Canis ISSN: 2398-2942

Lung: pulmonary emphysema

Contributor(s): Serena Brownlie, Lynelle Johnson

Introduction

  • Uncommon, usually incidental finding at post-mortem examination, rarely of clinical significance.
  • Cause: chronic respiratory diseases, eg chronic bronchitis, rarely congenital.
  • Signs: expiratory respiratory difficulty, inspiratory crackles on auscultation, wheezing, cyanosis.
  • Diagnosis: radiography.
  • Treatment: treat underlying disease, lobectomy if congenital and less than 3 lobes affected.
  • Prognosis: rarely causes clinical problems, congenital form may result in death from pneumothorax.

Pathogenesis

Etiology

  • Congenital.
  • Chronic respiratory diseases.

Specific

  • Respiratory distress (all causes).
  • Damage to alveoli walls.

Pathophysiology

  • Increased negative intrapleural pressure associated with partial respiratory tract obstruction → tearing of bronchoalveolar walls.
  • Emphysema is caused by the coalescence of the alveoli into large cavernous spaces.
  • During inspiration there is overinflation of the emphysematous lung areas with consequent air trapping during expiration resulting in expiratory difficulty.
  • Large cavities (bullae) can be identified radiographically.
  • In acquired emphysema these changes are secondary to chronic respiratory diseases such as chronic bronchitis Chronic bronchitis or bronchopneumonia (the latter 2 conditions may also be the consequence of emphysema).
  • Congenital lobar and bullous forms are described in young dogs, but are rare conditions.

Timecourse

  • Months to years.
  • Pneumothorax Pneumothorax may develop within minutes once bullae rupture.

Diagnosis

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Treatment

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Outcomes

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Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Au J J, Weisman D L, Stefanacci J D, Palmisano M P (2006) Use of computed tomography for evaluation of lung lesions associated with spontaneous pneumothorax in dogs: 12 cases (1999-2002). JAVMA 228 (5), 733-737 PubMed.
  • Puerto D A, Brockman D J, Lindquist C, Drobatz K (2002) Surgical and nonsurgical management of selected risk factors for spontaneous pneumothorax in dogs: 64 cases (1986-1999). JAVMA 220 (11), 1670-1674 PubMed.
  • Valentine A, Sneak D, Allen D, Mauterer J & Minihan A (1998) Spontaeous pneumothorax in dogs. Comp Cont Ed Pract Vet 18 (1), 53-62 VetMedResource.


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