Gallbladder Mucocele: Variables Associated with Outcome and the Utility of Ultrasonography to Identify Gallbladder Rupture in 219 Dogs (2007-2016)

Gallbladder mucocele caused by intestinal metaplasia in lithiasic cholecystitis: A case report and literature review of a rare association

INTRODUCTION

Mucin hypersecretion promoted by intestinal metaplasia can lead to gallstone formation. The presence of large amounts of mucin induced by a change in biliary epithelium structure is called a mucocele, a usually benign condition studied among animals but rarely described in humans. This entity must be distinguished from hydrops, a condition secondary to an impacted gallstone in the cystic duct leading to an outlet obstruction and distension of the gallbladder.

PRESENTATION OF CASE

We report a case of a 51-year-old female with lithiasic cholecystitis showing areas of intestinal metaplasia associated with a mucocele. Laparoscopic cholecystectomy was performed with an uneventful postoperative course. Macroscopic findings revealed a dilated gallbladder filled with mucoid fluid. Signs of chronic and focally acute cholecystitis with areas of intestinal metaplasia were observed microscopically.

DISCUSSION

Lithiasic gallbladders can bear a gene that is found in goblet cells of intestinal metaplasia, leading to mucin hypersecretion. Metaplasia - a benign lesion often encountered on cholecystectomy specimens - can be the precursor of carcinoma. Mucin-producing gallbladder carcinoma is a very aggressive tumor that can appear as a mucocele. Consequently, preoperative computed tomography or magnetic resonance cholangiopancreatography should be performed in the presence of an unusual aspect on sonography.

CONCLUSION

Metaplastic changes in gallbladder epithelium associated with an overproduction of mucin and lithiasic cholecystitis reported in this case is a rarity. Malignancy is an alternative diagnosis of gallbladder mucocele that must be suspected whenever preoperative imaging of the gallbladder is atypical.

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

BACKGROUND

Information is limited regarding the prevalence and importance of hepatic histologic abnormalities in dogs with gallbladder mucocele (GBM).

OBJECTIVES

To (a) report prevalence of hepatic histologic abnormalities in dogs with GBM (b) evaluate for association between hepatic abnormalities and outcome in dogs with GBM (c) evaluate whether neutrophil-to-lymphocyte ratio (NLR) differs in dogs with GBM with and without specific hepatic lesions.

ANIMALS

Fifty-two dogs with grossly and histologically confirmed GBM.

METHODS

Multicenter, retrospective study of dogs with GBM undergoing cholecystectomy with concurrent liver biopsy. Archived histological sections of gallbladder and liver evaluated by investigators blinded to data. Proportions of dogs with each histologic abnormality alive vs deceased at 1, 3, and 12 months post-cholecystectomy compared. Mann-Whitney U performed to determine if NLR differed in dogs with or without selected lesions.

RESULTS

51/52 (98%, 95% CI [89%, 99%]) dogs with GBM had at least 1 hepatic histologic abnormality. Hepatic fibrosis (37/51; 73%, 95% CI [59%, 83%]), biliary hyperplasia (29/52; 56%, 95% CI [42%, 68%]), and portal inflammation (25/52; 48%, 95% CI [35%, 61%]) were most common. The proportion of dogs alive vs dead differed based on the fibrosis score at 1, 3, and 12 (P ≤ .04) months post-cholecystectomy. Dogs with hepatic necrosis (P = .006) and cholangitis/cholangiohepatitis (P = .02) had higher NLRs compared to dogs without these lesions.

CONCLUSIONS AND CLINICAL IMPORTANCE

Histologic abnormalities of the liver are common in dogs with GBM. A higher portal fibrosis score might be associated with shortened long-term survival after cholecystectomy for dogs with GBM. An increase in NLR might predict hepatic necrosis and cholangitis/cholangiohepatitis in dogs with GBM.

MUC5AC and MUC5B expression in canine gallbladder mucocele epithelial cells

Gallbladder mucocele (GBM) is one of the most common gallbladder diseases in dogs. Its pathogenesis has not yet been clarified, but excessive accumulation of a secretory gel-forming mucin, MUC5AC in the gallbladder has been reported. This study aimed to ascertain if MUC5AC overproduction resulted in mucus accumulation in the gallbladder during GBM development. Eleven dogs undergoing cholecystectomy who were pathologically diagnosed with GBM were included, and the expression level of mucins, particularly MUC5AC and MUC5B, in their gallbladder epithelial cells was compared with those in normal gallbladder epithelial cells. On reverse transcription-quantitative polymerase chain reaction screening, there was a significant difference (P<0.05) in the mRNA expression level of MUC1, but not of other mucins including MUC5AC and MUC5B, between mucocele and normal gallbladder epithelial cells. Protein expression levels were also evaluated for MUC5AC and MUC5B using immunohistochemistry. There was little immunoreactivity for MUC5AC, whereas MUC5B showed definitive staining in gallbladder epithelial cells. There was no difference in MUC5AC and MUC5B protein expression levels between mucocele and normal gallbladder epithelial cells. These data suggest that excessive production of mucin, especially MUC5AC and MUC5B, does not occur in canine GBM, and that abnormal mucus excretion, rather than excessive mucus production, may be the cause of GBM development.

Clinical Outcomes in Dogs Undergoing Cholecystectomy via a Transverse Incision: A Meta-Analysis of 121 Animals Treated between 2011 and 2021

Although many studies have been conducted on the use of median and transverse incisions in various surgeries in the field of human medicine, related studies in veterinary medicine are lacking. This study aimed to present treatment options for dogs requiring cholecystectomy by reporting the pros and cons of 121 cholecystectomies performed via transverse incision at our hospital over 10 years. In most included cases, nonelective cholecystectomy was performed in an unstable emergency situation. The perioperative mortality rate was 23.14%, which was not significantly different from that of cholecystectomy performed via the conventional midline approach. However, the overall operation time (46.24 ± 6.13 min; range 35-65 min) was shortened by securing an adequate surgical field of view. The transverse incision approach facilitates fast and accurate surgery without increasing the fatality rate in small-breed dogs, in whom securing an adequate surgical field of view is difficult. Thus, transverse incision should be actively considered in dogs undergoing cholecystectomy due to emergency conditions, such as bile leakage or biliary tract obstruction, since prolonged anesthesia can be burdensome. This study may improve cholecystectomy outcomes in small-breed dogs with difficult-to-secure surgical fields.

Unusual Case of Biliary Peritonitis in a Dog Secondary to a Gastric Perforation

Biliary peritonitis is a pathological condition representing a medical emergency with a high risk of mortality. This condition is reported in both human and veterinary medicine following biliary tract rupture, extrahepatic biliary obstructions, gallbladder rupture, trauma, or duodenal perforation. In this report, the first-ever case of biliary peritonitis due to gastric perforation in a Bobtail purebred dog is described, which was probably induced by the administration of nonsteroidal anti-inflammatory drugs (NSAIDs). After an elective splenectomy and castration, the dog was referred to our hospital for medical management for inappetence, mental depression, and multiple episodes of gastric vomits with traces of blood. Clinical diagnostic tests showed the presence of biliary peritonitis. Due to worsening clinical conditions, the patient was subjected to euthanasia. Macroscopic examination showed a free brownish abdominal effusion and the presence of perforating ulcer of the stomach pylorus region.

Gallbladder microbiota in healthy dogs and dogs with mucocele formation

To date studies have not investigated the culture-independent microbiome of bile from dogs, a species where aseptic collection of bile under ultrasound guidance is somewhat routine. Despite frequent collection of bile for culture-based diagnosis of bacterial cholecystitis, it is unknown whether bile from healthy dogs harbors uncultivable bacteria or a core microbiota. The answer to this question is critical to understanding the pathogenesis of biliary infection and as a baseline to exploration of other biliary diseases in dogs where uncultivable bacteria could play a pathogenic role. A pressing example of such a disease would be gallbladder mucocele formation in dogs. This prevalent and deadly condition is characterized by excessive secretion of abnormal mucus by the gallbladder epithelium that can eventually lead to rupture of the gallbladder or obstruction of bile flow. The cause of mucocele formation is unknown as is whether uncultivable, and therefore unrecognized, bacteria play any systematic role in pathogenesis. In this study we applied next-generation 16S rRNA gene sequencing to identify the culture-negative bacterial community of gallbladder bile from healthy dogs and gallbladder mucus from dogs with mucocele formation. Integral to our study was the use of 2 separate DNA isolations on each sample using different extraction methods and sequencing of negative control samples enabling recognition and curation of contaminating sequences. Microbiota findings were validated by simultaneous culture-based identification, cytological examination of bile, and fluorescence in-situ hybridization (FISH) performed on gallbladder mucosa. Using culture-dependent, cytological, FISH, and 16S rRNA sequencing approaches, results of our study do not support existence of a core microbiome in the bile of healthy dogs or gallbladder mucus from dogs with mucocele formation. Our findings further document how contaminating sequences can significantly contribute to the results of sequencing analysis when performed on samples with low bacterial biomass.

Multi-phase MULTIDETECTOR-row computed tomographic features and laboratory findings in dogs with gallbladder rupture

Gallbladder rupture is a life-treating condition in dogs. In human medicine, multidetector-row computed tomography (MDCT) is considered the best modality for the diagnosis of gallbladder rupture. The aims of the study were to describe MDCT features of gallbladder rupture in dogs and to determine the CT findings and laboratory data that differ between dogs with ruptured biliary tree and dogs with biliary disease with no rupture. For this single-center, cross-sectional study were considered for inclusion dogs presented from May 2010 to September 2020, with surgical diagnosis of gallbladder rupture or integrity, who underwent MDCT examination and with CBC and biochemistry results available for review. Forty-seven dogs with different diseases of the biliary tract were included. Seventeen dogs with confirmed gallbladder rupture and 30 dogs with intact gallbladder were included. Multiple MDCT findings showed statistical significance in distinguish dogs with gallbladder rupture: irregular contours of the gallbladder (p < 0.0001), discontinuation of the gallbladder wall (p = 0.0005), adhesions with adjacent organs (p = 0.005), heterogeneous enhancement of the gallbladder wall (p = 0.01), pericholecystic effusion (p = 0.001) and pericholecystic peritonitis (p = 0.001). The presence of three or more of these findings was highly indicative for gallbladder rupture (AUC = 0.921). In this study, MDCT proved to be useful in differentiating dogs with gallbladder rupture from dogs with biliary disease without rupture.

Clinical findings and assessment of factors associated with survival in dogs presenting with hyperbilirubinaemia: 115 cases in Victoria, Australia (2015–2020)

Introduction

Hyperbilirubinaemia is an important clinicopathological finding in canine medicine. The objectives of this study were to describe the clinical presentation and outcome of dogs with hyperbilirubinaemia; also to identify factors associated with survival.

Materials and methods

Retrospective study of dogs with hyperbilirubinaemia from two referral centres in South Australia (2015–2020). Signalment, clinical signs, clinicopathological data, diagnosis and outcome were obtained from searching clinical records. Univariable analysis and logistic regression modelling were used to compare outcomes and overall survival.

Results

A total of 115 cases were included. The most common clinical signs were vomiting (63.5%), anorexia (62.6%), lethargy (55.7%) and pyrexia (18.3%). Pre‐hepatic icterus was diagnosed in 18 cases (15.7%), hepatic icterus in 51 cases (44.3%) and post‐hepatic icterus in 42 cases (36.5%). The median survival time across all cases was 40 days (95% confidence interval [CI]: 9–126 days). There was an increased risk of death in dogs with serum bilirubin greater than 60 μmol/L at diagnosis (odds ratio [OR] = 3.55; 95% CI: 1.53–8.22; p‐value = 0.003) and in dogs with pre‐hepatic icterus compared to hepatic (OR = 4.35; 95% CI: 1.18–16.0; p‐value = 0.027) and post‐hepatic icterus (OR = 6.52; 95% CI: 1.67–25.5; p‐value = 0.007).

Conclusions

Pre‐hepatic icterus was associated with a significantly higher risk of death than hepatic and post‐hepatic icterus. Serum bilirubin >60 μmol/L at diagnosis was associated with a significantly shorter median survival time. This cut‐off may be useful in discussions with owners regarding pursuing further diagnostic investigation and treatment. Further prospective studies are needed to prove the validity of this cut‐off.

Extradural anaesthesia-analgesia in dogs undergoing cholecystectomy: A single centre retrospective study

Objectives

To assess the effects of extradural anaesthesia-analgesia (EAA) in dogs undergoing cholecystectomy.

Materials and methods

Medical records of dogs undergoing cholecystectomy between 2011 and 2019 were retrieved and allocated to two groups depending if analgesia was provided systemically (group SA) or extradurally (EAA). Preoperative data, intraoperative antinociceptive medications, postoperative analgesia, perioperative complications, and food intake were compared.

Results

Overall 41 medical records were included in the study: 19 and 22 dogs were allocated to groups SA and EAA, respectively. In group EAA, an extradural catheter was placed preoperatively in 8 dogs; in the remaining, it was placed postoperatively but an extradural injection was performed preoperatively. The extradural catheter tip was between the 4th lumbar and the 10th thoracic vertebrae. Intraoperatively, nociception was more likely to occur in group SA [OR 55.42 (2.97–1,035.06)]. During the first 24 and 48 h postoperatively, more dogs in group SA required methadone [OR 24 (2.81–268.4) and OR 11.56 (2.37–45.06), respectively] and additional analgesic drugs [OR 25 (3.47–281.9) and OR 35.29 (1.86–668.2), respectively] compared to group EAA. Voluntary postoperative food intake was also significantly higher in group EAA.

Clinical significance

Compared to systemic analgesia, the use of extradural anaesthesia-analgesia reduced perioperative analgesic requirement and promoted postoperative food intake in dogs undergoing cholecystectomy.

High frequency of cholecystitis in dogs with gallbladder mucocoele in Hong Kong

The aims of this retrospective study were to characterise the epidemiological, clinical, histopathological, and microbiological findings as well as surgical outcomes in dogs admitted to a specialist veterinary hospital in Hong Kong for surgical management of gallbladder mucocoele (GBM). Inclusion criteria were cases with histopathological diagnosis of GBM and accompanying abdominal imaging, serum biochemistry, bile culture, and liver biopsy histology results. Fifty-six cases met the inclusion criteria. The median age at diagnosis was 12 years (range, 5-16 years). Miniature or toy pure-breed dogs were most commonly affected, including Poodles, Pomeranians, Schnauzers, Bichon frises and Chihuahuas. However, no breed was over-represented compared with their expected proportions among annual hospital admissions. Histological evidence of cholecystitis was present in 84% of cases, including acute cholecystitis in 18%, chronic cholecystitis in 37.5%, acute on chronic cholecystitis in 28% and acute with necrosis in 6%. The most common liver lesions were cholestasis in 64%, along with portal fibrosis in 55%, oedema in 50% and bile duct hyperplasia in 50%. Bile culture was positive in 29.6% of cases. Escherichia coli and Enterobacter species were most commonly isolated. Stentrophomonas maltophili was cultured from one case. Of the 16 cases where bacteria were isolated from bile culture, 94% had evidence of chronic cholecystitis and 81% had evidence of cholangiohepatitis. Fifty dogs (89.3%) survived to discharge including 5/5 dogs with ruptured gallbladders. Of 34 dogs with follow-up data, 21/34 (61.8%) were still alive 12 months later. Gallbladder mucocoeles were frequently associated with both acute and chronic inflammation. High survival rates to discharge were achieved.

Multidrug resistant Enterococcus faecium isolate from cholangitis/cholecystitis in a dog

Mucocele and cholecystitis were diagnosed in a 10 year-old Shetland-sheepdog presenting aspecific clinical signs. Blood examinations and ultrasonography investigation were performed before to surgical approach, which allowed to collect biopsies and samples for bacteriological analyses. In addition, the patient was subjected to cholecystectomy. A multidrug resistant Enterococcus faecium was isolated from the gallbladder specimens. On the basis of antimicrobial susceptibility test, nitrofurantoin was used. The correct bacteriological diagnosis is necessary to set up effective therapy, influencing the patient's prognosis and improving the recovery time.

Anicteric Gallbladder Rupture with Elevated Bile Acids in Abdominal Effusion in a Dog with Cholecystitis

Anicteric gallbladder rupture has been rarely described in veterinary medicine, and, generally, it has been related to gallbladder wall necrosis secondary to gallbladder mucocele. A 5 yr old, male, neutered Labrador retriever presented for acute onset anorexia, lethargy, and vomiting. Cholecystitis was diagnosed based on the ultrasonographic findings and bactibilia, and, consequently, medical treatment was established. Despite improvement of the patient, a focal ultrasound of the hepatobiliary tract was performed 72 hr after admission for reassessment, revealing gallbladder wall thickening and abdominal effusion. Intracellular bacteria were present in nondegenerated neutrophils, and the effusion was categorized as septic exudate, compatible with septic peritonitis. Exploratory laparotomy confirmed an anicteric gallbladder rupture potentially secondary to cholecystitis and/or previous cholecystocentesis. The patient was not icteric the day of the surgery, serum bilirubin was within normal limits, abdominal fluid bilirubin concentration was below that of serum, and no bile pigment was detected; however, bile acids were significantly higher in the abdominal effusion compared with the serum concentration. This case describes an anicteric gallbladder rupture in a dog with concomitant cholecystitis and raises the question about the sensitivity of bile acid evaluation as a tool for diagnosis of gallbladder rupture and bile peritonitis in dogs.

Prevalence of Empyema or Mucocele or Other Histological Diagnoses in Patients Undergoing Cholecystectomy With Diagnosis of Chronic Cholecystitis

Background

Chronic cholecystitis is inflammation of the gall bladder usually caused by stones. The aim was to find out the prevalence of mucocele and empyema in chronic cholecystitis using cholecystectomy findings and histopathological reports.

Methodology

This was a cross-sectional observational study conducted in Surgical Ward 1, Jinnah Postgraduate Medical Center, Karachi from December 2019 to December 2021 for two years. Patients above 12 years of age diagnosed with chronic cholecystitis with cholelithiasis on clinical examination and investigations were included. Patients who were diagnosed with acute cholecystitis, mucocele, or empyema on clinical examination and ultrasonography were excluded from the study. Laparoscopic cholecystectomy was done and operative findings were noted. Gall bladder specimens were examined for mucocele and empyema and were sent for histopathology. Results were recorded and analyzed.

Results

There were 241 patients diagnosed with chronic cholecystitis with cholelithiasis on clinical examination and investigations. On examination, tenderness in the right hypochondrium was absent in all patients. Chronic cholecystitis was proved on histopathology in 231 patients (95.85%). Other findings diagnosed on peroperative findings and histopathology reports were strawberry gall bladder (2.41%), empyema (0.83%), mucocele (0.41%), and polyp (0.41%). Two hundred eight patients were female (86.31%), 33 were male(13.69%). The male to female ratio was 1:6.43. The average age was 31 years.

Conclusion

Inflammation and fibrosis of the gallbladder around Calot’s triangle increase the chances of vascular and common bile duct injury. In such cases, cholecystectomy can become difficult. It was concluded that empyema, mucocele, and strawberry gall bladder could be found in chronic cholecystitis, and cholecystectomy becomes difficult in such cases.

Ultrasonographic patterns, clinical findings, and prognostic variables in dogs from Asia with gallbladder mucocele

BACKGROUND

Gallbladder mucocele (GBM) is a common biliary disorder in dogs that can be categorized into 6 types, but the value of this classification scheme remains unknown. Cholecystectomy is associated with high death rates and warrants additional interrogation.

OBJECTIVES

Investigate the clinical value of ultrasonographic diagnosis of type of GBM and identify prognostic factors in dogs with GBM undergoing cholecystectomy.

ANIMALS

Two hundred sixteen dogs.

METHODS

Retrospective cohort study. Dogs with GBM diagnosed from 2014 to 2019 at 6 veterinary referral hospitals in Asia. Ultrasonogram images were reviewed and a GBM type (ie, types I-VI) assigned.

RESULTS

Dogs with GBM type V as compared to I (OR, 8.6; 95% CI, 2.6-27.8; P < .001) and III (OR, 10.0; 95% CI, 2.5-40.8; P = .001), and dogs with type VI compared to I (OR, 10.5; 95% CI, 1.8-61.2; P = .009) and III (OR, 12.3; 95% CI, 1.8-83.9; P = .01) were more likely to exhibit signs of biliary tract disease. Independent predictors of death after cholecystectomy included age (OR, 2.81; 95% CI, 1.41-5.59; P = .003) and intraoperative systolic blood pressure (SBP) nadir. There was an interaction between SBP nadir and gallbladder rupture; SBP nadir in dogs with (OR, 0.92; 95% CI, 0.89-0.94; P < .001) and without (OR, 0.88; 95% CI, 0.82-0.93; P < .001) gallbladder rupture.

CONCLUSION AND CLINICAL IMPORTANCE

Increasing developmental stage of GBM could be associated with an increased likelihood of biliary tract related clinical signs. Nadir SBP deserves further investigation as a prognostic or potentially modifiable variable, particularly in the presence of gallbladder rupture.

Factors affecting survival in 516 dogs that underwent cholecystectomy for the treatment of gallbladder mucocele

Gallbladder mucocele (GBM) is a commonly diagnosed disease process in dogs that is associated with high morbidity and mortality if not recognized and appropriately managed. Although the exact mechanism of this disease process is not completely understood, previous studies in smaller populations of dogs have identified multiple factors that predispose to the development of GBM and affect survival. The purpose of this cross-sectional, retrospective study was to evaluate the effects of age, breed category, sex, preoperative antibiotic administration, gallbladder rupture, and a positive biliary culture in dogs that had a cholecystectomy performed for the treatment of GBM. The age (median: 11 years) and percentage of dogs that died within 14 days of cholecystectomy (16.7%) are similar to what have been reported in other studies. Gallbladder rupture and a positive biliary culture occurred in 20.4% and 12.5% of dogs, respectively. Dogs with a gallbladder rupture and positive biliary culture were 2.74 and 3.10 times more likely to die within 14 days of cholecystectomy, respectively. This contradicts a recent study that failed to find a significant association between survival and biliary culture result. Interestingly, younger age was associated with an increased occurrence of gallbladder rupture in that population. Because of the potential effect of gallbladder rupture and a biliary tract infection, abdominal imaging, biliary culture, and empirical preoperative antimicrobial therapy are recommended in dogs undergoing cholecystectomy for the treatment of GBM.

Preoperative serum C-reactive protein concentration can be used to detect gallbladder rupture in dogs with gallbladder mucocele

OBJECTIVE

To determine whether serum C-reactive protein (CRP) concentration could be used to detect gallbladder rupture (GBR) prior to surgery in dogs undergoing cholecystectomy for treatment of gallbladder mucocele (GBM).

ANIMALS

45 dogs that underwent cholecystectomy because of GBM at a companion animal referral hospital from 2017 to 2020.

PROCEDURES

Electronic medical records were reviewed, and dogs were included if serum CRP concentration had been measured within 24 hours prior to cholecystectomy. Dogs were grouped as to whether the gallbladder was found to be ruptured or intact during surgery. Accuracy of using preoperative CRP concentration to predict GBR was compared with accuracy of abdominal ultrasonography and other preoperative blood tests.

RESULTS

GBR was present in 15 dogs at the time of surgery. Median preoperative CRP concentration was significantly higher in dogs with GBR (15.1 mg/dL; interquartile range, 7.4 to 16.8 mg/dL) than in dogs with an intact gallbladder (2.65 mg/dL; interquartile range, 0.97 to 13.4 mg/dL). Sensitivity, specificity, and accuracy of using preoperative CRP concentration to predict GBR were 100%, 67%, and 78%, respectively.

CLINICAL RELEVANCE

Measurement of preoperative CRP concentration provided excellent sensitivity and moderate specificity for detection of GBR in dogs undergoing cholecystectomy because of GBM. Accuracy of using preoperative CRP concentration for detection of GBR was not superior to the accuracy of preoperative abdominal ultrasonography. However, when CRP concentration was combined with results of ultrasonography, the sensitivity, specificity, and accuracy for detection of GBR were 100%, 93%, and 96%, respectively.

Canine extrahepatic biliary disease: what have we learned?

Extrahepatic biliary disease in dogs is commonly encountered in clinical practice worldwide. Diseases in this segment of the biliary tract are diverse and can manifest with mild clinical signs or can be life-threatening. In the last decade there have been advances in diagnostic tests, imaging modalities and therapeutic interventions as well as the identification of novel prognostic variables that could improve outcomes in dogs with extrahepatic biliary disease. Therefore, the objective of this review was to summarise clinically relevant updates of extrahepatic biliary disease in dogs.

Evaluation of coagulation parameters in dogs with gallbladder mucoceles

BACKGROUND

Gallbladder mucocele (GBM) is a common biliary disorder in dogs. Limited information is available on the coagulation status of dogs with GBM.

HYPOTHESIS/OBJECTIVES

To determine patterns of coagulation alterations in dogs with GBM and correlate them with clinicopathologic abnormalities and ultrasonographic findings of disease severity.

ANIMALS

Twenty-three dogs with GBM identified on ultrasound examination were prospectively enrolled.

METHODS

At the time of GBM identification, blood and urine were collected for CBC, serum biochemical panel, urinalysis, prothrombin time, activated partial thromboplastin time (aPTT), factor VIII, protein C (PC), von Willebrand's factor (vWF), antithrombin activity, fibrinogen, D-dimers, and thromboelastrography (TEG). Gallbladder mucoceles were classified into ultrasound types 1 to 5. Medical records were reviewed for clinical presentation, underlying conditions and to determine if systemic inflammatory response syndrome (SIRS) was present.

RESULTS

Based on TEG parameters, maximal amplitude, and G, 19/23 (83%) of dogs with GBM had evaluations consistent with hypercoagulability. On plasma-based coagulation testing, dogs with GBM had increased total PC activity (20/23, 87%), fibrinogen (9/23, 39%), platelet count (9/23, 39%), and D-dimers (6/15, 40%) as well as prolongations in aPTT (9/22, 41%) and low vWF activity (5/21, 24%). No correlation was found between TEG G value and any coagulation or clinical pathology variables, ultrasound stage of GBM or disease severity as assessed by the presence of SIRS.

CONCLUSIONS AND CLINICAL IMPORTANCE

Dogs with ultrasonographically identified GBM have changes in whole blood kaolin-activated TEG supporting a hypercoagulable state although traditional plasma-based coagulation testing suggests that a complex state of hemostasis exists.

Histopathological frequency of canine hepatobiliary disease in the United Kingdom

OBJECTIVES

Canine hepatobiliary disease is common; however, data determining disease frequency and breed predispositions are lacking. The primary objective was to identify the frequency of different hepatobiliary disease in a United Kingdom population of dogs and consequently determine breeds at both an increased and decreased risk of hepatobiliary disease.

MATERIALS AND METHODS

Anonymised histopathology reports from a commercial veterinary diagnostic laboratory, which were submitted between August 2013 and February 2018, were analysed. Data were retrospectively categorised into hepatobiliary diseases according to World Small Animal Veterinary Association Standards and the breed, age and genders recorded. Cases with incomplete data or no definitive diagnosis were excluded. Breed predisposition was calculated using odds ratios and 95% confidence intervals against a United Kingdom-based control population of micro-chipped dogs.

RESULTS

Histopathology results from 4584 cases met inclusion criteria. The most frequent histological diagnoses were reactive hepatitis (n=770); chronic hepatitis (n=735) and reversible hepatocellular injury (n=589). A number of breeds were shown to be at an increased or decreased risk of individual liver diseases.

CLINICAL SIGNIFICANCE

This is the first study to document the histopathological frequency of hepatobiliary diseases in a large cohort of dogs in the United Kingdom, as well as novel possible breed and age predispositions. Despite multivariable analysis not being performed to account for confounding factors, this information hopes to inform and support future investigations for hepatic disease in particular breeds and potential predispositions.

Comprehensive Review of Biliary Peritonitis

Biliary peritonitis is a growing concern in the canine patient and a thorough understanding of the disease will lead to better treatment outcomes. This article reviews the human and veterinary literature pertaining to biliary peritonitis including both scientific reviews and original publications. Compared to human medicine, biliary peritonitis can be difficult to diagnose preoperatively. Multiple risk factors exist increasing the likelihood of development of biliary peritonitis. Treatment recommendations center on stabilization, surgical cholecystectomy, and postoperative supportive care. Clinically, further studies on treatment and prevention in veterinary medicine are warranted.

Clinical characteristics and histology of cholecystectomised dogs with nongravity-dependent biliary sludge: 16 cases (2014-2019)

OBJECTIVES

To report the available histology, biochemistry and clinical progression of dogs without classic overt biliary tract signs that underwent cholecystectomy for nongravity-dependent biliary sludge.

MATERIALS AND METHODS

Case series of client-owned dogs for which a cholecystectomy was performed for nongravity-dependent biliary sludge. In six dogs, for which nongravity-dependent biliary sludge filled less than half of gall bladder volume, gall bladder ejection fractions were measured. Available histology, biochemistry, presenting clinical signs and post-surgical clinical progression were reported.

RESULTS

Sixteen dogs were included in this retrospective case series. No dogs met the histological criteria for gall bladder mucocoeles or had histological evidence of primary hepatitis or cholangitis. Biochemistry was normal for 11 dogs. Hypercholesterolaemia was not noted in any dog. Twelve dogs had cholecystitis (11 lymphoplasmacytic, one neutrophilic) and nine dogs had biliary mucosal hyperplasia. Thirteen dogs had enteritis (12 lymphoplasmacytic, one eosinophilic) and nine dogs had reactive hepatitis (eight lymphoplasmacytic, one neutrophilic). All six dogs with nongravity-dependent biliary sludge that filled less than half of gall bladder volume had sub-optimal gall bladder function. Presenting clinical signs, including diurnal inappetence in the morning and exercise intolerance, resolved in 86% (12/14) of dogs after cholecystectomy and clinical improvement was noted in 81% (13/16) of dogs overall.

CLINICAL SIGNIFICANCE

Duodenal inflammation could potentially impact gall bladder dysmotility in dogs with nongravity-dependent biliary sludge. Furthermore, diurnal inappetence in the morning and exercise intolerance could indicate symptomatic gall bladder disease in dogs with NDBS and can potentially precede more obvious systemic clinical signs associated with gall bladder mucocoeles.

Clinical findings for dogs undergoing elective and nonelective cholecystectomies for gall bladder mucoceles

OBJECTIVES

The purpose of this study was to describe elective and nonelective post-cholecystectomy complications and mortality rates in dogs with a gall bladder mucocele. The secondary purpose was to report complications and mortality rates for different methods of common bile duct catheterisation.

MATERIALS AND METHODS

A multi-institutional retrospective case series was performed to identify dogs with a gall bladder mucocele between 2004 and 2018 that underwent a cholecystectomy. Dogs were classified into nonelective or elective based on the presence or absence, respectively, of gall bladder rupture, biliary duct distension, clinical signs or hyperbilirubinemia. Each cholecystectomy was classified into three groups: duodenotomy and retrograde catheterisation, normograde catheterisation or no catheterisation. Complications were divided into four grades based on increasing severity and mortality rates were assessed for each.

RESULTS

The mortality rate was 2 (6%) out of 31 for dogs undergoing an elective cholecystectomy and 21 (23%) out of 90 for dogs undergoing a nonelective cholecystectomy. The complication rate was 52% for the elective cholecystectomy and 50% for nonelective cholecystectomy. The majority of the complications in the elective category were grade 1 (mild). Post-operative hyperthermia developed in 35% of dogs that had a duodenotomy and retrograde common bile duct catheterisation, in 4% of dogs with a normograde common bile duct catheterisation and in 7% of dogs that did not have the common bile duct catheterised.

CLINICAL SIGNIFICANCE

Elective cholecystectomy in dogs with a gall bladder mucocele in this study carried a low mortality rate and a relatively high frequency of minor complications.

Proteinuria in dogs with gallbladder mucocele formation: A retrospective case control study

Background

Proteinuria is an independent risk factor for morbidity and mortality in dogs. An association between proteinuria and gallbladder mucocele formation in dogs is unknown.

Objective

Determine if gallbladder mucocele formation or clinicopathologic comorbidities are associated with proteinuria.

Animals

Twenty‐five dogs with mucocele formation and 25 breed and age‐matched control dogs from a prior study.

Methods

Retrospective case control study. Proteinuria defined by calculated urine dipstick protein concentration (mg/mL) to urine specific gravity (USG) ratio. Clinicopathologic findings, postcosyntropin cortisol concentration, thyroid function profile, and illness severity score were recorded.

Results

Median urine dipstick protein concentration to USG ratio and number of dogs having a ratio ≥1.5 were significantly higher for dogs with mucocele formation compared to control dogs. Proteinuria was not significantly associated with CBC or serum biochemistry profile abnormalities but increased in relation to severity of illness.

Conclusions and Clinical Importance

Gallbladder mucocele formation is significantly associated with proteinuria in dogs. Diagnosis and treatment of proteinuria in dogs with mucocele formation might minimize long term kidney morbidity in these patients.

Dogs with biliary rupture based on ultrasound findings may have normal total serum bilirubin values

The absence of hyperbilirubinemia can lead to decreased suspicion of biliary rupture in dogs. This delay of suspicion and treatment can result in increased mortality rates. The objective of this retrospective, observational study was to describe ultrasound and serum bilirubin findings in a group of dogs with an ultrasonographic diagnosis of suspected biliary rupture. The records of a single institution were searched over the period of 2007-2019 for cases having ultrasound reports describing suspicion of biliary rupture. Clinical findings for each of the cases were recorded. A total of 35 dogs met inclusion criteria and, of these, 30 dogs had confirmed ruptured biliary tracts. It was found that 40% (12/30) of dogs with confirmed ruptured biliary tracts had a serum bilirubin values within the normal reference range. No statistical difference was found in serum bilirubin values between the ruptured and nonruptured biliary tracts. Leukocytosis and neutrophilia were found to be statistically significant between ruptured and nonruptured biliary tracts. Mucinous material, similar to "white bile" found in human literature, was found within the peritoneal effusion of six dogs with biliary rupture, three of which also lacked bile pigment. Findings from this study indicated that normobilirubinemia may be present in some dogs with biliary rupture, and therefore should not be used as a reason for excluding this differential diagnosis.

Serum 25-hydroxyvitamin D concentrations in dogs with gallbladder mucocele

Gallbladder mucocele (GBM) is a common biliary disorder in dogs. Gallbladder hypokinesia has been proposed to contribute to its formation and progression. The specific cause of gallbladder stasis in dogs with GBM as well as viable treatment options to resolve dysmotility remains unknown. Vitamin D deficiency is one of the many potential causes of gallbladder hypokinesia in humans and repletion results in complete resolution of stasis. Improving our understanding of the relationship between serum vitamin D and GBM could help identify dogs as a model for humans with gallbladder hypokinesia. Furthermore, this relationship could provide insight into the pathogenesis of GBM and support the need for future studies to investigate vitamin D as a novel treatment target. Therefore, goals of this study were i) to determine if serum 25-hydroxyvitamin(OH)D concentrations were decreased in dogs with GBM, ii) if serum 25(OH)D concentrations were different in clinical versus dogs subclinical for GBM, and iii) to determine if serum 25(OH)D concentrations could predict the ultrasonographic type of GBM. Sixty-two dogs (clinical, n = 26; subclinical, n = 36) with GBM and 20 healthy control dogs were included in this prospective observational study. Serum 25(OH)D concentrations were measured with a competitive chemiluminescence immunoassay. Overall, dogs with GBM had lower serum 25(OH)D concentrations than control dogs (P = 0.004). Subsequent subgroup analysis indicated that this difference was only significant in the subclinical group compared to the control dogs (P = 0.008), and serum 25(OH)D concentrations did not significantly differ between dogs clinical for GBM versus subclinical or control dogs, indicating that inflammatory state in clinical dogs was not the major constituent of the observed findings. Decreasing serum 25(OH)D concentrations, but not clinical status, was associated with a more advanced developmental stage of GBM type determined by ultrasonography. Our results indicate that vitamin D has a role in dogs with GBM. Additional studies are needed to assess if reduced vitamin D in dogs with GBM is a cause or effect of their biliary disease and to investigate if vitamin D supplementation could be beneficial for dogs with GBM.

Impact of intra-operative hypotension on mortality rates and post-operative complications in dogs undergoing cholecystectomy

OBJECTIVES

To report the mortality rate within a cohort of dogs undergoing cholecystectomy and investigate the impact of intra-operative hypotension on mortality.

MATERIALS AND METHODS

Clinical records at five UK referral centres were reviewed for dogs undergoing cholecystectomy. Data collected included presenting signs, pre-operative blood test results, intra-operative data including frequency and duration of hypotension and the incidence and type of post-operative complications.

RESULTS

Data from 119 dogs were included. Sixteen dogs (13%) died before discharge and by 28 days after surgery the total mortality was 19 dogs (17%). Hypotension lasting over 10 minutes during general anaesthesia occurred in 65 dogs (54.6%), with a mean ± sd duration of 36.1 ± 30.0 minutes. Intra-operative hypotension or the number of hypotensive episodes did not appear to be associated with in-hospital or 28-day mortality. American Society of Anaesthesiologists grade (of fitness for surgery) was significantly associated with both in-hospital and 28-day mortality on univariable analysis, as were post-operative hypoproteinaemia, ileus and pancreatitis. However on multivariable analysis, only ileus and pancreatitis were found to significantly impact mortality.

CLINICAL SIGNIFICANCE

Dogs presenting with a higher American Society of Anaesthesiologists grade appear to have a higher risk of mortality, although intra-operative hypotension did not appear to be part of this risk.

Prevalence and impact of cholecystitis on outcome in dogs with gallbladder mucocele

BACKGROUND

Gallbladder mucocele is a potentially life-threatening extrahepatic biliary disease in dogs. The primary aims of this study were to evaluate the prevalence of cholecystitis in dogs with gross and histopathologically confirmed gallbladder mucocele and to investigate if there is an association between cholecystitis, including its subtypes (eg, acute, acute on chronic, with necrosis, chronic), and survival. Our secondary objective was to evaluate if there is an association between cholecystitis and intraoperative bacteriological culture positivity.

KEY FINDINGS

Two hundred nineteen dogs with gallbladder mucocele were included in this multi-institutional retrospective study, of which 63 (28.8%) dogs had histopathological evidence of cholecystitis. The most common forms of cholecystitis were acute on chronic (n = 22/63, 34.9%) and with necrosis (n = 20, 31.7%). Thirty-one (14.1%) dogs had growth of at least 1 bacterial isolate; however, 88.7% had antimicrobials administered within the 48 hours before surgery or intraoperatively. There was not an association between cholecystitis or its subtypes and survival. Furthermore, there was not an association between cholecystitis and intraoperative bacteriological culture positivity. A total of 38 (17.4%) dogs either died or were euthanized during hospitalization.

SIGNIFICANCE

Cholecystitis is a common comorbidity in dogs with gallbladder mucocele but was not associated with decreased survival.

CT attenuation values and mineral distribution can be used to differentiate dogs with and without gallbladder mucoceles

Gallbladder mucoceles are potentially fatal in dogs. Multiphase CT angiography was performed to evaluate the canine gallbladder in three conditions: no sludge, sludge occupying ≥25% of the lumen, and mucoceles. Twenty dogs with normal hepatobiliary bloodwork and no-to-minimal gallbladder sludge, 13 dogs with normal bloodwork and ≥25% sludge in the gallbladder lumen, and 18 dogs with histologically confirmed gallbladder mucoceles were enrolled in a prospective, observational diagnostic accuracy study. Three regions of interest (ROI) were stratified in the dorsal-ventral orientation and a single ROI was measured within the hepatic parenchyma. Mean attenuation and presence of mineral were recorded. Average Hounsfield units (HU) were recorded for precontrast, arterial, portovenous, and late venous phases. The overall median HU value for mucoceles was significantly higher than gallbladders without sludge and with sludge; precontrast median overall attenuation was 49.3, 35.8, and 39.7 HU, respectively (P < .000004). Mineral was seen in four (20%) dogs with no sludge, seven (56%) dogs with sludge, and nine (50%) dogs with mucoceles. Mineral in the dogs with mucoceles was located within the central aspect of the gallbladder lumen in 67% of mucoceles; this mineral distribution was not seen in any dog without a mucocele. Computed tomography can differentiate a subset of gallbladder mucoceles from dogs with and without gallbladder sludge, especially in the precontrast series. An HU value of 48.6 is 52% sensitive and 96% specific for a gallbladder mucocele. A hyperattenuating gallbladder on precontrast CT images and centrally distributed mineral can be a gallbladder mucocele.

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

BACKGROUND

Gallbladder mucoceles (GBM) typically are treated by cholecystectomy. Medical management rarely has been reported and medical and surgical management have not been compared.

HYPOTHESIS/OBJECTIVES

To compare survival of dogs treated for GBM by medical management or cholecystectomy or both.

ANIMALS

Eighty-nine client-owned dogs diagnosed with GBM that received cholecystectomy or medical treatment or both from 2011 to 2017.

METHODS

Potential cases were identified by searching the medical records database. Data collected included signalment, clinicopathologic results, treatments, and ultrasonographic images and reports. Dogs were grouped according to the treatment received (medical management, surgical treatment, or both) that was chosen at the discretion of the attending veterinarian. Survival analysis was performed and prognostic variables identified and compared between treatment groups.

RESULTS

Of dogs surviving at least 14 days after diagnosis, median survival times were 1802 (95% confidence interval [CI], 855-not reached) days, 1340 (95% CI, 444-1340) days, and 203 (95% CI, 18-525) days, for the surgical, medical, and medical then surgical treatment groups, respectively, and differed significantly (P < .0001). Gallbladder mucocele type (P = .05), serum alkaline phosphatase activity (P = .0001), and serum creatinine (P = .002) and phosphorus (P = .04) concentrations were associated with decreased survival across groups. Suspicion of biliary rupture on abdominal ultrasound (AUS) examination was correlated with increased survival in the surgical group (P = .02).

CONCLUSIONS AND CLINICAL IMPORTANCE

Cholecystectomy for the treatment of GBM results in the best long-term survival in dogs surviving the immediate postoperative period (14 days) compared to medical management. Although medical management is associated with shorter survival compared to surgical treatment, it is a reasonable alternative when surgery cannot be pursued.

Effect of clinical signs, endocrinopathies, timing of surgery, hyperlipidemia, and hyperbilirubinemia on outcome in dogs with gallbladder mucocele

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.

Investigation of adrenal and thyroid gland dysfunction in dogs with ultrasonographic diagnosis of gallbladder mucocele formation

Gallbladder mucocele formation is an emerging disease in dogs characterized by increased secretion of condensed granules of gel-forming mucin by the gallbladder epithelium and formation of an abnormally thick mucus that can culminate in obstruction of the bile duct or rupture of the gallbladder. The disease is associated with a high morbidity and mortality and its pathogenesis is unknown. Affected dogs have a significantly increased likelihood of concurrent diagnosis of hyperadrenocorticism, hypothyroidism, and hyperlipidemia. Whether these endocrinopathies represent coincidental primary disease processes that exacerbate gallbladder mucocele formation in predisposed dogs or reflect a concurrent disruption of endocrine and lipid metabolism is unclear. In this study, we investigated a hypothesis that dogs with gallbladder mucocele formation would have a high prevalence of occult and atypical abnormalities in adrenal cortical and thyroid gland function that would suggest the presence of endocrine disruption and provide deeper insight into disease pathogenesis. We performed a case-control study of dogs with and without ultrasonographic diagnosis of gallbladder mucocele formation and profiled adrenal cortical function using a quantitative mass spectrometry-based assay of serum adrenal-origin steroids before and after administration of synthetic cosyntropin. We simultaneously profiled serum thyroid hormone concentrations and evaluated iodine sufficiency by measurement of urine iodine:creatinine ratios (UICR). The studies were complemented by histological examination of archival thyroid tissue and measurements of thyroid gland organic iodine from dogs with gallbladder mucocele formation and control dogs. Dogs with gallbladder mucocele formation demonstrated an exaggerated cortisol response to adrenal stimulation with cosyntropin. A prevalence of 10% of dogs with gallbladder mucocele formation met laboratory-based criteria for suspect or definitive diagnosis of hyperadrenocorticism. A significantly greater number of dogs with gallbladder mucocele formation had basal serum dehydroepiandrosterone (DHEAS) increases compared to control dogs. A high percentage of dogs with gallbladder mucocele formation (26%) met laboratory-based criteria for diagnosis of hypothyroidism, but lacked detection of anti-thyroglobulin antibodies. Dogs with gallbladder mucocele formation had significantly higher UICRs than control dogs. Examination of thyroid tissue from an unrelated group of dogs with gallbladder mucocele formation did not demonstrate histological evidence of thyroiditis or significant differences in content of organic iodine. These findings suggest that dogs with gallbladder mucocele formation have a greater capacity for cortisol synthesis and pinpoint DHEAS elevations as a potential clue to the underlying pathogenesis of the disease. A high prevalence of thyroid dysfunction with absent evidence for autoimmune thyroiditis suggest a disrupted thyroid hormone metabolism in dogs with gallbladder mucocele formation although an influence of non-thyroidal illness cannot be excluded. High UICR in dogs with gallbladder mucocele formation is of undetermined significance, but of interest for further study.

Gall bladder mucoceles in Border terriers

Background

Gall bladder mucoceles (GBM) are a leading cause of biliary disease in dogs with several breeds, including the Shetland Sheepdog, American Cocker Spaniel, Chihuahua, Pomeranian, and Miniature Schnauzer apparently predisposed.

Objective

To determine risk factors, clinical features, and response to treatment of GBM in Border terriers (BT).

Animals

Medical records of 99 dogs (including 51 BT) with an ultrasonographic (±histopathologic) diagnosis of GBM from three referral centers in the United Kingdom were collected. A control group of 87 similar‐aged BT with no ultrasonographic evidence of gall bladder disease was selected for comparison.

Method

Retrospective case‐control study. Odds ratios were calculated to establish breed predisposition. Signalment, presence of endocrine disease, clinicopathologic results, and outcome were compared between the BT, other breeds, and control BTs.

Results

The odds of identifying a GBM in a BT in this hospital population was 85 times that of all other breeds (95% confidence interval 56.9‐126.8). BT had similar clinical signs and clinicopathologic changes to other breeds with GBM. There was no evidence that endocrinopathies were associated with GBM in BT.

Clinical Significance

A robust breed predisposition to GBM is established for the BT.