The cephalic index of a vertebrate is the ratio between the width (side to side) and length (front to back) of its cranium (skull). This ratio does not concern the muzzle or face, and thus is distinct from the craniofacial ratio, which compares the size of the cranium to the length of the muzzle. The two measures are often confused in descriptions of dog breeds.
The cephalic index is used to classify animals into three groups:
Brachycephalic (literally 'short-headed'): the length of the cranium is shorter than the width, giving the top and sides of the cranium a round shape, often referred to as 'apple-head'.
Mesaticephalic or mesocephalic ('middle-headed'): the length and width are equal, giving a square shape. When dealing with animals, especially dogs, the more appropriate and commonly used term is not "mesocephalic", but rather "mesaticephalic", which is a ratio of head to nasal cavity. [1] [2]
Dolichocephalic ('long-headed): the length is greater than the width.
Breeds of each group are listed in Cephalic index.
The cephalic index or cranial index, the ratio of the maximum width of the head of an organism multiplied by 100 and then divided by their maximum length. The index was once used to categorize human beings in the first half of the 20th century, but today it is used to categorize dogs and cats.
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, these two parts are the neurocranium and the viscerocranium that includes the mandible as its largest bone. The skull forms the anterior-most portion of the skeleton and is a product of cephalisation—housing the brain, and several sensory structures such as the eyes, ears, nose, and mouth. In humans these sensory structures are part of the facial skeleton.
The Dinaric race, also known as the Adriatic race, were terms used by certain physical anthropologists in the early to mid-20th century to describe the perceived predominant phenotype of the contemporary ethnic groups of southeast Europe.
Brachycephaly is the shape of a skull shorter than typical for its species. It is perceived as a desirable trait in some domesticated dog and cat breeds, notably the pug and Persian, and can be normal or abnormal in other animal species. In humans, the cephalic disorder is known as flat head syndrome, and results from premature fusion of the coronal sutures, or from external deformation. The coronal suture is the fibrous joint that unites the frontal bone with the two parietal bones of the skull. The parietal bones form the top and sides of the skull. This feature can be seen in Down syndrome.
The Bulldog is a British breed of dog of mastiff type. It may also be known as the English Bulldog or British Bulldog. It is a medium sized, muscular dog of around 40–55 lb (18–25 kg). They have large heads with a thick folds of skin around the face and shoulders, and a relatively flat face with a protruding lower jaw. The breed has significant health issues as a consequence of breeding for its distinctive appearance, including brachycephalia, hip dysplasia, heat sensitivity, and skin infections. Due to concerns about their quality of life, breeding Bulldogs is illegal in Norway and the Netherlands.
The Boxer is a medium to large, short-haired dog breed of mastiff-type, developed in Germany. The coat is smooth and tight-fitting; colors are fawn, brindled, or white, with or without white markings. Boxers are brachycephalic, have a square muzzle, mandibular prognathism, very strong jaws, and a powerful bite ideal for hanging on to large prey. The Boxer was bred from the Old English Bulldog and the now extinct Bullenbeisser, which became extinct by crossbreeding rather than by a decadence of the breed. The Boxer is a member of both The Kennel Club and American Kennel Club (AKC) Working Group.
The Rottweiler is a breed of domestic dog, regarded as medium-to-large or large. The dogs were known in German as Rottweiler Metzgerhund, meaning Rottweil butchers' dogs, because their main use was to herd livestock and pull carts laden with butchered meat to market. This continued until the mid-19th century when railways replaced droving. Although still used to herd stock in many parts of the world, Rottweilers are now also used as search and rescue dogs, guard dogs, and police dogs.
The Boston Terrier is a breed of dog originating in the United States of America. This "American Gentleman" was accepted in 1893 by the American Kennel Club as a non-sporting breed. Color and markings are important when distinguishing this breed from the AKC standard. They should be either black, brindle or seal with white markings. Boston Terriers are small and compact with a short tail and erect ears. The AKC says they are highly intelligent and very easily trained. They are friendly and can be stubborn at times. The average life span of a Boston Terrier is around 11 to 13 years.
A mastiff is a large and powerful type of dog. Mastiffs are among the largest dogs, and typically have a short coat, a long low-set tail and large feet; the skull is large and bulky, the muzzle broad and short (brachycephalic) and the ears drooping and pendant-shaped. European and Asian records dating back 3,000 years show dogs of the mastiff type. Mastiffs have historically been guard dogs, protecting homes and property, although throughout history they have been used as hunting dogs, war dogs and for blood sports, such as fighting each other and other animals, including bulls, bears and even lions.
Craniometry is measurement of the cranium, usually the human cranium. It is a subset of cephalometry, measurement of the head, which in humans is a subset of anthropometry, measurement of the human body. It is distinct from phrenology, the pseudoscience that tried to link personality and character to head shape, and physiognomy, which tried the same for facial features. However, these fields have all claimed the ability to predict traits or intelligence.
Canine terminology in this article refers only to dog terminology, specialized terms describing the characteristics of various external parts of the domestic dog, as well as terms for structure, movement, and temperament. This terminology is not typically used for any of the wild species or subspecies of wild wolves, foxes, coyotes, dholes, jackals or the basal caninae. Dog terminology is often specific to each breed or type of dog. Breed standards use this terminology in the description of the ideal external appearance of each breed, although similar characteristics may be described with different terms in different breeds.
A head is the part of an organism which usually includes the ears, brain, forehead, cheeks, chin, eyes, nose, and mouth, each of which aid in various sensory functions such as sight, hearing, smell, and taste. Some very simple animals may not have a head, but many bilaterally symmetric forms do, regardless of size.
A snout is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw. In many animals, the structure is called a muzzle, rostrum, or proboscis. The wet furless surface around the nostrils of the nose of many mammals is called the rhinarium. The rhinarium is often associated with a stronger sense of olfaction.
The Dogue de Bordeaux, Bordeaux Mastiff, French Mastiff or Bordeauxdog is a large French mastiff breed. A typical brachycephalic mastiff breed, the Bordeaux is a very powerful dog, with a very muscular body. This muscular breed has been put to work pulling carts, transporting heavy objects, and guarding flocks.
Dog anatomy comprises the anatomical studies of the visible parts of the body of a domestic dog. Details of structures vary tremendously from breed to breed, more than in any other animal species, wild or domesticated, as dogs are highly variable in height and weight. The smallest known adult dog was a Yorkshire Terrier that stood only 6.3 cm (2.5 in) at the shoulder, 9.5 cm (3.7 in) in length along the head and body, and weighed only 113 grams (4.0 oz). The heaviest dog was an English Mastiff named Zorba which weighed 314 pounds (142 kg). The tallest known adult dog is a Great Dane that stands 106.7 cm (42.0 in) at the shoulder.
Cephalometry is the study and measurement of the head, usually the human head, especially by medical imaging such as radiography. Craniometry, the measurement of the cranium (skull), is a large subset of cephalometry. Cephalometry also has a history in phrenology, which is the study of personality and character as well as physiognomy, which is the study of facial features. Cephalometry as applied in a comparative anatomy context informs biological anthropology. In clinical contexts such as dentistry and oral and maxillofacial surgery, cephalometric analysis helps in treatment and research; cephalometric landmarks guide surgeons in planning and operating.
The Pug is a breed of dog originally from China, with physically distinctive features of a wrinkly, short-muzzled face, and curled tail. The breed has a fine, glossy coat that comes in a variety of colors, most often fawn or black, and a compact, square body with well developed and thick muscles all over the body.
The American Bully is a modern breed of dog that was developed as a companion dog, and originally standardized and recognized as a breed in 2004 by the American Bully Kennel Club (ABKC). Their published breed standard describes the dog as giving the "impression of great strength for its size". In 2008, the American Bully was recognized by the European Bully Kennel Club (EBKC), and on July 15, 2013, by the United Kennel Club (UKC). Neither The Kennel Club nor American Kennel Club (AKC) have recognized or accepted the American Bully into their registry as a purebred dog. The founding registry (ABKC) divided the American Bully into four categories, including the Pocket, Standard, Classic, and XL, whereas other registries, including the UKC, have approved one consistent size standard.
Brachycephalic airway obstructive syndrome (BAOS) is a pathological condition affecting short nosed dogs and cats which can lead to severe respiratory distress. There are four different anatomical abnormalities that contribute to the disease, all of which occur more commonly in brachycephalic breeds: an elongated soft palate, stenotic nares, a hypoplastic trachea, and everted laryngeal saccules. Because all of these components make it more difficult to breathe in situations of exercise, stress, or heat, an animal with these abnormalities may be unable to take deep or fast enough breaths to blow off carbon dioxide. This leads to distress and further increases respiratory rate and heart rate, creating a vicious cycle that can quickly lead to a life-threatening situation.
The Alapaha Blue Blood Bulldog is a breed of bulldog from the United States, and it is predominantly used as a guard dog. It is a very powerful, muscular breed with large head and brachycephalic muzzle. The hair coat is short, typically colored white with black, blue, buff or brown patches, and its tail is kept un-docked. Sexual dimorphism is common in the breed, with larger dogs typically twice the weight of smaller bitches.