Appearance A portrait showing the breed's distinctive head.First introduced to the world outside of Spain's Canary Islands by the American Anthropologist, Dr. Carl Semencic in an article for Dogworld Magazine and in his books on the subject of rare breeds of dogs, the Presa Canario, or "Canary Dog" is a large sized dog with a thick and muscular body. The head is broad, massive, square, and powerful. Proper head and good expression are part of the breed standard, and are manifest in the best breed specimens. The ears are normally cropped both to create a more formidable expression, and to prevent damage while working with cattle. If cropped the ears stand erect. In countries where ear cropping is banned the ears are close fitting to the head, they hang down and should be pendant or "rose" shaped. The lips are thick and hang in an inverted V where they join; the flews may be slightly loose. The interior lips are dark.
Males average between 23 to 26 inches (58 to 66 cm) at the withers with a minimum weight of 100 pounds (45 kg). Females average between 22 to 25 inches (56 to 63 cm) at the withers with a minimum weight of 85 pounds (39 kg). Very high weights could lead to a number of health problems. Too much weight is also known to compromise the dog's athleticism and working ability.
The breed is also characterized by a sloping topline (with the rear being slightly higher than the shoulders). Another characteristic of the breed is the shape of the paws (cat foot) and the catlike movement of the animal. The body is mesomorphic, that is, slightly longer than the dog is tall, contributing to the feline movement. The Presa should be powerful, balanced, and imposing in appearance. It is heavily built, but able to move with great athleticism. Coat and color Silver Fawn Red Fawn Fawn Red Brindle Brown Brindle Fawn Brindle Reverse Brindle Verdino
The coat is short with no undercoating and slightly coarse to the touch. The coat comes in all shades of fawn and brindle. The acceptance of the black coat is a point of contention among fanciers as it is allowed by the AKC-FSS, UKC and UPPCC standards, but not by the FCI or FIC standards. White is allowed up to 20 percent and is most commonly found on the chest and feet, and occasionally on a blaze on the muzzle. The breed standard requires black pigmentation and dogs should have a black mask that does not extend above the eyes. The breed is known for its very minimal shedding. In order to be properly informed on the Presa Canario's coat and genetics. It's suggested to read the below section titled "Presa Canario – A Legislative Basis for the Name and Standard", there you will find the true "decreto of the Presa Canario" (i.e. The Presa Canario has a solid legislative basis in Spain, and it is recognized as such by a Real Decreto of the MAPA (Minister of Agriculture Fishing and Nutrition), which was published in the Official Gazzette of the Spanish Government ([BOE – Boletin Oficial del Estado]). The original [Real Decreto 558/2001] can be read on the site of the Spanish Government Gazzette. In this authentic legislative source the breed is named precisely as "Presa Canario." A breed standard is attached in the Real Decree and it includes the black coat and a maximum weight. Any other name or standard is not recognized by Spanish law.). Inside the Decreto you will find (page 7) the real presa's color (which includes gray/grey), here is a translated version of the colors section in the decreto, it reads (It seen distance the dog seems to be one-color and can have clearer excesses in the extremities. It seen closely, is to stand out that the color proceeds of the mixture of hairs of different tones: Brown, brown, more or less reddish, gray, white and black. The basic colors that derive from this mixture are: brown, in their clear tones, media and dark, gray composed of white, gray, and black, with shades that go of the gray silver one to the gray dark one. If it dominates the black one and combines simply with white, gives a black one that cold seems. There are also dogs with a mixture of black, brown and brown reddish, that can dominate in an or several you split, giving the impression of black specimens and coffee. Themselves they are not admitted you stain white or black. At times, a few white hairs, in the shape of star on the chest they are tolerated, or in the upper part of the fingers, but, in that case, anyway, does not owe this to come accompanied by white nails ). Coat genetics This section may contain original research. Please improve it by verifying the claims made and adding references. Statements consisting only of original research may be removed. More details may be available on the talk page. (December 2009)
Dogs have a great deal of diversity in breeds, in all aspects, including coat color and patterns. Canine coat genetics are still being researched. Most of our present understanding of canine coat genetics is based on the work of Clarence Cook Little, author of "Inheritance of Coat Color in Dogs" (1979), although some researchers dispute certain of his theories. For those with a keen interest in canine coat genetics, an excellent source for the breeder and the layperson's understanding is authored by Dr. Sue Ann Bowling 
As far as the Presa Canario is concerned, it is believed Fawn is based on the Agouti series, specifically the ay allele. Agouti hairs are fawn hairs banded and/or interspersed with black. This gene is recessive to the other genotype of the breed, brindle.
It is known that Brindle is a dominant trait but there is some argument as to where it is located. Little postulated that it was on the E series (Ebr) but if so, would compete with the black mask (Em), which is known to not be the case. Dr. Bowling speculates the gene is most likely on a new series, which she calls "K".
The following are true in canine coat genetics: (remembering alleles come in sets of 2)
1. Breeding fawn (ayay) x brindle (KbrKbr or Kbray) may produce: fawn and brindle offspring.
2. Breeding brindle (KbrKbr or Kbray) x brindle (KbrKbr or Kbray) may produce: fawn and brindle offspring.
3. Breeding fawn (ayay) x fawn (ayay) will always produce: fawn offspring.
For breedings of fawn x brindle or brindle x brindle there is no clear way to predict the number of fawn or brindle offspring. Some litters from these breedings will be entirely fawn, entirely brindle, or, most likely, some combination of both.