Respiratory distress in MWDs generally develops from the following anatomically based diseases and conditions:

• Upper airway obstructions (nasal cavity, oropharynx, larynx, and extra-thoracic trachea)
• Lower airway obstructions (intra-thoracic trachea and bronchi)
• Pulmonary parenchymal disease (bronchioles, alveoli, and interstitial space)
• Restrictive airway compromise (pleural space disease)

MWDs often display characteristic breathing patterns that help localize the problem to the primary anatomical area involved.

A clinical algorithm for differentiating the cause and location of an MWD’s respiratory distress is Figure 1.