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.     

Pyothorax in a cat managed by intrathoracic debridement and postoperative ventilatory support

: A domestic-longhair cat presented due to lethargy, dyspnoea and hypersalivation. Radiographic examination revealed a bilateral pleural effusion, which was diagnosed as pyothorax based on cytological examination. Ultrasonographic examination revealed extensive loculations within the thoracic cavity. Exploratory sternotomy, under general anaesthesia, allowed the removal of approximately 100 ml of purulent fluid and debridement of a partially walled-off abscess and necrotic material from the pleural cavity. Postoperative positive-pressure ventilation was required due to severe respiratory depression. Intensive postoperative care, including intensive continuous monitoring, thoracostomy tube drainage and lavage of the pleural cavity and oesophagostomy tube feeding, was performed. Complete resolution of clinical signs had occurred by 15 days postoperatively. Clinical or radiographic abnormalities were not detected at a follow-up examination one year after surgery.     

Pyothorax associated with a Mycoplasma sp and Arcanobacterium pyogenes in a kitten

Pyothorax associated with a Mycoplasma sp and Arcanobacterium pyogenes was diagnosed at necropsy in a 1-month-old female Van kitten. The pleural cavity contained approximately 50 mL of blood-tinged, reddish-brown, nonodourous fluid bilaterally. Gram positive coccobacilli were seen in the exudate from necrotic plaques on the pleurae. Mycoplasma sp and A pyogenes were isolated from a sample of the fluid in the pleural cavity. The concomitant presence of Mycoplasma sp and A pyogenes could be considered another variation on the polymicrobial nature of pyothorax and associated pleural lesions in cats.     

Spirocercosis-associated pyothorax in dogs

The records of five dogs diagnosed with spirocercosis-associated pyothorax were retrospectively reviewed. On admission, the most common clinical findings were weakness, anorexia, depression, dyspnoea and fever. All dogs had typical oesophageal Spirocerca lupi granulomas. Contrast thoracic radiography revealed contrast material leakage from the oesophagus into the pleural cavity in two dogs only. All dogs were medically treated with broad-spectrum antibiotics, repeated chest tube drainage and thoracic lavage, and four of the dogs were treated with doramectin. One dog was euthanased due to a concurrent non-related disease at the owners request while the remaining four survived. S. lupi infection should be included in the differential diagnoses of canine pyothorax in endemic areas. Conservative medical management of pyothorax with antihelmintic medication was shown to be effective in the treatment of S. lupi-associated pyothorax.     

Successful medical treatment of 15 dogs with pyothorax

OBJECTIVES: To review the success of non-surgical management, which included antibiotics and a single thoracocentesis, in 15 dogs presenting with pyothorax. METHODS: Sixteen dogs were selected retrospectively from case files at the Veterinary Cardiorespiratory Centre. RESULTS: One dog was diagnosed with a mass suspected to be a pulmonary abscess on ultrasound examination and was referred for surgery. Fifteen dogs were treated medically. Springer spaniels were the most commonly presented breed (six cases) followed by Labrador retrievers (three cases). Under sedation or general anaesthesia, thoracocentesis was performed unilaterally and as much purulent effusion as possible was removed. Lavage of the thorax was not undertaken. In most dogs, antibiotic treatment was ampicillin at a mean dose of 33 mg/kg administered three times daily and 25 mg/kg metronidazole administered twice daily. Antibiotics were provided for a minimum of six weeks. All dogs recovered completely and did not show relapse on prolonged follow-up. This included one dog, which had very widespread pleural adhesions and minimal effusion. CLINICAL SIGNIFICANCE: In dogs that do not have evidence of pulmonary masses or consolidations and no evidence of granular pleural effusion, medical therapy may be curative even in chronic cases of pyothorax with pleural adhesions.     

Pyothorax in nine dogs

The results of treatment of pyothorax using systemic antibiotics, drainage, and lavage of the pleural space, are reported for 9 dogs. All 9 dogs recovered completely. In 8 of the 9 dogs the follow-up period was at least 6 months and in none was there a relapse. The results obtained with this treatment are excellent in comparison with the results that have been reported for treatment with systemic antibiotics and drainage of the pleural space but without lavage. Apart from the addition of pleural lavage to the treatment protocol, the better result might be because migrating plant related foreign bodies did not seem to play an important role in the pathogenesis of pyothorax in this group of dogs.     

Feline pyothorax: a retrospective study of 27 cases in Australia

Pyothorax was diagnosed in 27 cats between 1983 and 2002. In 21 (78%) of the cases, pleural fluid culture and/or cytology was consistent with a mixed anaerobic bacterial infection of oropharyngeal origin. In six cases (22%), infection was caused by unusual pathogens or pathogens of non-oropharyngeal origin, including a Mycoplasma species, Cryptococcus gattii, Escherichia coli, Salmonella typhimurium and Staphylococcus aureus. The overall mortality rate was 22%. Treatment was successful in 18 of 19 cases (95%) where closed thoracostomy tubes were inserted. One case resolved only after thoracotomy. Actinomyces species were isolated in three cases and in contrast to dogs where thoracotomy is recommended, they were resolved with tube thoracostomy. Mechanical complications occurred in 58% of the cats with indwelling chest tubes. Probable mechanisms of pleural space infection were identified in 18 cats (67%) including haematogenous infection (n=1), direct inoculation of bacteria into the pleural space (n=1), intrathoracic oesophageal rupture (n=1) and parapneumonic extension of infection (n=15; 56%). Of the latter, perioperative aspiration was suspected in two cats, parasitic migration in two and antecedent upper respiratory tract infection was implicated in seven. Parapneumonic spread of infection after colonisation and invasion of lung tissue by oropharyngeal flora appears to be the most frequent cause of feline anaerobic polymicrobial pyothorax and contests the widespread belief that direct inoculation of pleural cavity by bite wounds is more common.     

Pyothorax in nine dogs

Summary

The results of treatment of pyothorax using systemic antibiotics, drainage, and lavage of the pleural space, are reported for 9 dogs. All 9 dogs recovered completely. In 8 of the 9 dogs the follow‐up period was at least 6 months and in none was there a relapse. The results obtained with this treatment are excellent in comparison with the results that have been reported for treatment with systemic antibiotics and drainage of the pleural space but without lavage. Apart from the addition of pleural lavage to the treatment protocol, the better result might be because migrating plant related foreign bodies did not seem to play an important role in the pathogenesis of pyothorax in this group of dogs.     

Pleural effusion in cats: 82 cases (1987 to 1995)

Eighty-two cases of feline pleural effusion were identified and reviewed to assess the type of fluid, underlying disease process, predisposing conditions, historical and physical examination findings, laboratory and cytology data, response to treatment and outcome. Pertinent findings included a high occurrence of pleural effusion with mediastinal lymphoma (and other types of intrathoracic neoplasia), pyothorax, cardiomyopathy and feline infectious peritonitis virus infection. Sixteen cases, eight with chylous effusion, had no underlying disease identified. Cats with pyothorax and effusion secondary to trauma had the best prognosis for complete recovery. Otherwise, the outcome was variable and the prognosis was guarded to poor.     

Medical and surgical treatment of pyothorax in dogs: 26 cases (1991-2001)

OBJECTIVE: To compare outcomes of dogs with pyothorax treated medically versus surgically and to identify prognostic indicators for dogs with pyothorax. DESIGN: Retrospective study. ANIMALS: 26 dogs. PROCEDURE: Medical records were reviewed to obtain information regarding signalment, results of physical and laboratory evaluations at the time of initial examination, results of bacterial culture of pleural fluid, radiographic abnormalities, treatment (surgical vs medical), complications, whether the disease recurred, disease-free interval, survival time, and cause of death. RESULTS: Calculated proportions of dogs free from disease 1 year after treatment were 25 and 78%, respectively, for dogs treated medically and surgically. Treatment was 5.4 times as likely to fail in dogs treated medically as in dogs treated surgically. Two regression models relating treatment group (medical vs surgical) to disease-free interval were found to be significant. The first contained terms for medical treatment and isolation of Actinomyces spp from pleural fluid; the second contained terms for medical treatment and radiographic detection of mediastinal or pulmonary lesions at the time of initial examination. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that surgical treatment is associated with a better outcome than medical treatment in dogs with pyothorax. In addition, surgery should be considered if radiographic evidence of mediastinal or pulmonary lesions is detected or if Actinomyces spp is isolated from the pleural fluid.     

Thoracoscopic foreign body removal and right middle lung lobectomy to treat pyothorax in a dog

A three-year-old, 30-kg, spayed female German wirehaired pointer was presented for coughing, pyrexia and lethargy. Thoracic radiographs showed mild right-sided pleural effusion, moderate pneumothorax and a pulmonary lesion in the right middle or caudal lung lobe. A diagnosis of pyothorax was established by fine needle aspiration of the pleural effusion. Thoracoscopic exploration was performed using one-lung ventilation. A vegetal foreign body (grass awn) and an abscess were observed in the distal part of the right middle lung lobe. The foreign body was removed and a right middle lung lobectomy was performed, both thoracoscopically. No complications were noted. The dog was discharged 48 hours after surgery, and no recurrence of the clinical signs was observed during the follow-up time period (three years and three months). Thoracoscopy is a minimally invasive alternative to thoracotomy to explore and successfully treat some non-chronic pyothoraces in dogs, including lesions affecting the right middle lung lobe.     

Evaluation of small-bore wire-guided chest drains for management of pleural space disease

O bjectives : To evaluate the efficacy and practicality of a small-bore wire-guided chest drain for management of pleural space disease in dogs and cats.
M aterials and M ethods : A 14 gauge chest drain was placed using a modified Seldinger technique in animals requiring ongoing management of pleural space disease. A questionnaire was used immediately after placement to collect data regarding the ease of placement, reliability and function of the drain.
R esults : Twenty animals were enrolled in which 29 drains were placed. The most common pleural space disease encountered was pyothorax (10 of 20). Sixteen animals required sedation for placement, and 25 of 29 chest drains were inserted at the first attempt. Most drains were placed in less than 10 minutes. The median length of time of catheter use was three days. Few complications were noted during the insertion and throughout the use of the drains. Clinicians rated drain placement as "easy" in 27 of 29 times and the drain function as "good" in 24 of 29 times.
C linical S ignificance : Small-bore wire-guided chest drains are an effective alternative to larger gauge drains. Only minor complications were seen during insertion of the chest drains, and their performance was deemed satisfactory in most cases.     

Successful treatment of pulmonary aspergillosis in a cat

A 7-year-old, spayed female Domestic Longhair cat was evaluated for a 6-week history of coughing. Thoracic radiography revealed a pleural effusion. Thoracic ultrasound revealed a pleural effusion and a focal lung mass. The cat underwent exploratory thoracotomy and a total left pneumonectomy was performed. Histopathology and cultures revealed fungal pneumonia and pyothorax caused by Aspergillus fumigatus. Abdominal ultrasound, repeat thoracic radiography, urinalysis with culture, and retroviral screening failed to detect evidence of systemic disease. The cat's poorly regulated diabetes mellitus is suspected to be the predisposing factor allowing a fungal pulmonary infection to become established. At 18 months after surgery the cat was still disease-free. To our knowledge this is the first reported case of successful treatment of pulmonary aspergillosis in the cat.     

Canine and feline pyothorax: a retrospective study of 50 cases in the UK and Ireland

Fifty cases (36 dogs and 14 cats) with a confirmed diagnosis of pyothorax were evaluated from five referral institutions in the UK and Ireland. Aetiology, clinical presentation, diagnosis, treatment and outcome of all cases were examined. The underlying cause of pyothorax was determined in 18 per cent of cases. Positive bacteriological cultures of the pleural fluid were obtained in 68.7 per cent of the animals. Treatment modalities included surgery and medical management, involving thoracostomy tube placement, thoracic aspiration, thoracic lavage and antimicrobial therapy. A successful outcome was achieved in 86 per cent of patients.     

Catheter drainage of pleural fluid collections and pneumothorax

A technique for virtually atraumatic placement of small size chest catheters for suction drainage of pleural effusions and pneumothorax in the dog and cat is described. Thirty-nine dogs and two cats were treated for pyothorax (10 cases), hydrothorax (eight). chylothorax (three), haemothorax (three), haemothorax/pneumothorax (three) and pneumothorax (14). In all 41 cases, thin or viscous fluid and/or air were efficiently drained. The mean period of drainage was four days (range, 0.5 to 18 days). The average amount of fluid removed from each patient in 24 hours was 530 ml in pyothorax cases (range, 140 to 1100 ml) and 1300 ml in the other cases (range, 20 to 5000 ml). In 40 cases there were no complications related to the procedure. One dog with severe pleural adhesions was euthanased because of lung perforation and pneumothorax secondary to misplacement of the catheter.     

The pathogenesis of paraesophageal empyema in dogs and constancy of radiographic and computed tomography signs are linked to involvement of the mediastinal serous cavity

The mediastinal serous cavity is a normal anatomic space in the caudal mediastinum. Aims of this anatomic and case series study were to describe the signs of pathologic expansion of the mediastinal serous cavity observed during computed tomography (CT), review the underlying anatomy, perform a literature review, and evaluate the medical records of several dogs with mediastinal serous cavity empyema (paraesophageal empyema). The mesothelial lined mediastinal serous cavity is a cranial extension of the omental bursa, separated from the peritoneal cavity by the diaphragm, in the dorsal part of the caudal mediastinum, to the right of the esophagus, between the heart base and diaphragm. In five adult, large‐breed dogs with surgically and histologically confirmed paraesophageal empyema, macroscopic plant material was found at surgery in two dogs, adherence to adjacent lung was present in three different dogs, accessory lobectomy was performed in two dogs with subacute‐chronic pyogranulomatous pneumonia, and one dog had concurrent pyothorax and mediastinitis, but none had esophageal abnormalities. This study expands our understanding of the pathogenesis and basis for the imaging appearance of paraesophageal empyema in dogs by clarifying the underlying anatomic structures that direct development of this condition. The term empyema accurately describes this condition because the purulent material accumulates within an existing body cavity. The study also provides initial evidence that the development of paraesophageal empyema might be due to local extension of lung disease, such as foreign body migration or pneumonia. Computed tomography was helpful for diagnosis, assessing size, and determining the spread of disease.     

Bacteria associated with pyothorax of dogs and cats: 98 cases (1989-1998)

OBJECTIVE: To determine the organisms most commonly isolated from pleural fluid from dogs and cats with pyothorax. DESIGN: Retrospective study. ANIMALS: 51 dogs and 47 cats. PROCEDURE: Results of bacteriologic culture of pleural fluid samples obtained by means of thoracentesis were obtained from medical records. To obtain information on in vitro antimicrobial susceptibility of organisms commonly isolated from dogs and cats, records of all dogs and cats examined during 1998 were reviewed, and information was obtained on identity and in vitro antimicrobial susceptibility of aerobic organisms isolated from samples other than urine or urinary tract samples. RESULTS: Median ages of dogs and cats were 4 years. Bacteria were isolated from pleural fluid samples from 47 of 51 (92%) dogs and 45 of 47 (96%) cats. Obligate anaerobic bacteria were isolated from 28 dogs and 40 cats. A mixture of obligate anaerobic and facultative bacteria was isolated from 17 dogs and 20 cats. Samples from cats most often yielded a member of the nonenteric group (most commonly members of the genus Pasteurella), whereas those from dogs more often yielded a member of the family Enterobacteriaceae (most commonly E coli). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that antimicrobial agents chosen for the initial treatment of dogs and cats with pyothorax should be active against a mixture of obligate anaerobic and facultative bacteria.     

Atypical presentation of caecal perforation in two horses

This case report describes retroperitoneal and subserosal emphysema as the primary indication of a caecal perforation associated with an episode of colic. Feed contamination was not noted on repeated peritoneal fluid samples or within the peritoneal cavity at the time of surgery; however, subserosal and retroperitoneal emphysema at the base of the caecum was identified during surgical exploration, which later corresponded to retroperitoneal caecal perforation at necropsy examination.     

Pyothorax associated with a Mycoplasma species in a kitten

A 12-week-old kitten with congenital mitral valve dysplasia was shown by ante mortem and post mortem examination to have pneumonia and purulent pleurisy. A Mycoplasma species was isolated from a sample of pleural fluid collected at necropsy. Mycoplasmosis should be considered in the differential diagnosis of pyothorax in cats.     

Canine bicavitary carcinomatosis with transient needle tract metastasis diagnosed by multiplex immunocytochemistry

A 6‐year‐old, male castrated, mixed‐breed dog was referred to the James L. Voss Veterinary Teaching Hospital at Colorado State University for bicavitary effusion. On examination, the dog was tachycardic and tachypneic with bilaterally decreased lung sounds. Thoracic and abdominal ultrasonic examination revealed pleural and peritoneal effusions, which were aspirated and submitted for fluid analysis and cytology. Both cavity fluids were classified as exudates with a large population of vacuolated mononuclear cells. Multiplex immunocytochemistry (ICC) for cytokeratin and vimentin demonstrated exclusively cytokeratin expression, indicating these cells were of epithelial origin. A full diagnostic evaluation was performed, including CBC, clinical chemistry, a pet‐side test for heartworm disease, ehrlichiosis, Lyme disease, and anaplasmosis, imaging modalities of thorax, abdomen, and heart, urinalysis, and fine‐needle aspirations of spleen, liver, and popliteal lymph nodes. The dog was diagnosed with pleural and peritoneal carcinoma with presumed carcinomatosis. A single dose of intracavitary carboplatin was administered before discharge, and over a period of 2 weeks, 5 thoracocenteses were performed. A subcutaneous mass was noted at a thoracocentesis site one week after initial presentation. Cytology of the mass was consistent with carcinoma, and neoplastic seeding of the tumor cells from the thoracocentesis was suspected. The dog was euthanized 15 days after the first visit, and a necropsy was performed. Findings were consistent with carcinomatosis secondary to anaplastic pulmonary carcinoma with transient subcutaneous seeding of neoplastic cells during routine thoracocentesis. This case demonstrates the utility of multiplex ICC in the clinical setting.