Boxer (Canis familiaris)
Quick thanks to @blackbackedjackal for letting me use Faust c:!
Boxers are a large working breed that originates from Germany. They were bred for bull baiting and guard work, and are still used for the latter today. They're a breed known for their brachycephalic skulls and the problems associated with them.
Brachy faces are commonly associated with smaller dog breeds, but boxers are one of the several larger brachy breeds. They may not look too bad on the outside, but their skulls are often very disproportionate and misshapen. Despite this, boxers are still semi-athletic dogs, leading to an array of respiratory complications. The degree of the push-back highly depends on the bloodlines of the individuals.
This breed varies enough in weight and size that it'll ultimately show in the skull. Boxers can weigh anywhere from 65-80 pounds, so you'll get several inches of difference in the skull. Skulls could measure 8-10 inches, possibly more if the dog is exceptionally large. If the size doesn't help, look at the shape. Boxers are blocky and square like most brachy breeds. Their muzzles and cranium both display that definitive square look. It's an easy giveaway to look for.
Not many dogs can boast such a visually offensive stop. Boxers can, and do so with gusto. They have sharp “cliff” drops that are nearly 90° in some cases. Such a drastic stop brings their eyes forward, making them nearly parallel with the stop itself.
As a result of the leveled eyes and square heads, boxers have very wide, bowed out zygomatic arches. The arches themselves are thick, as there are powerful muscles from the jaws and sagittal that attach to them. The eye sockets are also very large, which lends to how much the arches push outward.
Dogs historically used for bullfighting or guarding purposes will display the traits that were originally bred in, even as they are changed over time. Boxers, like most mastiff like dogs, have big, wide nasal passages. Paired with their wrinkled faces in life, this is the perfect combination for a sustained, locked bite. The wrinkles kept blood away from their eyes, and the big nose meant they could still draw powerful breaths of air into their lungs. They could hold on and continue to breath, which was important. Guarding and fighting calls for good endurance, which would be off the table with a smaller, more delicate nose. However, though earlier boxers were less limited sinus wise doesn’t mean the same can be said for modern boxers. The visual look has remained, albeit modified, but the functionality of their respiratory system may as well have been cut in half by said modifications.
Their teeth will be a giveaway. Not every boxer will have an underbite, but it's uncommon to see one without. Since they’re brachy, and it tends to be an issue among brachy dogs, they may display crowding in their teeth. This could turn teeth sideways, displace them out of the natural line, or could even result in some teeth being totally missing. This has to do with them having such a short upper jaw. The lower jaw doesn't display these issues as often, but they definitely aren't exempt from it.
All-in-all, Boxers are an easy breed to identify. They're a larger brachy breed with an incredibly square composition, a drastic stop, and big eyes and arches. There are a lot of key features to them that make them a breed that won't give you too much trouble. Even then, it's good to use references when you're trying to ID them; It'll save some possible frustration.
Good luck, and happy identifying!
Ko-Fi