Why Brachycephalics Reflux: New Study Maps Cervical Esophageal Alterations

Anatomical Differences of the Cervical Esophagus in Brachycephalic Dogs

Thais Isaias Santos, Daniel Marques Leopoldino Guerra, Giulia Vasquez Chiarato dos Santos, Danuta Pulz Doiche, Fabrício Singaretti de Oliveira

Background

Brachycephalic dogs (e.g., French Bulldogs, Shih Tzus, Pugs) are predisposed to gastroesophageal disorders, including reflux and esophageal dysfunction, often causing regurgitation, vomiting, and dysphagia. These functional issues may be linked to anatomical deviations. Prior imaging studies documented higher rates of reflux, esophageal wall thickening, and hiatal hernia in brachycephalic breeds. This study aimed to characterize anatomical differences in the cervical esophagus through cadaveric dissection.

Methods

Thirty-two adult dog cadavers (16 brachycephalic, 16 mesocephalic controls) were dissected under standardized conditions. The brachycephalic group included 13 Shih Tzus and 3 French Bulldogs. After thawing and fixation, dissections exposed the cervical esophagus and trachea from mandibular angle to thoracic inlet. Relationships between esophagus, trachea, and major vessels were photographed and diagrammed.

Results

Ventral esophageal sacculation was identified in 93.75% of brachycephalic dogs—100% of French Bulldogs and 92.3% of Shih Tzus. At the thoracic inlet, the esophagus was displaced ventrally and laterally, overlapping the trachea and obscuring its left lateral view in 93.75% of cases. This contrasted with mesocephalic controls, where the trachea remained fully visible. The esophagus also lay closer to the left common carotid artery in brachycephalic dogs.

Limitations

The study’s sample overrepresented Shih Tzus (81.25%), limiting interbreed comparisons. Cadaver-based methods may not fully represent functional dynamics in live dogs. Small numbers of French Bulldogs restricted breed-specific conclusions.

Conclusions

Cervical esophageal alterations—ventral sacculation and displacement overlapping the trachea—were highly prevalent in brachycephalic dogs. These features may contribute to reflux, dysphagia, aspiration risk, and complicate airway surgery due to altered vascular relationships and esophageal fragility. Breed-specific anatomical knowledge should inform clinical and surgical management of brachycephalic dogs.

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