Did you know that the foundation for the muscles in your dog’s chest is impacted by the shape of his rib cage? 

Not surprisingly, ribs became larger and more circular with increasing rib number. To determine the shape of ribs, scientists used an algorithm where ribs were fit by an ellipse of the form where  ξ and η are the transformed X- and y-axes in the plane of the rib, ξo is the ξcoordinate of the center of the ellipse in the sagittal midplane, and R1 and R2 are the anteroposterior and lateral radii of the rib. Just use the equation below to guide you.

Or, you could take our word for it that why this matters has to do with a dog’s ability to move properly. Heavier muscling that’s seen on, say, a barrel ribbed dog, can result in what we call “loaded shoulders.” The dog will move out at the elbows and wide, and suffer inefficient movement and limited endurance.  The shape of a dog’s rib cage will also vary between breeds because what the dog’s job is can make a difference.  The Bulldog has, according to its breed standard, “well-rounded ribs,” will allows these dogs to stand their ground. It follows that its shoulders “should be muscular, very heavy, widespread and slanting outward, giving stability and great power.”

The equation we included above came from an abstract on the geometry and kinematics of dog ribs that serious dog geeks may find interesting.

We don’t do math if we can help it.

*Trivia:  The most decorated Marine in the history of the Corps, the only Marine to be awarded the Navy Cross five times, was the legendary Lt. Gen. Lewis B. “Chesty” Puller. Outspoken and tenacious as hell, the man who enlisted as a private ended his career as a Lieutenant General.  “Good Night, Chesty, Wherever You Are” is an often used tribute of respect to the man said by Marines who remember. It is because of this man that the Marine Corps mascot, always an English Bulldog, is always named “Chesty.”  And now you know.

Image: “Double Trouble” by Harold Shull is available in various two-dimensional formats here.