Nasopharyngeal collapse can be identified on radiography in healthy male Beagle dogs without cardiopulmonary diseases.

Pharyngeal collapse has been described as a decrease of more than 50% in the diameter of the lumen. However, there has been no study on changes in the pharyngeal lumen in clinically normal dogs. The hypothesis of this prospective, observational, and pilot study was that change in nasopharyngeal lumen would be over 50% in Beagle dogs without cardiopulmonary diseases. Thus, we assessed the nasopharyngeal luminal change using cervical radiography in Beagle dogs without respiratory signs or cardiac abnormalities. The study sample included 42 Beagle dogs without cardiopulmonary diseases. Cervical radiographies were acquired during inspiration and expiration, and nasopharyngeal luminal change (%) was calculated. The median nasopharyngeal luminal change was 16.6%, and nasopharyngeal luminal change over 50% was identified in two dogs. The nasopharyngeal luminal change was significantly associated with body condition score and body weight. There was no correlation between nasopharyngeal luminal change and age. This study revealed that change in nasopharyngeal lumen over 50% can be identified in Beagle dogs without cardiopulmonary diseases and may be over-diagnosed as partial pharyngeal collapse. Further studies for comparing change in nasopharyngeal lumen between clinically normal dogs and dogs with respiratory signs are warranted.