers who present with increases in serum liver enzymes and can be confirmed with evaluation of hepatic histopathology. Further studies to determine a potential etiology, including quantitative copper analysis and testing for immune aberrations and infectious organisms is warranted so that appropriate interventional therapy to slow progression can be identified. Footnotes a Hardy RM. Chronic hepatitis in cocker spaniels Another syndrome? Proceedings. 11th Ann Am College Vet Intern Med Forum 1993; b SPSS 13.0, SPSS, Chicago, IL c Dermaxx, Novartis Animal Health, Greensboro, NC d Hoffman G, van den Ingh TSGAM, Bode P, Rothuizen J. Copper associated chronic hepatitis in Labrador retrievers: 15 clinical patients and their families. J Vet Intern Med 2006;20:753A (abstract) References 1. Crawford MA, Schall WD, Jensen RK, et al. Chronic active hepatitis in 26 Doberman Pinschers. J Am Vet Med Assoc 1985;187: Haywood S, Rutgers HC, Christian MK. Hepatitis and copper accumulation in Skye Terriers. Vet Pathol 1988;28: Hultgren BD, Stevens JB, Hardy RM. Inherited chronic progressive hepatic degeneration in Bedlington Terriers with increased copper concentrations: Clinical and pathologic observations and comparison with other copper associated liver diseases. Am J Vet Res 1986;47: Thornburg LP, Rottinghaus G, Dennis G, et al. The relationship between hepatic copper content and morphological changes in the liver of West Highland White Terriers. Vet Pathol 1996;33: Twedt D, Sternlieb I, Gilbertson SR. Clinical, morphologic and chemical studies on copper toxicosis of Bedlington Terriers. J Am Vet Med Assoc 1979;175: Webb CB, Twedt D, Meyer DJ. Copper associated liver disease in Dalmations: A review of 10 dogs ( ). J Vet Intern Med 2002;16: Fuentealba IC, Aburto EM. Animal models of copperassociated liver disease. Comp Hepatol, Available at: http// Accessed October 24, Mandiger PJ, van den Ingh TS, Spee B, et al. Chronic hepatitis in Doberman Pinschers: A review. Vet Q 2004;26: Thornburg LP. Histomorphological and immunohistochemical studies of chronic active hepatitis in Doberman Pinschers. Vet Pathol 1998;35: Sevelius E, Andersson M, Jönsson L. Hepatic accumulation of alpha-1-antitrypsin in chronic liver disease in the dog. J Comp Path 1994;111: Watson PJ. 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7 Chronic Hepatitis in Labradors Christensen E. Prognostic models including the Child-Pugh, MEDL and Mayo risk scores Where are we and where should we go. J Hepatol 2004;41: Durand F, Valla D. Assessment of the prognosis of cirrhosis: Child-Pugh versus MELD. J Hepatology 2005;S Kamath P, Wiesner R, Malinshoc M, et al. A model to predict survival in patients with end stage liver disease Hepatology 2001;33: Appendix 1. Histologic scoring for stage, grade, and copper accumulation. Histologic Scoring for Rhodanine Copper Staining 0 5 Absence or rare copper positive cell 1 5 Few random copper positive cells 2 5 Moderate numbers of copper positive cells 3 5 Many copper positive cells in all zones The score for rhodanine staining of normal canine 3, liver has been reported as 0. Histopathology (Hematoxylin and eosin [H&E] Grading System Inflammation and Degeneration (both are scored separately) 0 5 Absent 1 5 Mild 2 5 Moderate 3 5 Severe Histopathology (H&E, Trichome) Staging System 0 5 Absent 1 5 Mild: Fibrous tissue expansion limited to the portal tracts 2 5 Moderate: Fibrous tissue expansion beyond the limiting plate 3 5 Severe: Bridging fibrosis, portal-portal or portal-central linkage 4 5 Cirrhosis: Bridging fibrosis with evidence of regenerative nodules Appendix 2. Clinical Scoring System One point each for the presence of ascites, serum hypoglobulinemia, hepatic encephalopathy (increased blood ammonia concentration or presence of diffuse cerebral neurologic signs responsive to lactulose, metronidazole/neomycin and protein restriction or both), and clinical signs associated with liver disease (polyuria/ polydipsia, anorexia, lethargy, vomiting). Additional points were assigned as indicated below, based on the degree of hypoalbuminemia and hyperbilirubinemia, and the extent to which partial prothrombin time was prolonged. The full range of the scale is Points Bilirubin (mg/dl) Albumin (mg/dl) PTT 3 ULN , 0.06, , 4.00, , PTT, partial thromboplastin time; ULN, upper limit of normal.