Bilothorax following cholecystectomy in a dog

Successful resolution of urothorax secondary to non-traumatic uroabdomen in a cat managed with peritoneal dialysis as a bridge to surgery

Case summary

A 9-year-old neutered male domestic shorthair cat was presented for evaluation of severe hemodynamic collapse and suspected lower urinary tract disease. On admission, severe metabolic acidosis, hyperkalemia and azotemia, and electrocardiographic findings consistent with cardiotoxicity were identified. The diagnosis of uroabdomen was made based on abdominal fluid to plasma concentration ratios of creatinine and potassium. A central line catheter was placed percutaneously into the abdomen for peritoneal drainage and used for peritoneal dialysis as a bridge to surgery. Retrograde contrast cystography confirmed rupture of the urinary bladder. Point-of-care ultrasound of the chest postoperatively revealed the presence of mild pleural effusion. Echocardiography was then performed showing no evidence of cardiac disease. Pleural fluid analysis revealed a transudate with a creatinine ratio of 2.38 ([Creatinine]_{pleural fluid}/[Creatinine]_plasma), consistent with the diagnosis of urothorax. The cat recovered uneventfully from surgery and was monitored for signs of respiratory distress during the rest of its stay in hospital. The cat was discharged 4 days later and the pleural effusion resolved without further medical intervention.

Relevance and novel information

There is limited information on the causes of urothorax and uroabdomen management of feline patients. Pleural effusion is a complication observed in critically ill cats secondary to fluid overload, underlying cardiomyopathy, primary thoracic pathology or a combination of these. To our knowledge, this is the first report of urothorax in a cat secondary to non-traumatic uroabdomen. Careful monitoring of respiratory signs consistent with pleural space disease is recommended in cases of uroabdomen.

Bilothorax Associated with Bile Peritonitis in a Dog with No Diaphragmatic Disruption: A Case Report

A 4-year-old intact male mixed-breed dog was presented with vomiting and severe depression of 6-day duration after being struck by a car 2 weeks before presentation. Clinical examination revealed hypothermia, respiratory difficulty, jaundice, and a bicavitary (pleural and peritoneal) effusion. Hematological and biochemical abnormalities included neutrophilic leukocytosis, increased total bilirubin concentration, and increased serum lipase activity. Biochemical and cytological evaluation of both abdominal and thoracic fluids were suggestive of bilious effusions. During celiotomy, a rupture of the cystic duct was observed, which necessitated cholecystectomy. A diaphragmatic rupture was not found. A thoracostomy tube was inserted in the right pleural space, and continuous suction was maintained for 48 hours. The dog was discharged 20 days after surgery and no abnormalities were detected on either blood tests or ultrasonographic examinations of the thorax and abdomen on follow-up examination 7 months after surgery. The presence of a bilothorax should be considered in animals with bile peritonitis, grossly intact diaphragm and pleural effusion. The exact mechanisms of the development of bilothorax are unclear, but the transport of bile through microscopic congenital or acquired weaknesses or defects of the diaphragm, via abdominal lymphatics penetrating the diaphragm and draining into the thoracic lymphatics represent the most probable route.

Canine and Feline Exudative Pleural Diseases

Exudative pleural diseases are a common cause of respiratory distress and systemic illness in dogs and cats. This article covers the pathophysiology, development, and classification of exudative pleural effusions. The most current diagnostic strategies, causes, imaging findings, and medical or surgical treatment options for select diseases are reviewed in detail.

Spontaneous cholecystopleural fistula leading to biliothorax and sepsis in a cat

Case summary

A 13-year-old spayed female domestic shorthair cat presented with pleural effusion and suspected triaditis. Intake vitals and leukocytosis were consistent with a diagnosis of systemic inflammatory response syndrome. Biochemical analysis confirmed a pleural fluid-to-serum bile ratio consistent with a diagnosis of biliothorax. Abdominal ultrasound failed to identify a definitive gall bladder but noted a hypoechoic tubular structure ventral to the liver and contacting the diaphragm. Thoracic ultrasound identified a hyperechoic structure contacting the diaphragm at the same location. Thoracoabdominal CT scan identified a fluid-dense tubular structure extending from ventral to the liver, through a diaphragmatic defect and directly communicating with the pleural space, suspected to be an abnormal gall bladder. The cat was humanely euthanized, and post-mortem analysis confirmed a cholecystopleural fistula arising from the gall bladder with multifocal abscesses, mixed inflammatory hepatic infiltrates and small-cell gastrointestinal lymphoma. Culture of the abscess isolated Parabacteroides merdae, meeting the reported feline criteria for sepsis.

Relevance and novel information

To our knowledge, spontaneous cholecystopleural fistula formation leading to biliothorax and sepsis has not been previously reported in the cat. This case highlights a novel sequela of gall bladder disease in this species, and biliothorax should be a differential diagnosis for pleural effusion in cats with evidence of cholecystitis or triaditis.

Non-iatrogenic traumatic isolated bilothorax in a cat

CASE SUMMARY

A 6-month-old spayed female domestic shorthair cat presented for evaluation of suspected bite wounds over the right caudal thorax and left cranial flank. Thoracic radiographs identified a mild right-sided pneumothorax, a small volume of right-sided pleural effusion, with increased soft tissue opacity in the right cranial and middle lung lobes. Abdominal ultrasound identified a very small gall bladder and several small pockets of free peritoneal fluid. Cytological analysis of peritoneal fluid was consistent with a modified transudate. Following initial diagnostic investigations, yellow-orange fluid began to emanate from the right-sided thoracic wound. Biochemical analysis of this fluid was consistent with bile. Exploratory coeliotomy revealed a right-sided radial diaphragmatic tear, with herniation of the quadrate liver lobe and a portion of the gall bladder into the right pleural space. The gall bladder was bi-lobed and avulsion of a single herniated lobe resulted in leakage of bile into the right pleural cavity, without concurrent bile peritonitis (biloabdomen). The cat underwent total cholecystectomy and diaphragmatic defect repair and recovered uneventfully.

RELEVANCE AND NOVEL INFORMATION

To our knowledge, at the time of writing non-iatrogenic isolated bilothorax without concurrent biloabdomen has not been previously reported in the cat. This case highlights the importance of thorough assessment of cats with seemingly innocuous thoracic bite wounds. Despite the rarity of its occurrence, bilothorax should be considered a differential in cats with pleural effusion, even in the absence of bile peritonitis. We believe that the optimal treatment of cases of bilothorax is multifactorial and should be determined on a case-by-case basis.

Urothorax Associated with Uroperitoneum in a Dog Without Diaphragmatic Disruption

Accumulation of urine in the pleural space secondary to uroperitoneum with no disruption of the diaphragm appears to be a rare pathological condition. A 2 yr old male mixed-breed dog was referred with dyspnea and abdominal pain after a road traffic accident. Plain radiographs demonstrated pleural effusion and reduced serosal detail in the abdominal cavity that was compatible with fluid accumulation. Retrograde urethrography revealed a pelvic urethra rupture. Biochemical analysis of the pleural and abdominal fluid confirmed the diagnosis of urothorax and uroperitoneum. The dog underwent a prepubic urethrostomy and intensive care management. The dog was reported to be in good health after a follow up time of 10 mo. To the authors' knowledge, this is the first reported case of urothorax associated with uroperitoneum with no detectable defects of the diaphragm in a dog.

Biliothorax in a Siamese cat

A 2-year-old male neutered cat presented for further investigation of biliothorax. The cat was initially treated for pyothorax, including bilateral chest drains for lavage of the pleural space. Five days later, the pleural effusion turned clear-yellow and had a bilirubin concentration of 427 μmol/l compared to the serum bilirubin concentration of 15 μmol/l. Exploratory surgery revealed a 2mm tear in the diaphragm, with a corresponding 2mm defect in the diaphragmatic surface of the gall bladder, creating a fistula between the gall bladder and the pleural cavity. The defects were repaired routinely and the cat made a full recovery. It was suspected that the tears had been created at the time of the thoracostomy tube placement. Biliothorax has not been described before in a cat, and appears to be a rare complication following thoracostomy tube placement.