Skip to main content
. 2019 May 16;15(5):e1008102. doi: 10.1371/journal.pgen.1008102

Fig 1. Morphology and respiratory distress.

Fig 1

Lateral head profiles of the (A) brachycephalic Pug, (B) mesocephalic Norfolk Terrier, (C) mesocephalic Norwich Terrier and (D) dolichocephalic Smooth Collie. Images are not to scale. (E) Measurements of the canine hard palate normalised for skull size indicate that the rostrum shape of the Norwich Terrier and Norfolk Terrier is intermediate to that of extreme brachycephalic (Pug) and dolichocephalic (Smooth Collie) dogs. Mann-Whitney-Wilcoxon and Kolmogorov-Smirnov tests <0.05 *; <0.01 **; <0.001 ***. (F) Geometric morphometric analysis of 96 domestic dog breeds reveals that the Norwich Terrier and Norfolk Terrier occupy a distinct morphospace from the brachycephalic breeds such as the Pug, the latter which is susceptible to BOAS. Skull size is scored by neurocranium centroid size (y-axis) and skull shape is scored by viscerocranium PC1 (x-axis). Photo credits: Matthew Carr (Pug), Anne Johnsen (Norfolk Terrier), Dan Kyprianou (Norwich Terrier), Bev White (Smooth Collie).