Inhaled grass awns, the sharp and sometimes barbed seeds of grasses, commonly cause respiratory disease during spring and summer, especially in hunting dogs.1–3 Acute inhalation often goes unnoticed by the owner, and awns can subsequently migrate through the airways into the lungs, pleural space, pericardium, retroperitoneal cavity, or sublumbar muscles, or through the thoracic wall.3–8 Migrating grass awns cause severe inflammatory tissue reactions and sepsis. The clinical signs can vary, depending on the location of the foreign material. Grass awn migration into the lungs or pleural space commonly causes lobar pneumonia, abscessation, pneumothorax, pyothorax, or a combination of conditions. Treatment generally requires removal of the foreign material, debridement of abscesses or granulomas, and antimicrobial administration and can necessitate lung lobe resection or prolonged pleurocentesis.3,5,6,8–10
Foreign bodies such as grass awns in the bronchi can be successfully removed by bronchoscopic methods, preventing further migration.11 For grass awns that have migrated into other body tissues or cavities, evaluation by diagnostic imaging methods such as ultrasonography, CT, or MRI aids in the initial diagnosis and is useful for determining anatomical landmarks that can be used in surgical planning. Ultrasonography has been previously used to detect, localize, and guide removal of grass awn foreign bodies in dogs.2,3,5,6,12,13 Recently, transesophageal ultrasonography was used to visualize a migrating grass awn within the pulmonary parenchyma of a dog and to guide subsequent thoracoscopic removal of the plant material.14 Computed tomographic imaging has been used to identify and localize foreign bodies but does not always permit visualization.3 Magnetic resonance imaging has also been used to visualize an abnormal, low-signal linear structure, consistent with a migrating grass awn, in the thoracic region of the spinal cord of a dog.15
Use of transthoracic, transesophageal, and intraoperative ultrasonography to detect migrating intrathoracic grass awns is limited to few clinical reports or case series.3,5,9,12,14 The purpose of the study reported here was to describe the ultrasonographic findings and outcomes for dogs with suspected migrating intrathoracic grass awns seen at a veterinary teaching hospital over a 3-year period.
No third-party funding or support was received in connection with this study or the writing or publication of the manuscript. The authors declare that there were no conflicts of interest.
The authors thank Ivano De Marco for the analysis of the plant material and Massimiliano Porretta for technical support.
MyLab 30 Vet Gold, Esaote, Genoa, Italy.
Delta Med Medical Devices, Viadana, Italy.
Karl Storz, Verona, Italy.
Auto Suture Endo-GIA Universal Roticulator, Covidien, Mansfield, Mass.
Auto Suture TA90, Tyco Healthcare, Norwalk, Conn.
Smiths Medical PM, Waukesha, Wis.
Ocean Water Seal Chest Drain, Atrium Medical Corp, Hudson, NH.
Argyle, Covidien, Mansfield, Mass.
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