Successful medical treatment of 15 dogs with pyothorax

CT findings, management and short-term outcome of dogs with pyothorax: 101 cases (2010 to 2019)

OBJECTIVES

To describe diagnosis, CT findings, management and short-term outcome of a large population of canine pyothorax cases.

METHODS

Retrospective analysis of 101 canine pyothorax cases at two UK referral centres. Medical records and CT images were reviewed. Dogs were included if pre- and post-contrast CT was performed within 48 hours of presentation.

RESULTS

CT abnormalities included pleural thickening (84.1%), pannus (67.3%), pneumothorax (61.4%), mediastinal effusion (28.7%), pulmonary (13.8%) and mediastinal (7.9%) abscessation, foreign body presence (7.9%), foreign body tracts (6.9%) and pneumonia (6.9%). Seventy-one percent of dogs were managed surgically, of which 90.2% survived, and 29% were managed medically, of which 72.4% survived. Overall mortality was 14.8% and 86.6% of these dogs died within 48 hours of admission. All dogs with evidence of a foreign body on CT underwent surgery.

CLINICAL SIGNIFICANCE

Mortality in our population was low and most dogs that died did so within 48 hours of hospitalisation, regardless of management type.

Short- and long-term outcome in cats diagnosed with pyothorax: 47 cases (2009-2018)

OBJECTIVES

The aims of this retrospective study were to report the short- and long-term outcome in cats treated for pyothorax and to identify prognostic indicators as well as determine recurrence rate.

METHODS

Medical records from April 2009 to August 2018 were retrospectively reviewed. Cases were included if a diagnosis of pyothorax was confirmed via cytology and/or culture of pleural fluid. Cats diagnosed with or suspected of having other thoracic diseases and cats with no evidence of pleural effusion were excluded from the study.

RESULTS

Fifty-five cats met the inclusion criteria. Eighty five percent (n=47) cats underwent medical management with thoracostomy tubes, pleural lavage and broad-spectrum antibiotics. Fifteen percent (n=5) cases failed medical treatment and underwent thoracotomy. Twenty eight percent (n=13) did not survive to hospital discharge. Short-term survival (14 days) was achieved in 72% (n=34). Long-term follow-up was available for 31 of 34 with a long-term survival rate of 68% (n=30). The recurrence rate was 6% (n=2).

CONCLUSION

For cats with pyothorax that survive to discharge the prognosis is excellent and the condition is associated with a low recurrence rate.

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.

Utility of bronchoscopy combined with surgery in the treatment and outcomes of dogs with intrathoracic disease secondary to plant awn migration

OBJECTIVE

To evaluate the diagnostic and therapeutic utility of bronchoscopy in dogs undergoing computed tomography (CT) and surgery for intrathoracic disease (pyothorax and pneumothorax) secondary to migrating plant awns (MPA) and to report outcomes in dogs that did and did not undergo bronchoscopy in addition to CT and surgery.

STUDY DESIGN

Retrospective case series.

ANIMALS

Thirty-seven client-owned dogs.

METHODS

Medical records from 2008 to 2017 were reviewed for dogs with documented MPA in the thoracic cavity treated with CT and surgery with or without bronchoscopy. Information regarding diagnostics, treatments, complications, and outcomes relating to hospitalization was evaluated.

RESULTS

At least one abnormal lung lobe was identified by CT in all dogs. Bronchial abnormalities were identified with bronchoscopy in 21 of 22 dogs (95.4%) with available reports. Agreement between CT and bronchoscopy findings ranged from 50% to 81.8%, depending on lung lobe. Thirty-six dogs had one or more lung lobes surgically removed. Thirty-seven MPA were retrieved via bronchoscopy in 10 of 27 (37%) dogs, and 39 MPA were retrieved at surgery in 26 of 37 (70.3%) dogs. Actinomyces spp. were cultured from surgical samples in 7 of 33 (21.2%) dogs. Thirty-five of 37 (94.6%) dogs survived to discharge.

CONCLUSION

Migrating plant awns were successfully retrieved via bronchoscopy. Agreement between CT findings and bronchoscopy was inconsistent, so there may be roles for both modalities. Short- and long-term survival was excellent in this cohort.

CLINICAL SIGNIFICANCE

Bronchoscopy may allow for diagnostic and therapeutic advantages compared with CT in dogs with endobronchial MPA. Actinomyces spp appear to be variably present in surgically acquired bacterial cultures in dogs with MPA.

Video-assisted thoracic surgery for the management of pyothorax in dogs: 14 cases

OBJECTIVE

To report the perioperative findings and outcome of dogs undergoing video-assisted thoracic surgery (VATS) for the management of pyothorax.

DESIGN

Multi-institutional, retrospective study.

ANIMALS

Client-owned dogs (n = 14).

METHODS

Medical records of dogs with pyothorax managed via VATS were reviewed for signalment, history, clinical signs, clinicopathological findings, diagnostic imaging results, surgical variables, bacterial culture and sensitivity results, post-operative management and outcome. VATS was performed after placing a paraxyphoid endoscopic portal and 2-3 intercostal instrument portals. VATS exploration was followed by one or more of the following: mediastinal debridement, tissue sampling, pleural lavage, and placement of a thoracostomy tube.

RESULTS

Two dogs (14%) required conversion from VATS to an open thoracotomy to completely resect proliferative mediastinal tissue. These dogs had severe pleural effusion on preoperative thoracic radiographs and one had severely thickened contrast-enhancing mediastinum on preoperative computed tomography (CT). The cause of pyothorax was identified as a penetrating gastric foreign body (n = 2), migrating plant material (n = 2), and idiopathic (n = 10). The median follow-up time was 143 days (range, 14-2402 days). All dogs were discharged from the hospital and their clinical signs resolved. One patient had recurrence of a pyothorax requiring revision surgery 17 months postoperatively.

CONCLUSION

VATS allows minimally invasive treatment of uncomplicated canine pyothorax. Preoperative thoracic CT may help identify candidates for VATS among dogs with pyothorax.

Antimicrobial use Guidelines for Treatment of Respiratory Tract Disease in Dogs and Cats: Antimicrobial Guidelines Working Group of the International Society for Companion Animal Infectious Diseases

Respiratory tract disease can be associated with primary or secondary bacterial infections in dogs and cats and is a common reason for use and potential misuse, improper use, and overuse of antimicrobials. There is a lack of comprehensive treatment guidelines such as those that are available for human medicine. Accordingly, the International Society for Companion Animal Infectious Diseases convened a Working Group of clinical microbiologists, pharmacologists, and internists to share experiences, examine scientific data, review clinical trials, and develop these guidelines to assist veterinarians in making antimicrobial treatment choices for use in the management of bacterial respiratory diseases in dogs and cats.

A clinical review of the pathophysiology, diagnosis, and treatment of pyothorax in dogs and cats

OBJECTIVE

To review the current literature in reference to the pathophysiology, diagnosis, and treatment of pyothorax in dogs and cats.

ETIOLOGY

Pyothorax, also known as thoracic empyema, is characterized by the accumulation of septic purulent fluid within the pleural space. While the actual route of pleural infection often remains unknown, the oral cavity and upper respiratory tract appear to be the most common source of microorganisms causing pyothorax in dogs and cats. In human medicine, pyothorax is a common clinical entity associated with bacterial pneumonia and progressive parapneumonic effusion.

DIAGNOSIS

Thoracic imaging can be used to support a diagnosis of pleural effusion, but cytologic examination or bacterial culture of pleural fluid are necessary for a definitive diagnosis of pyothorax.

THERAPY

The approach to treatment for pyothorax varies greatly in both human and veterinary medicine and remains controversial. Treatment of pyothorax has classically been divided into medical or surgical therapy and may include administration of antimicrobials, intermittent or continuous thoracic drainage, thoracic lavage, intrapleural fibrinolytic therapy, video-assisted thoracic surgery, and traditional thoracostomy. Despite all of the available options, the optimal treatment to ensure successful short- and long-term outcome, including the avoidance of recurrence, remains unknown.

PROGNOSIS

The prognosis for canine and feline pyothorax is variable but can be good with appropriate treatment. A review of the current veterinary literature revealed an overall reported survival rate of 83% in dogs and 62% in cats. As the clinical presentation of pyothorax in small animals is often delayed and nonspecific, rapid diagnosis and treatment are required to ensure successful outcome.

Prevalence, outcome and risk factors for postoperative pyothorax in 232 dogs undergoing thoracic surgery

Objective

To determine the prevalence, outcome and risk factors for postoperative pyothorax in dogs undergoing thoracic surgery.

Methods

Case records were reviewed retrospectively to identify dogs with post thoracic surgery pyothorax, defined as septic neutrophilic inflammation within the pleural space based on cytology and/or a positive bacterial culture of pleural fluid. Those identified were reviewed for potential risk factors for postoperative pyothorax based on biological plausibility and previously published data. These potential risk factors were explored by multivariable logistic regression.

Results

Of 232 dogs undergoing thoracic surgery, 15 (6·5%) dogs developed pyothorax. Bacteria cultured included methicillin-resistant Staphylococcus aureus and multi-resistant Escherichia coli. Of these dogs, six died, four were euthanased and five were treated successfully. A diagnosis of idiopathic chylothorax [Odds Ratio (OR)=12·5, 95% Confidence Interval (CI)=2·7-58·5, P=0·001], preoperative intrathoracic biopsy (OR=14·3, 95% CI=1·7-118·7, P=0·014) and preoperative thoracocentesis (OR=11·2, 95% CI=1·6-78·2, P=0·015) were identified as independent risk factors for development of postoperative pyothorax.

Clinical Significance

Idiopathic chylothorax, intrathoracic biopsy and prior thoracocentesis are independent risk factors for postoperative pyothorax, which was associated with a 67% mortality rate.

Intra-thoracic pyogranulomatous disease in four working dogs

CASE HISTORY

Four working dogs were presented to veterinary clinics in New Zealand for weight loss or swelling of the thoracic wall. All dogs were large-breed males between the ages of 4 and 7 years, and actively involved in farm work. The two dogs with swelling of the thoracic wall had recent histories of work-related trauma.

CLINICAL FINDINGS AND DIAGNOSIS

All four dogs were diagnosed with intra-thoracic pyogranulomatous disease via diagnostic imaging and surgical exploration. Two dogs had confirmed infection with Actinomyces viscosus, while a third had suspected Actinomyces or Nocardia spp. infection. The fourth dog had a streptococcal infection, and a grass-seed foreign body was removed at surgery. Two dogs successfully returned to work, however euthanasia was requested by the owners of the other two, either during surgery, due to intra-thoracic haemorrhage, or shortly after, with post-operative meningitis.

CLINICAL RELEVANCE

Due to the high value of working dogs in New Zealand, and the higher-than-average risk profile for intra-thoracic pyogranulomatous disease, veterinarians should be aware of this syndrome, and should seek to appropriately diagnose and aggressively treat it surgically.

Feline pyothorax - new insights into an old problem: part 2. Treatment recommendations and prophylaxis

Until recently, pyothorax in the cat has been generally considered to have a poor prognosis. However, it has become clear that most cats that survive the first 48 h following presentation can be successfully treated with aggressive medical management. In this second part of a two-part review, logical guidelines for the management of the disease are discussed, with particular emphasis on antimicrobial selection. Patient stabilisation and supportive care, techniques for pleural space drainage and lavage and indications for surgery are reviewed.

Medical and surgical management of pyothorax

Pyothorax is the accumulation of septic suppurative inflammation within the pleural cavity. The cause and source of infection in dogs and cats often are unknown. Management of these cases can be challenging, because controversy exists over the best method for treatment. Reported outcomes and recurrence rates vary widely.