Cats have thirteen pairs of ribs. The first 9 of these attach to the ventral sternum by way of costal cartilage. The next three pairs are variably attached to each other and the sternum and the thirteenth pair are floating ribs and have no association with the sternum.

Right Rib

(Posterior view)

The major features of a rib are the head, neck and tubercle.

Note how in a posterior view the tubercle angles posteriorly.

To determine the side a rib originates from hold the rib so the head is oriented medially and the tubercle angles toward you. In this position, the hand you are holding the rib in is the side of the cat it came from. If the tubercle does not angle toward you, you are holding the rib in the wrong hand.

13 Ribs from the Right Side

(Posterior view)

Note how the ribs change moving posteriorly. The size of the tubercle decreases and is absent on the last three ribs.

To thoracic vertebrae