Muzzle

The correct head to muzzle proportions are 6:4.

Correct head to muzzle ratio

Presa Canario Correct Head ratio

Muzzle too short

Presa Canario Muzzle Too Short

Muzzle too long

The upper flews are pendulous, although not excessively, and seen from the front, form an inverted "V" where they join.

Presa Canario V Shaped Lips
V shaped lips. Sufficient flews. Correct

Presa Canario U Shaped Lips
U shaped lips. Incorrect.

Correct flews

Flews overly developed

Presa Canario Flews Over Developed

Excessive flews

Flews too tight

Presa Canario Flews Too Tight

Nose

Presa Canario Head

Bridge of the nose is flat and shows a straight profile without ridges