Pyothorax in Neonatal Boxer

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.

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.

A review of the pathophysiology, classification, and analysis of canine and feline cavitary effusions

Effusion is the abnormal accumulation of fluid within a body cavity that can result from a variety of disease processes. This article reviews the normal production and resorption of body cavity fluid and the pathophysiology of abnormal fluid accumulation. In addition, classification schemes, differential diagnoses, and currently available diagnostic tests for evaluation of effusions are reviewed.

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.

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.