Fluoroscopic characterization of pectus excavatum in dogs: a cross-sectional study

The dynamic respiratory abnormalities in dogs with pectus excavatum are incompletely characterized.

To characterize fluoroscopic findings in dogs with pectus excavatum and evaluate their associations with clinical severity.

Fifty-three client-owned dogs with pectus excavatum.

Cross-sectional study. Dogs were classified into low-severity or high-severity groups based on respiratory signs and treatment. Fluoroscopic examinations were evaluated for pectus excavatum-intrinsic findings and concurrent respiratory abnormalities. Associations with clinical severity were assessed using univariable and multivariable analyses.

Multiple fluoroscopic findings of pectus excavatum were characterized. Paradoxical sternal movement was independently associated with clinical severity (odds ratio [OR] 3.71, 95% CI, 1.03-13.4; P = .045). Thoracic height reduction ratio was significantly higher in the high-severity group (0.140 [IQR, 0.100-0.228]) compared with the low-severity group (0.097 [IQR, 0.064-0.133]; P = .04). Mainstem bronchial collapse was present in all dogs (53/53, 100%) and cervical lung lobe herniation in 50/53 (94%; 95% CI, 84%-99%). Most other fluoroscopic variables showed no significant associations with clinical severity.

Paradoxical sternal movement, particularly with greater thoracic height reduction, may serve as a supportive indicator of clinical severity. The high prevalence of bronchial collapse and cervical lung lobe herniation suggests an association between pectus excavatum and these airway abnormalities in dogs.