Laryngeal and pleural ultrasound and elastography (ARFI) in dogs with brachycephalic obstructive airway syndrome

Abstract The aim of the present study is to evaluate pleural thickness and stiffness and the laryngeal stiffness in dogs clinically affected by brachycephalic obstructive airway syndrome using B-mode ultrasound and acoustic radiation force impulse elastography. Fifty-two brachycephalic, pugs and French bulldog, clinically classified as brachycephalic obstructive airway syndrome (BOAS) grades 0, I, II and III were included and 15 mesocephalic beagle dogs used as a control group. All animals underwent B-mode ultrasound and subsequent elastography of the pleura and arytenoid cartilage of the larynx. Brachycephalic dogs showed greater pleural thickness over mesocephalic group (p = 0.04). Also showed lower pleural shear wave velocity than the mesocephalic group (p = 0.04), The larynx shear wave velocity was similar between types of skull and BOAS grades (p = 0.80). Measurements of pleural line thickness and pleural stiffness showed moderate capacity for diagnosing brachycephalic syndrome (p = 0.01, cut-off value of > 0.82 mm and p = 0.04, cutoff value 3.29 m/s), with low sensitivity and good specificity. However, shear wave velocity measurements of the larynx were not statistically significant for the diagnosis of brachycephalic syndrome. The results suggest a secondary change to the inspiratory effort, at the tissue level of the pleura in dogs clinically affected by BOAS, which can be identified by B-mode ultrasound and elastography methods, but it was not possible to diagnose changes in the arytenoid cartilage.