Introduction

• Abscessation of the respiratory tract is rare.
• Cause: foreign body, complication of other respiratory pathology.
• Signs: depends on location to some extent:
  • Pyrexia.
  • Cough.
  • Dyspnea.
• Diagnosis: radiography, bronchoscopy.
• Treatment: antibiotics, surgery.
• Prognosis: guarded.

Pathogenesis

Etiology

• Often associated with underlying pathology:
  • Direct trauma, eg bite wound.
  • Focal pneumonia.
  • Necrotic tumor.
  • Foreign body, eg migrating grass seed.
  • Parasitic infection.
  • Other primary pulmonary conditions.

Predisposing factors

General

• Immunosuppression, eg FIV Feline immunodeficiency virus disease or general debilitation.

Pathophysiology

• Abscessation may occur in:
  • Upper respiratory tract: larynx, trachea.
  • Lower respiratory tract: bronchi.
  • Pulmonary parenchyma.
  • Mediastinum.

• Focal damage and/or reduced local immunity   →   infection.
• Infection may spread locally, along airways or via hematogenous route.
• Clinical signs result from:
  • Loss of functional pulmonary parenchyma.
  • Airway obstruction.
  • Loss of functional pulmonary capacity, eg pyothorax Pyothorax.
  • Systemic spread of infection.

Timecourse

• Weeks to months.

Diagnosis

Treatment

Outcomes