Introduction

• Abscessation of the respiratory tract is rare in dogs.
• Cause: foreign body, complication of other respiratory pathology.
• Signs: depends on location to some extent; may include pyrexia, cough, dyspnea.
• Diagnosis: radiography, bronchoscopy, ultrasonography.
• Treatment: antibiotics, surgery.
• Prognosis: guarded.

Pathogenesis

Etiology

• Often associated with underlying pathology:
  • Foreign body Airway foreign body , eg migrating grass awn.
  • Focal pneumonia Lung: bacterial pneumonia.
  • Necrotic tumor Lung: pulmonary neoplasia.
  • Parasitic infection, eg filaroides Oslerus osleri infection /dirofilariasis Canine cardiopulmonary dirofilariasis
  • Direct trauma, eg stick injury or bite wound
  • Other primary pulmonary conditions, eg chronic bronchitis Chronic bronchitis

Predisposing factors

• Immunosuppression or general debilitation.

Pathophysiology

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

• 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.
• Hypertrophic pulmonary osteopathy (HPOA) Hypertrophic osteopathy may develop.

Timecourse

• Weeks to months.

Diagnosis

Treatment

Outcomes