Most wild dogs and dogs originated by natural selection look like this. And than, we have dogs, that look much different from them. Not only their bodies, size and coat is different, but also their heads look extremely different. So what is the reason for it? Well, of course, the answer is selective breeding.
When people thought that different head shape would be beneficial for certain function, they started selectively breeding and creating the ideal head type for that kind of a job. And over the time, the shape of a dog’s skull has evolved into primarily three broad categories – the dolichocephalic skull, mesocephalic skull and brachycephalic skull. Lets talk about each category individually.
The most proportional is the mesocephalic skull. It is the medium skull and most of the wild and primitive dogs have this type of a skull. It is no coincidence, that this type of a skull have the fewest head and neck related issues.
This skull is sometimes also known as Square skull and dogs with this type of a head have broader snouts and larger nasal cavites, which is why they have extremely good sense of smell.
Some examples of breeds with mesocephalic skull are Alaskan Malamutes, Beagles, Belgian Shepherds, Border Collies, Dalmatians, Cocker Spaniels and most of the other Spaniels as well, Irish Setters, Siberian Huskies or Labrador and Golden Retrievers.
Than we have the long headed dogs, whose skull is known as dolichocephalic. Most of the dogs with dolichocephalic head were bred to have excellent sight, mostly for hunting purposes. Dolichocephalic skulls provide higher range of vision due to the long and narrow snout. Dogs that were used in racing events or to chase down prey were also bred to have long, thin, streamlined heads.
The problem with dolichocephalic skull is, that extremely narrow skulls may have problems with eye formation, overbites and not enough room for incisor teeth to fit properly.
Dogs that would fit into this category includes most of the sighthounds like Greyhound, Afghan Hound, Borzoi, Saluki or Whippet. In sighthounds, the long skull is most visible, but dogs like Fox Terrier, Rough Collie, Pharaoh Hound, Manchester Terrier, Doberman or Dachshund also have slightly longer skull and they can be included into dolichocephalic breed group as well.
The last group are short nosed dogs, also known as brachycaphelic dogs. This type is most often connected with serious health issues like breathing problems and overheating, but originally, for example Bulldogs, were bred to have short muzzles to function as a fierce weapon for use in bull-baiting and dog fights. The utility of the skull compression was to achieve strong jaws.
Brachycaphelic heads are often times bred to extremes, because many people find it cute and actually want dogs with extremely short muzzles and large human like eyes. But of course, if you push the limits of the dogs head, than you will create a lot of very bad health issues.
When the shape of the skull is distorted, the space into which the teeth erupt can be distorted as well. This results in teeth that don’t fit together properly. Breathing issues are another big problem with brachycaphelic dogs, but again, this problem started to be serious only when we started to breed dogs to their extremes. Some brachycaphelic breeds are absolutely healthy.
The list of Brachycaphelic dogs include all kinds of Bulldogs, Pit Bulls, Boxers, Brussels Griffons, Chow Chow, all kinds of Mastiffs, or Pugs.
The names of the skull types are pretty complicated, which is why dog breeders, owners and fanciers created several other names for these heads. Those include Apple Head, which is a rounded with a dome like skull head. The example of the Apple head is Chihuahua. The blocky head, which is square and cube-shaped and it is the Boston Terriers head. Domed head, which is convex and even rounded top skull, like Cocker Spaniels head. Broken-up face with receding nose and with a deep stop and undershot jaw like Pekingese. The Down face, where the muzzle has a convex incline from the top of the skull to the tip of the nose like Bull Terrier. The Dish face which is a head with a profile that forms a slightly concave shape. The example of this kind of a head is a Pointer. And last but not least the snippy face, which is a pointed, thin muzzle without much depth or width and the typical example is Saluki.
It is important to say, that even though the medium skull, the mesocephalic skull is connected with the least health issues, there is no guarantee that if you will buy the mesocephalic dog he will not suffer from any ilnesses. But you should be very careful when you will buy a breed with skull that is extremely long or short as those dogs truly suffer much more from different health issues and you should buy this kind of breed only from reputable breeder with a long history of healthy dogs. But of course, you should always buy any dog from reputable breeder.