As I'm sure you know (in humans that is) the skull is made up of many bones. Well, it is the same for animals. The rough anatomical regions of the skull are the face, mandible and cranium (or "brain box", though that term sounds somewhat unprofessional at the best of times).
The skull is formed from two kinds of bones (embryologically speaking). The bones of the skull are endochondral bones (from cartilaginous structures and are usually unpaired) and intramembronous (From mesenchyme of the embryo (I'm sure I'll get around to discussing what that is at one point but basically it's a type of embryological tissue). The intramembranous bones are usually paired and are usually plate like.
Each of the bones shown in the picture of the cat skull are paired (each have a partner of the same shape on the opposite side of the skull).
Now bones, though solid also have quite a few holes in them (to allow for the passage of different nerves and sometimes blood supply). Not shown here but usually found in the maxilla near the orbit (eye socket) is a hole called the infraorbital foramen. Through this hole a nerve leaves the skull to innervate the upper lip and the whiskers of the animal.
Also not shown here but perhaps in another image...

infections or chips can hurt!).
The bones of the palate (hard palate which underlies the softer tissue you can feel with your tongue (in your mouth that is) are also part of the skull. There are all sorts of bones in the head as I'm sure you can now appreciate. Issues that can happen in this area is a failure of the secondary palate to close (the bony palate) it is called an oronasal fistula or cleft palate and leaves an open connection to the nasal cavity from the roof of the mouth. This is usually first picked up in puppies or kittens as milk comes out of their noses when they try to feed. Cleft palate is both serious (great risk of them breathing in milk) and hard to fix. Surgery here is the only option though ay not always be successful. If the primary palate fails to close it is called a cleft lip (which is more cosmetic than damaging though there is a possible increase in nasal infections). Both of these need a surgical fix.

Also visible on this skull is the incisive foramen (or palatine fissure). This is where the vomeronasal organ (or Jacobson's organ) sits. That gland is a really neat sensory gland (you've probably seen horses flip their lips upwards and make a funny face, this is called Flehmen and it's them utilizing their vomeronasal organs to scent pheromones or something new). Usually this is described in stallions "smelling" a mare in heat but both sexes do this when they smell something new, or something interesting. Flehmen forces air into the nasal cavity through slits in the hard palate forcing it through the vomeronasal organ.
Other animals (ie cats) have this ability as well.


The back of the skull also comes into play. It's where the spinal cord leave the brain to be covered with, well, spine. It too has some clinical implications. Most recently issues with the bones around the foramen magnum (big hole where the spinal cord leaves through) have been implicated in a disease recognized in the dog breed the Cavalier King Charles Spaniel. In this breed, due to selective breeding to create a smaller dome shaped head the occipital bone is too reduced and compresses the cerebellum against the foramen magnum, as a result the trapped fluid creates lesions in the brain, neuralgia (nerve pain) and can result in the dog being in a great amount of pain. The disease itself is called syringomyelia.

Finally.... Head shapes.. Just like ears they come in all shapes and sizes. In dogs and cats they are most commonly described as Dolicocephalic (long pointy noses like greyhounds and siamese cats), Mesocephalic (like the german shepherd and the common domestic shorthair cat) and Brachycephalic (bulldogs and persian cats). As with everything else, there can be clinical implications here too.

Riiiight, so it may not be a dog ...
but I felt that Pacman deserved at least a nod in the reduced skeleton department
This was so helpful, thanks!! :)
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