Ductal Plate Malformation in the Liver of Boxer Dogs: Clinical and Histological Features

BILIARY DUCTAL PLATE MALFORMATION WITH SECONDARY PORTAL HYPERTENSION AND MULTIPLE ACQUIRED SHUNTS IN A LITTER OF AMUR TIGERS (PANTHERA TIGRIS ALTAICA)

Congenital abnormalities in tigers (Panthera tigris) are infrequently reported but have included ectrodactyly, cataracts, and vestibular disease. Primary hepatic disease has been documented in multiple nondomestic felid species but is considered uncommon in tigers. To the authors' knowledge, there are no previous reports of congenital abnormalities of the liver in tigers. In May 2022, two male Amur tiger cubs (Panthera tigris altaica) were born at a zoological institution via cesarean section to address dystocia, following the natural birth of a female cub. Between two and six months of age, all three cubs developed progressive lethargy, inappetence, and neurological signs consistent with hepatic encephalopathy, including obtundation and ataxia. In all three cases, serum biochemical values revealed progressive, marked elevations in hepatic enzyme levels with reduction in hepatic synthetic products (albumin, urea, cholesterol). Computed tomographic imaging showed a large cluster of aberrant tortuous vessels craniomedial to the left kidney in all three tigers, consistent with acquired extrahepatic portosystemic shunts. Histologic examination of the livers identified biliary ductal plate malformations. This report details the presentation, clinical findings, diagnoses, and therapeutic interventions attempted in three Amur tiger cubs with biliary ductal plate malformation and subsequent portal hypertension with multiple acquired portosystemic shunts, an unusual abnormality not previously reported in non-domestic felids.

Histopathology and molecular pathology confirmed a diagnosis of atypical Caroli's syndrome: a case report

Caroli's syndrome is a congenital disease characterized by dilation of intrahepatic bile ducts and congenital hepatic fibrosis. It is a rare condition in clinical work. Typically, the diagnosis of this disease is confirmed through medical imaging. Here, we report a case of atypical Caroli's syndrome in a patient who presented with recurrent upper gastrointestinal tract bleeding. The patient underwent imaging examinations, liver biopsy and whole exome sequencing. The results of the imaging examination were non-specific. However, with the aid of pathological examination, the patient was diagnosed with Caroli's syndrome. In conclusion, for cases where the imaging presentation of Caroli's syndrome is inconclusive, an accurate diagnosis should rely on pathology. By discussing this specific case, our aim is to enhance readers' understanding of this disease, provide valuable information that can aid in the early detection and appropriate management of Caroli's syndrome, ultimately improving patient outcomes.

Bile duct hamartoma in a dog

An 11-year-old female Collie presented with a significantly increased abdominal circumference. Computed tomography of the abdomen revealed that the left lateral lobe of the liver contained a large mass, which was excised via laparotomy. Histologically, many small, dilated, cystic luminal structures were anastomosed and connected to a net-like structure. Immunohistochemistry revealed cytokeratin 19-immunopositive areas, representing bile duct structures in the cystic lumen. Based on these results, the tumour was diagnosed as a bile duct hamartoma. To our knowledge, this is the first report of a bile duct hamartoma in a dog.

CT features of divisional bile ducts in healthy Labrador Retrievers

Computed tomography (CT) is increasingly being used for the study of gallbladder and bile duct diseases. The first step in interpreting CT findings is understanding the cross-sectional anatomy of the structures involved, but there are no published studies describing the CT features of the divisional bile ducts. In dogs, anatomic studies report two common patterns including three or four divisional bile ducts. The aim of this retrospective, descriptive, anatomical study was to describe the size and pattern of the visible divisional bile ducts, based on their location and extension, using contrast-enhanced CT in a group of Labrador Retrievers without evidence of hepatobiliary diseases. The correlation between the biliary duct number and dimensions, and the visceral fat area percentage (VFA%) was also evaluated. The right lateral divisional duct (RLD) was visualized in four of 40 dogs, the left lateral divisional duct (LLD) in nine of 40 dogs, and in 17 of 40 dogs, both were simultaneously visualized. In 10 of 40 dogs, the RLD and LLD were not highlighted. When visible, the RLD has a median diameter of 0.23 cm and a median length of 0.82 cm. The LLD has a median diameter of 0.23 cm and a median length of 2.72 cm. The median diameter of the common bile duct before and after the insertion of divisional bile ducts was 0.23 and 0.25 cm, respectively. No correlation with the VFA% was found. At least one of the divisional bile ducts could be visualized using contrast-enhanced CT in the majority of sampled dogs (75%) .

Hepatic copper accumulates in ferrets with and without hepatobiliary disease

OBJECTIVE

To determine hepatic copper concentrations and zonal distribution in ferrets with and without hepatobiliary disease, validate rhodanine-based qualitative copper scoring and digital copper quantification in ferret hepatic samples, and ascertain whether clinical features predicted copper accumulation.

ANIMALS

34 ferrets, including 7 with necroinflammatory disease, 5 with hepatocellular carcinoma, 13 with non-necroinflammatory disease, and 9 with no hepatobiliary disease.

PROCEDURES

Rhodanine-based digital copper quantification was validated by use of liver dually measured by atomic absorption spectroscopy and digital scanning (R2 = 0.98). Clinical features and hepatic copper scores and concentrations (dry weight liver) were compared between groups. Zonal copper distribution was determined.

RESULTS

Hepatic copper concentration was strongly correlated with copper scores (ρ = 0.88). Ferrets with hepatobiliary disease were significantly older and had significantly higher serum alkaline phosphatase and γ-glutamyltransferase activities and creatinine concentrations. Centrilobular copper accumulated in 23 of 34 (64%) ferrets with (n = 15) and without (8) hepatobiliary disease. Median copper concentrations were not significantly different between ferrets with and without hepatobiliary disease but were significantly higher within neoplastic hepatic tissue in ferrets with hepatocellular carcinoma. Hepatic copper concentrations exceeded feline (> 180 µg/g) and canine (> 400 µg/g) reference limits in 19 and 9 ferrets, respectively. Hepatic copper > 1,000 µg/g occurred in 5 ferrets with and 2 without hepatobiliary disease. Clinical features did not predict copper accumulation.

CLINICAL RELEVANCE

Rhodanine-based digital copper quantification and qualitative copper scoring discerned liver copper accumulation in ferrets. Ferrets with and without hepatobiliary disease displayed a propensity for centrilobular hepatic copper accumulation of uncertain clinical importance. Clinical and clinicopathologic features could not exclusively implicate pathologic copper accumulation.

A case of a congenital umbilicobiliary fistula associated with gallbladder agenesis in a dog

Congenital biliary tree malformations are rarely described in the veterinary field. A congenital umbilicobiliary fistula associated with gallbladder agenesis was reported here for the first time in a 1-year-old male French bulldog. After contrast study, abdominal ultrasound, and histopathology, we concluded that the umbilicobiliary fistula was an aberrant duct that originated directly from the expected location of the cystic duct and gallbladder. The clinical case was treated surgically through ligation and excision of the aberrant duct before entering the common bile duct. The recovery and long-term follow-up were uneventful. The pathophysiology of biliary congenital malformations is discussed, along with clinical considerations that should be considered in similar future cases.

Bacterial culture and immunohistochemical detection of bacteria and endotoxin in cats with suppurative cholangitis-cholangiohepatitis syndrome

OBJECTIVE

To characterize the frequency and type of bacterial infection by culture- and immunohistochemical (IHC)-based methods and determine the impact of infection on clinical features and survival time in cats with suppurative cholangitis-cholangiohepatitis syndrome (S-CCHS).

ANIMALS

168 client-owned cats with S-CCHS (cases).

PROCEDURES

Clinical features, bacterial culture results, culture-inoculate sources, and survival details were recorded. Cases were subcategorized by comorbidity (extrahepatic bile duct obstruction, cholelithiasis, cholecystitis, ductal plate malformation, biopsy-confirmed inflammatory bowel disease, and biopsy-confirmed pancreatitis) or treatment by cholecystectomy or cholecystoenterostomy. Culture results, bacterial isolates, Gram-stain characteristics, and IHC staining were compared among comorbidities. Lipoteichoic acid IHC staining detected gram-positive bacterial cell wall components, and toll-like receptor expression IHC reflected pathologic endotoxin (gram-negative bacteria) exposure.

RESULTS

Clinical features were similar among cases except for more frequent abdominal pain and lethargy in cats with positive culture results and pyrexia, abdominal pain, and hepatomegaly for cats with polymicrobial infections. Bacteria were cultured in 93 of 135 (69%) cats, with common isolates including Enterococcus spp and Escherichia coli. IHC staining was positive in 142 of 151 (94%) cats (lipoteichoic acid, 107/142 [75%]; toll-like receptor 4, 99/142 [70%]). With in-parallel interpretation of culture and IHC-based bacterial detection, 154 of 166 (93%) cats had bacterial infections (gram-positive, 118/154 [77%]; gram-negative, 111/154 [72%]; polymicrobial, 79/154 [51%]). Greater frequency of bacterial isolation occurred with combined tissue, bile, and crushed cholelith inoculates. Infection and gram-positive bacterial isolates were associated with significantly shorter long-term survival times.

CLINICAL RELEVANCE

S-CCHS was associated with bacterial infection, pathologic endotoxin exposure, and frequent polymicrobial infection in cats. Combined tissue inoculates improved culture detection of associated bacteria.

Clinical features, concurrent disorders, and survival time in cats with suppurative cholangitis-cholangiohepatitis syndrome

OBJECTIVE

To characterize clinical features, comorbidities, frequency of bacterial isolation, and survival time in cats with suppurative cholangitis-cholangiohepatitis syndrome (S-CCHS).

ANIMALS

168 client-owned cats with S-CCHS.

PROCEDURES

Data were prospectively (1980 to 2019) collected regarding clinical features, comorbidities, bacterial infection, illness duration, and treatments. Variables were evaluated for associations with survival time.

RESULTS

Median age of cats was 10.0 years, with no breed or sex predilection observed. Common clinical features included hyporexia (82%), hyperbilirubinemia (80%), lethargy (80%), vomiting (80%), jaundice (67%), weight loss (54%), and hypoalbuminemia (50%). Comorbidities included extrahepatic bile duct obstruction (53%), cholelithiasis (42%), cholecystitis (40%), and ductal plate malformation (44%) as well as biopsy-confirmed inflammatory bowel disease (60/68 [88%]) and pancreatitis (41/44 [93%]). Bacterial cultures were commonly positive (69%) despite prebiopsy antimicrobial administration in most cats. Of surgically confirmed choleliths, diagnostic imaging identified only 58%. Among 55 cats with "idiopathic pancreatitis," 28 (51%) were documented to have transiting choleliths, and 20 had pancreatic biopsies confirming pancreatitis. Cholelithiasis (with or without bile duct obstruction) and cholecystectomy were associated with survival advantages. Survival disadvantages were found for leukocytosis, ≥ 2-fold increased alkaline phosphatase, and hyperbilirubinemia. Cholecystoenterostomy had no survival impact. Cats with ductal plate malformations were significantly younger at diagnosis and death than other cats. Chronic treatments with antimicrobials, S-adenosylmethionine, and ursodeoxycholic acid were common postbiopsy.

CLINICAL RELEVANCE

S-CCHS in cats was associated with bacterial infection and various comorbidities and may be confused with pancreatitis. Surgically correctable morbidities (ie, cholecystitis, cholecystocholelithiasis) and cholecystectomy provided a significant survival advantage.

Relationships between congenital peritoneopericardial diaphragmatic hernia or congenital central diaphragmatic hernia and ductal plate malformations in dogs and cats

OBJECTIVE

To characterize the association between peritoneopericardial diaphragmatic hernia (PPDH) or congenital central diaphragmatic hernia (CCDH) and ductal plate malformations (DPMs) in dogs and cats.

ANIMALS

18 dogs and 18 cats with PPDH or CCDH and 19 dogs and 18 cats without PPDH or CCDH.

PROCEDURES

Evaluation of clinical details verified PPDH or CCDH and survival times. Histologic features of nonherniated liver samples were used to categorize DPM. Immunohistochemical staining for cytokeratin-19 distinguished bile duct profiles per portal tract and for Ki-67-assessed cholangiocyte proliferation. Histologic features of herniated liver samples from PPDH or CCDH were compared with those of pathological controls (traumatic diaphragmatic hernia, n = 6; liver lobe torsion, 6; ischemic hepatopathy, 2).

RESULTS

DPM occurred in 13 of 18 dogs with the proliferative-like phenotype predominating and in 15 of 18 cats with evenly distributed proliferative-like and Caroli phenotypes. Congenital hepatic fibrosis DPM was noted in 3 dogs and 2 cats and renal DPM in 3 dogs and 3 cats. No signalment, clinical signs, or clinicopathologic features discriminated DPM. Kaplan Meier survival curves were similar in dogs and cats. Bile duct profiles per portal tract in dogs (median, 5.0; range, 1.4 to 100.8) and cats (6.6; 1.9 to 11.0) with congenital diaphragmatic hernias significantly exceeded those in healthy dogs (1.4; 1.2 to 1.6) and cats (2.3; 1.7 to 2.6). Animals with DPM lacked active cholangiocyte proliferation. Histologic features characterizing malformative bile duct profiles yet without biliary proliferation were preserved in herniated liver lobes in animals with DPM.

CONCLUSIONS AND CLINICAL RELEVANCE

DPM was strongly associated with PPDH and CCDH. Because DPM can impact health, awareness of its coexistence with PPDH or CCDH should prompt biopsy of nonherniated liver tissue during surgical correction of PPDH and CCDH.

Canine hepatobiliary anatomy, physiology and congenital disorders

The biliary system is an integral component of normal physiologic homeostasis and essential for survival. It acts as a conduit for the removal of detoxified and catabolised compounds as well as aids in fat digestion and absorption. Derangements in this system can have dangerous sequela that are associated with varying degrees of morbidity and mortality. Moreover, abnormalities in development of the biliary system can have varied and unpredictable changes on function and long-term outcome. The aims of this article were to review canine hepatobiliary anatomy, physiology and cholestasis as well as summarise congenital biliary disorders including human corollaries.

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

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

Disparities in hepatic copper concentrations determined by atomic absorption spectroscopy, inductively coupled plasma mass spectrometry, and digital image analysis of rhodanine-stained sections in dogs

OBJECTIVE

To investigate disparities in hepatic copper concentrations determined by atomic absorption spectroscopy (AAS), inductively coupled plasma mass spectrometry (ICP-MS), and digital image analysis of rhodanine-stained sections.

ANIMALS

516 dogs.

PROCEDURES

Medical records of dogs for which hepatic biopsy specimens had been submitted between January 1999 and December 2019 for evaluation of copper content were reviewed. Paired hepatic copper concentrations obtained with digital image analysis and AAS or ICP-MS were compared, and Spearman rank correlation coefficients were calculated to test for correlations between qualitative copper accumulation scores and hepatic copper concentrations. For dogs for which ≥ 4 rhodanine-stained hepatic sections were available, intraindividual variation in copper distribution across hepatic sections was evaluated.

RESULTS

Median hepatic copper concentrations obtained with digital image analysis exceeded concentrations obtained with AAS or ICP-MS. Concentrations were also higher in older dogs (≥ 9 years vs < 9 years), dogs of breeds with a typical body weight ≥ 20 kg (44 lb), and dogs with necroinflammatory changes or uneven copper distribution. Qualitative copper accumulation scores were significantly associated with hepatic copper concentrations; however, the correlation between qualitative score and concentration obtained with digital image analysis (r_s = 0.94) was higher than the correlation between qualitative score and concentration obtained with AAS (r_s = 0.75) or ICP-MS (r_s = 0.57). The coefficient of variation for hepatic copper concentrations obtained with digital image analysis was significantly higher for dogs with higher hepatic copper concentrations.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that spectroscopic-spectrometric analysis of hepatic biopsy specimens commonly underestimated the concentration obtained by digital image analysis of rhodanine-stained sections.

Immunohistochemical evaluation of hepatic progenitor cells in different types of feline liver diseases

Hepatic progenitor cells are periportally resident cells capable of differentiating into mature hepatocytes or cholangiocytes to ensure hepatic regeneration. This reaction is termed a ductular reaction. In the present study, regenerative response of the feline liver to different hepatic diseases was investigated immunohistochemically. Regeneration of the liver through hepatocellular replication and proliferation of progenitor cell compartment were comparatively evaluated. Histological and immunohistochemical stainings were conducted on feline liver samples (n=40) representing various hepatobiliary diseases. Cytokeratin (CK) 7, CK19, Proliferating cell nuclear antigen (PCNA), Ki67, and Human hepatocyte marker 1 (Hep Par-1) were used. The presence of progenitor cells within feline livers was proved, both as passive cells in normal liver and as active cells (ductular reaction) in hepatic lesions. CK7 was found to be a suitable antibody for immunohistochemically detecting feline progenitor cells. In acute events, regeneration was predominantly shaped by the division of hepatocytes. In chronic events and severe acute events, hepatocytes lost their ability to divide and regeneration mainly occurred through progenitor cells. Location of the ductular reaction varied between different hepatic diseases. Parenchymal ductular reaction was detected in fulminant hepatitis, chronic hepatitis, hepatocellular lipidosis and metastatic lymphoma, whereas septal ductular reaction was detected in chronic hepatitis and metastatic lymphoma. Ductular reaction exhibited positive staining for Hep Par-1 in chronic and severe acute events. This study indicates the major role played by hepatic progenitor cells in regeneration of the feline liver. Moreover, it shows how the activation pattern of ductular reaction varies according to the hepatobiliary disease type.

Central prolactin receptor distribution and pSTAT5 activation patterns in breeding and non-breeding zebra finches (Taeniopygia guttata)

The hormone prolactin has many diverse functions across taxa such as osmoregulation, metabolism, and reproductive behavior. In ring doves, central prolactin action is important for parental care and feeding behavior. However, there is a considerable lack of information on the distribution of the prolactin receptor (PRLR) in the avian CNS to test the hypothesis that prolactin mediates these and other functions in other birds. In order to advance this research, we collected brains from breeding and non-breeding zebra finches to map the PRLR distribution using immunohistochemistry. We found PRLRs are distributed widely across the brain, both in hypothalamic sites known to regulate parental care and feeding, but also in many non-hypothalamic sites, including the tectofugal visual pathway, song system regions, reward associated areas, and pallium. This raises the possibility that prolactin has other functions throughout the brain that are not necessarily related to feeding or parental care. In addition, we also stained brains for pSTAT5, a transcription factor which is expressed when the PRLR is activated and is used as a marker for PRLR activity. We found several notable differences in pSTAT5 activity due to the breeding state of the animal, in both directions, further supporting the hypothesis that prolactin has many diverse functions in the brain both within and outside times of breeding. Together, this study represents the first essential step to inform the design of causative studies which manipulate PRLR-expressing cells to test their role in a wide variety of behaviors and other physiological functions.

Hemorrhage and complications associated with percutaneous ultrasound guided liver biopsy in dogs

BACKGROUND

Liver biopsy is often necessary to obtain a diagnosis in dogs with hepatobiliary disease. Hemorrhage after biopsy is a concern.

OBJECTIVE

To describe the extent of hemorrhage and incidence of complications after percutaneous ultrasound guided liver biopsy (PUGLB) in dogs and to examine risk factors for hemorrhage or complications.

ANIMALS

One hundred two client owned dogs with suspected hepatobiliary disease that underwent PUGLB.

METHODS

Medical records were retrospectively reviewed. Using human guidelines, major hemorrhage was defined as an absolute decrease in the PCV (ΔPCV) ≥ 6%. Complications were defined separately as clinically relevant physiologic compromise that necessitated intervention or death. The relationship between ΔPCV and the occurrence of complications and the initial PCV, coagulation variables, serum activity of liver-derived enzymes, serum bilirubin concentration, number of biopsies, biopsy needle gauge, radiologist experience, histological diagnosis, and ultrasound variables were compared.

RESULTS

Before PUGLB, most aberrations in coagulation variables were mild. After biopsy a decrease in PCV occurred in 87/102 (85.3%) dogs. The mean ΔPCV was -7.2% ± 4.5%. Major hemorrhage occurred in 43/102 (42.2%) dogs and complications in 2/102 (1.9%). ΔPCV was significantly positively correlated with PCV before biopsy (r = .47, P = .004). There was no correlation between ΔPCV or complications with any of the variables examined.

CONCLUSION AND CLINICAL IMPORTANCE

Percutaneous ultrasound guided liver biopsy in the population of dogs in the current study, with normal or mild abnormalities in coagulation, results in a high incidence of clinically silent, major hemorrhage (42.5%), but few complications (1.9%).

Agenesis of hepatic lobes in a dog

Agenesis of a hepatic lobe is an extremely rare congenital anomaly and only one dog have been reported in veterinary literature. We encountered a dog with this anomaly diagnosed by Computed tomography (CT) and portography. A two-year-old, 6.9-kg female Shih tzu dog was presented with vomiting and anorexia. The dog had no history of abdominal surgery or trauma. Biochemical analysis showed elevated plasmatic liver enzymes. CT revealed the absence of the liver parenchyma and vascular system of the left lobe, quadrate lobe and papillary process of the caudate lobe. A portosystemic shunt was also observed. The liver parenchyma and vascular system of these lobes were not detected under digital subtraction angiography during laparotomy. Furthermore, the liver parenchyma and vascular system of these lobes were not detected even when the remaining liver volume increased two months after treating the shunt vessel. CT proved itself a good option for antemortally diagnosis of hepatic agenesis in a dog.

A histopathological study on adrenal cysts in ferrets

Adrenal disorders are common in ferrets, but there are few studies on cystic lesions of the adrenal gland. The present study describes pathological and immunohistochemical features of adrenal cysts in eleven ferrets and discusses their histogenesis. In nine of eleven cases examined, which included seven, one, and one right, left, and bilateral cases, respectively, cysts were in the adrenal cortex and lined with epithelial cells. These epithelial cells contained an Alcian blue-negative/PAS-positive material and were positive for cytokeratin (CK) 7. The staining pattern was similar to that of biliary epithelial cells in the ferret. In five of the cases, there were small ducts adjacent to the cysts that were positive for CK7 and CK20 and negative for CK19. Based on the anatomical proximity between the right adrenal and liver, the immunohistochemical features of the small duct cells were comparable to those of hepatic oval cells. These results indicate the possibility that these adrenocortical cysts in the ferret originated from the biliary system. In the other two cases, the cysts lacked an epithelial cell lining, and there were dilated lymphoid vessels around the cysts. These cysts were assumed to have developed in the adrenal medulla, because the cyst wall was positive for glial fibrillary acidic protein and there were adrenal medullary cells positive for synaptophysin in the cyst wall. Therefore, the medullary cysts may have been associated with dilated vasculatures.

Caroli Syndrome in a 6-Year-Old Rottweiler Dog

A 6-year-old entire female rottweiler dog with a recent history of ascites and respiratory disease was submitted for necropsy examination. The dog had been diagnosed ultrasonographically with biliary cysts as a puppy. Grossly, the liver was smaller than expected with an irregular surface. Islands of hepatocytes were separated by bands of fibrosis and many bile ducts were markedly dilated. Histologically, extensive fibrosis extended beyond the limiting plate and into the surrounding hepatic parenchyma and was associated with abundant small bile ducts throughout. In conjunction with the detection of biliary cysts early in life, the gross and histological findings were consistent with a diagnosis of Caroli syndrome. In man, Caroli syndrome is frequently associated with renal and pancreatic cysts; a single renal cyst was identified in this case.

Caroli's-type ductal plate malformation and a portosystemic shunt in a 4-month-old kitten

Case summary

A 4-month-old neutered male Russian Blue kitten had a 4 week history of hypersalivation and failure to thrive. In addition, there was a 2 week history of soft tissue swelling on the ventral abdomen, which had failed to improve with antimicrobial therapy. There were no significant physical examination or neurological deficits on examination; however, the cat had a quiet demeanour for its age. Postprandial bile acids were increased (32 µmol/l; reference interval <25 µmol/l). An abdominal CT scan revealed changes consistent with an extrahepatic portosystemic shunt and inflammation of fat of the ventral abdominal body wall. Surgical biopsy and culture of the subcutaneous swelling identified non-infectious steatitis. Ten weeks following initial presentation, surgical exploration, liver biopsy and ligation of the portosystemic shunt were performed. Liver biopsy was submitted to the Anatomical Pathology Laboratory of Cornell University Animal Health Diagnostic Center, New York, USA. Histopathology revealed a ductal plate malformation (Caroli’s type), as well as changes consistent with a portosystemic shunt.

Relevance and novel information

Ductal plate malformations are rarely described in the veterinary literature. To our knowledge this is the first reported case of Caroli’s-type malformation in a cat. There are no biochemical changes that allow for differentiation of ductal plate malformations from other hepatopathies. Liver biopsy is required for a definitive diagnosis.

Congenital Hepatic Fibrosis in a Purebred Spanish Horse Foal: Pathology and Genetic Studies on PKHD1 Gene Mutations

A 1-month-old Purebred Spanish Horse (PSH) foal presented with progressive hepatic failure culminating in death. Hepatic lesions were consistent with congenital hepatic fibrosis (CHF). Genetic studies in the PKHD1 gene in the affected foal revealed that it was heterozygous for the 2 previously described single-nucleotide polymorphisms (SNPs) linked to CHF in Swiss Franches-Montagnes (SFM) horses. In addition, 2 novel mutations were detected, the foal being homozygous for one of them and heterozygous for the other. Genetic studies in a healthy PSH population ( n = 35) showed a 3-fold higher genotypic frequency for PKHD1 SNP g.49,630,834G>A and a 5-fold higher genotypic frequency for PKHD1 SNP g.49,597,760A>T compared with those reported for SFM horses. SNPs in the PKHD1 gene in CHF-affected SFM horses might not fully explain the CHF observed in the PSH. Other mutations in the PKHD1 gene could play a more important role in the PSH.

Gallbladder Agenesis in 17 Dogs: 2006-2016

Background

Gallbladder agenesis (GBA) is extremely rare in dogs.

Hypothesis/Objectives

To describe the history, clinical signs, diagnosis, treatment, and outcomes of dogs with GBA.

Animals

Seventeen client‐owned dogs with GBA.

Methods

Medical records from 2006 through 2016 were retrospectively reviewed. Dogs were included when GBA was suspected on abdominal ultrasonography and confirmed by gross evaluation. Signalment, clinical signs, clinicopathological data, diagnostic imaging, histopathology, treatment, and outcome were recorded.

Results

Dogs were of 6 different breeds, and Chihuahuas (10 of 17) were most common. Median age at presentation was 1.9 (range, 0.7–7.4) years. Clinical signs included vomiting (5 of 17), anorexia (2 of 17), ascites (2 of 17), diarrhea (1 of 17), lethargy (1 of 17), and seizures (1 of 17). All dogs had increased serum activity of at least 1 liver enzyme, most commonly alanine aminotransferase (15 of 17). Fifteen dogs underwent computed tomography (CT) cholangiography; common bile duct (CBD) dilatation was confirmed in 12, without evidence of bile duct obstruction. Gross evaluation confirmed malformation of the liver lobes in 14 of 17 dogs and acquired portosystemic collaterals in 5 of 17. Ductal plate malformation was confirmed histologically in 16 of 17 dogs. During follow‐up (range, 4–3,379 days), 16 of 17 dogs remained alive.

Conclusions and Clinical Importance

Dogs with GBA exhibit clinicopathological signs of hepatobiliary injury and hepatic histopathological changes consistent with a ductal plate abnormality. Computed tomography cholangiography was superior to ultrasound examination in identifying accompanying nonobstructive CBD distention. Computed tomography cholangiography combined with laparoscopic liver biopsy is the preferable approach to characterize the full disease spectrum accompanying GBA in dogs.

Hepatic Fibrosis in Dogs

Hepatic fibrosis is commonly diagnosed in dogs, often as a sequela to chronic hepatitis (CH). The development of fibrosis is a crucial event in the progression of hepatic disease that is of prognostic value. The pathophysiology of hepatic fibrosis in human patients and rodent models has been studied extensively. Although less is known about this process in dogs, evidence suggests that fibrogenic mechanisms are similar between species and that activation of hepatic stellate cells is a key step. Diagnosis and staging of hepatic fibrosis in dogs requires histopathological examination of a liver biopsy specimen. However, performing a liver biopsy is invasive and assessment of fibrotic stage is complicated by the absence of a universally accepted staging scheme in veterinary medicine. Serum biomarkers that can discriminate among different fibrosis stages are used in human patients, but such markers must be more completely evaluated in dogs before clinical use. When successful treatment of its underlying cause is feasible, reversal of hepatic fibrosis has been shown to be possible in rodent models and human patients. Reversal of fibrosis has not been well documented in dogs, but successful treatment of CH is possible. In human medicine, better understanding of the pathomechanisms of hepatic fibrosis is leading to the development of novel treatment strategies. In time, these may be applied to dogs. This article comparatively reviews the pathogenesis of hepatic fibrosis, its diagnosis, and its treatment in dogs.

Ultrasonographic and clinicopathologic features of segmental dilatations of the common bile duct in four cats

CASE SERIES SUMMARY

This case series documents ultrasonographic and clinicopathologic features of four cats with marked segmental dilatations of the common bile duct (CBD). All cats had additional ultrasonographic changes to the hepatobiliary system, including hepatomegaly, tubular to saccular intra/extrahepatic biliary duct dilatation and biliary debris accumulation. Based on all available data the presence of extrahepatic biliary duct obstruction (EHBDO) was ruled out in 3/4 cases and was equivocal in one case. One cat underwent re-routing surgery to address the CBD dilatation after multiple recurrent infections, one cat was euthanized and had a post-mortem examination and two cats were medically managed with antibiotics, liver protectants, gastroprotectants and cholerectics.

RELEVANCE AND NOVEL INFORMATION

The ultrasonographic features of the CBD in this population of cats were supportive of choledochal cysts (CCs). The maximal diameter of the CBD dilatations exceeded 5 mm in all cases, a sign that has been previously reported to be consistent with EHBDO. In our study, dilatations were segmental rather than diffuse. Given the high morbidity and mortality associated with hepatobiliary surgery in cats, segmental dilatation of the CBD should not prompt emergency surgery. Some cats may respond to medical management. Careful planning for cyst resection was beneficial in one cat. Evaluation of CC morphology (eg, size, location, concurrent intrahepatic anomalies) may assist in selecting cats that could benefit from surgical intervention.

Ultrasonographic and clinicopathologic features of segmental dilatations of the common bile duct in four cats

Case series summary

This case series documents ultrasonographic and clinicopathologic features of four cats with marked segmental dilatations of the common bile duct (CBD). All cats had additional ultrasonographic changes to the hepatobiliary system, including hepatomegaly, tubular to saccular intra/extrahepatic biliary duct dilatation and biliary debris accumulation. Based on all available data the presence of extrahepatic biliary duct obstruction (EHBDO) was ruled out in 3/4 cases and was equivocal in one case. One cat underwent re-routing surgery to address the CBD dilatation after multiple recurrent infections, one cat was euthanized and had a post-mortem examination and two cats were medically managed with antibiotics, liver protectants, gastroprotectants and cholerectics.

Relevance and novel information

The ultrasonographic features of the CBD in this population of cats were supportive of choledochal cysts (CCs). The maximal diameter of the CBD dilatations exceeded 5 mm in all cases, a sign that has been previously reported to be consistent with EHBDO. In our study, dilatations were segmental rather than diffuse. Given the high morbidity and mortality associated with hepatobiliary surgery in cats, segmental dilatation of the CBD should not prompt emergency surgery. Some cats may respond to medical management. Careful planning for cyst resection was beneficial in one cat. Evaluation of CC morphology (eg, size, location, concurrent intrahepatic anomalies) may assist in selecting cats that could benefit from surgical intervention.

Canine Breed-Specific Hepatopathies

Canine hepatopathies, both congenital and acquired, arise from an interaction between genes and environment. Many show increased breed prevalences. This article reviews the current understanding on breed predispositions for congenital portosystemic shunts; microvascular dysplasia and portal vein hypoplasia; ductal plate abnormalities (congenital hepatic fibrosis and Caroli disease); chronic hepatitis (both copper associated and idiopathic); vacuolar hepatopathies; and gallbladder mucocele. Although all these diseases can occur in many breeds and crossbreeds, understanding breed predispositions helps recognition and will guide future research to improve understanding of causes and treatments.