Fig 2. Calculation of Proportional muzzle length ratio (M%).

Cranial length is defined as the horizon-line distance (mm) from the dorsal tip of the nose to the occipital protuberance (b’-c). Muzzle length is the horizon-line distance (mm) from the dorsal tip of nose to the nasal stop (b’-b). In the event that the dorsal tip of the nose is in line with the nasal stop a zero value is assigned. For this picture M% = 7.89% ([muzzle length 6mm / cranial length 76mm] *100). Note for readers: measurements will differ based on the size of viewed image.