Table 9 Summary of transformations performed prior to analysis

Palpebral aperture

Measurement between lateral canthi (M9) minus that of medial canthi of eyes (M10).

Eye separation relative to cranium length

Cranial length (M2) divided by distance between medial canthus of each eye (M10).

Rostrocaudal doming

Length across the top of the cranium (M3) divided by length of cranium (M2)

Lateral doming

Width across the top of the cranium directly behind the zygomatic arches (M5) divided by the width of the cranium at that point (M6).

Zygomatic arch deviation from cranium

Width over both zygomatic arches at the widest point (M7) minus the width of the cranium directly caudal to zygomatic arches (M6). This is then divided by the width over the zygomatic arches (M7).

Cephalic index

The width of the cranium (M6) (Figure 10; yellow) divided by its length (M2) (Figure 10; red).

Craniofacial index (typically referred to as cephalic index in dogs)

The width of the cranium (M6) (Figure 10; yellow) divided by length of cranium and muzzle (M1) (Figure 10; blue).