Retrospective analysis of esophageal imaging features in brachycephalic versus non-brachycephalic dogs based on videofluoroscopic swallowing studies.

backgroundIdiopathic esophageal dysmotility (ED) is increasingly recognized in young dogs of brachycephalic breeds. Few studies have objectively associated specific videofluoroscopic swallowing study (VFSS) features with brachycephaly, leading to under-recognition of ED in brachycephalic breeds. HYPOTHESIS/

objectivesTo describe and compare VFSS in brachycephalic dogs versus non-brachycephalic dogs presented for dysphagia or regurgitation, and to investigate associations between these imaging findings and patient signalment.

methodsRetrospective analysis of VFSS of dogs presented for dysphagia or regurgitation (not megaesophagus) from 2006 to 2017. Cases were divided into brachycephalic and mesaticephalic breeds. The VFSS were reviewed using a standardized protocol by 2 examiners. Esophageal motility was assessed using specific criteria, and particular imaging features were noted and graded. Fisher's exact test was used to determine associations among signalment (including brachycephaly), final diagnosis, outcomes, and ED features.

resultsThirty-six dogs were included (n = 10 normal, n = 26 presumed ED). Twenty dogs (77%) with presumed ED were brachycephalic with a median age of 1 year (range, 0.2-10.5 years). Most common were prolonged esophageal transit time (ETT; n = 21/26), decreased propagation of secondary peristaltic waves (n = 20/26), and gastroesophageal reflux (GER; n = 18/28). Eight dogs (all brachycephalic) had hiatal herniation (HH). Morphological esophageal variations were only observed in brachycephalic dogs. Brachycephaly was significantly associated with ED (P = .005), prolonged ETT (P = .41), GER (P = .02), and HH (P = .03). CONCLUSIONS AND CLINICAL IMPORTANCE: The majority of dogs with presumed ED was young and brachycephalic and had specific abnormalities that were less frequent in mesaticephalic dogs with regurgitation or dysphagia.