5-Year-Old FS Dachshund

Signalment & History

A 5 year old FS Dachshund presents  for coughing for several days.

On presentation, she had mild crackles in the right thorax, a heart rate of 120bpm, respiratory rate of 55brpm, and a rectal temperature of 102.7F.

Findings

The esophagus is moderately, diffusely gas distended in all views, causing ventral displacement of the trachea (creating a tracheal stripe sign). The luminal diameter of the intra-thoracic esophagus is indicated by the pink lines.

There is a focal and lobar alveolar pulmonary pattern with multiple air bronchograms in the right middle lung lobe.

A lobar sign is seen in the ventral aspect of the right middle lung lobe, causing border effacement of the caudal right aspects of the cardiac silhouette.

Diagnosis

This patient was diagnosed with megaesophagus and secondary aspiration pneumonia.

Causes of aspiration pneumonia can be secondary to regurgitation and vomiting, especially if esophageal dilation is present.

Conclusions

Differential Diagnoses for megaesophagus

• Acquired megaesophagus
  • Severe esophagitis
    • Gastroesophageal reflux
    • Ulceration from neoplasia
    • Foreign object
  • Idiopathic
  • Myasthenia gravis
  • Dysautonomia
  • Peripheral neuropathies
  • Laryngeal paralysis
  • Thymoma
  • Etc.
• Congenital megaesophagus
  • Pathophysiology remains unclear

The Alveolar Pulmonary Pattern

Air bronchograms represent air in the bronchial lumen, surrounded by relatively homogeneous increase in lung opacity

• This lung opacity causes border effacement of lobar vessels, bronchial walls, cardiac silhouette, and/or diaphragm.
• The bronchial wall itself is not seen
• When the bronchus is filled with soft tissue opacity, it will appear homogeneous, indistinguishable from a solid tissue structure such as a mass.

A time lag between the onset of clinical signs and radiographic signs is often observed, and a similar time lag may occur during healing

• The radiographic lesion may persist for several days despite clinical improvement

References

Watrous BJ. Esophagus. In: Thrall DE, editor. Textbook of Diagnostic Veterinary Radiology. St. Louis: Saunders Elsevier; 2007. p. 495-511.

Lamb CR. The Canine and Feline Lung. In: Thrall DE, editor. Textbook of Diagnostic Veterinary Radiology. St. Louis: Saunders Elsevier; 2007. p. 591-608.